Desktop private modes

(default settings)
brave logo
brave
1.61

private
brave logo
brave
1.61

Tor
chrome logo
chrome
120.0

private
edge logo
edge
120.0

private
firefox logo
firefox
121.0

private
librewolf logo
librewolf
121.0-1

private
mullvad logo
mullvad
13.0

private
opera logo
opera
105.0

private
safari logo
safari
17.1

private
tor logo
tor
13.0

private
ungoogled logo
ungoogled
120.0

private
vivaldi logo
vivaldi
6.5

private
State Partitioning testsWhich browsers isolate websites to prevent them from sharing data to track you?
A common vulnerability of web browsers is that they allow tracking companies to 'tag' your browser with some data ('state') that identifies you. When third-party trackers are embedded in websites, they can see this identifying data as you browse to different websites. Fortunately, it is possible for this category of leaks to be fixed by partitioning all data stored in the browser such that no data can be shared between websites.
        
Alt-Svc
Alt-Svc allows the server to indicate to the web browser that a resource should be loaded on a different server. Because this is a persistent setting, it could be used to track users across websites if it is not correctly partitioned.
              
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: h3, h3, h3, h3, h3

result, different first party: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: h2, h2, h2, h2

unsupported: true, true, true, true

passed: undefined

test failed: false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: h3, h3, h3, h3, h3

result, different first party: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: h3, h3, h3, h3, h3

result, different first party: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: h3, h3, h3, h3, h3

result, different first party: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: h3, h3, h3, h3, h3

result, different first party: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: h3, h3, h3, h3, h3

result, different first party: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: h3, h3, h3, h3, h3

result, different first party: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: h3, h3, h3, h3, h3

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: h2, h2, h2, h2, h2

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: h3, h3, h3, h3, h3

result, different first party: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same first party: h3, h3, h3, h3, h3

result, different first party: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
blob
A 'blob URL' is a local reference to some raw data. Trackers can use a blob URL to share data between websites.
              
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: 
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: 
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Failed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c,
b4870a62-d8c7-4aa3-b869-a4b56ada1280,
49049c26-be88-49c3-aacd-606f570a5052,
f5068b02-e5d5-46da-b936-704909b924d9

result, different first party: 
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14,
c5564407-7930-46c1-a37e-f1144b78e7ec,
2f8f7e17-f84b-4431-b146-693b0fd9321f,
36348409-e50d-4651-bda3-4959f87f3001,
3c437474-8fee-4456-93f1-bc16a36d47d2

result, different first party: 
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d,
7549b7b2-c691-4ec0-853b-002bc7356afd,
20a4ff98-e9e0-46fc-b6fe-e284015063f6,
f4f8644c-fd35-4941-8573-0f784f481de5,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392

result, different first party: 
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5,
11450af2-985c-44a8-9472-b73dc6ee5027,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce,
435bef94-82e0-4fa8-8fea-117f9e16b6a7

result, different first party: 
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
BroadcastChannel
A BroadcastChannel is designed to send messages between tabs. In some browsers it can be used for cross-site communication and tracking.
              
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: 
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: 
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: 
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: 
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c,
b4870a62-d8c7-4aa3-b869-a4b56ada1280,
49049c26-be88-49c3-aacd-606f570a5052,
f5068b02-e5d5-46da-b936-704909b924d9

result, different first party: 
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14,
c5564407-7930-46c1-a37e-f1144b78e7ec,
2f8f7e17-f84b-4431-b146-693b0fd9321f,
36348409-e50d-4651-bda3-4959f87f3001,
3c437474-8fee-4456-93f1-bc16a36d47d2

result, different first party: 
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d,
7549b7b2-c691-4ec0-853b-002bc7356afd,
20a4ff98-e9e0-46fc-b6fe-e284015063f6,
f4f8644c-fd35-4941-8573-0f784f481de5,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: 
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: 
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5,
11450af2-985c-44a8-9472-b73dc6ee5027,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce,
435bef94-82e0-4fa8-8fea-117f9e16b6a7

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: 
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: 
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
CacheStorage
The Cache API is a content storage mechanism originally introduced to support ServiceWorkers. If the same Cache object is accessible to multiple websites, it can be abused to track users.
              
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: 
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: 
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: 
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
cookie (HTTP)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
              
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_http,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_http,
409ba143-3756-4f1b-ae02-00cf293ba63f_http,
c9708147-e276-4272-83fd-b1d199e502bd_http,
302b0701-b3ea-4cfa-9137-acf825e86529_http

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748_http,
b9ab569e-b293-4a12-be90-a0ed912621d1_http,
4667878f-16a5-4ecd-9e94-855e7e60726f_http,
1c48fec6-4615-4891-ae9a-669a540891f0_http

result, different first party: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf_http,
3548065b-9016-4d4b-b100-6ed874da1441_http,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_http,
15610b24-812c-4f95-a6ec-f725f40db44e_http,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_http

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639_http,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_http,
45cebc9a-6449-461a-9eaf-55fe8533da65_http,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_http,
5ed1f834-f5f0-4741-9db0-b54a51473811_http

result, different first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639_http,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_http,
45cebc9a-6449-461a-9eaf-55fe8533da65_http,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_http,
5ed1f834-f5f0-4741-9db0-b54a51473811_http

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a_http,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c_http,
b4870a62-d8c7-4aa3-b869-a4b56ada1280_http,
49049c26-be88-49c3-aacd-606f570a5052_http,
f5068b02-e5d5-46da-b936-704909b924d9_http

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14_http,
c5564407-7930-46c1-a37e-f1144b78e7ec_http,
2f8f7e17-f84b-4431-b146-693b0fd9321f_http,
36348409-e50d-4651-bda3-4959f87f3001_http,
3c437474-8fee-4456-93f1-bc16a36d47d2_http

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d_http,
7549b7b2-c691-4ec0-853b-002bc7356afd_http,
20a4ff98-e9e0-46fc-b6fe-e284015063f6_http,
f4f8644c-fd35-4941-8573-0f784f481de5_http,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392_http

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61_http,
2d6a5964-5158-4308-a47c-d338fc246ce0_http,
820df721-3242-48ee-839b-39229099fc04_http,
187af9d9-f96d-473d-a956-a5d2ff600513_http,
dc205c47-3eeb-4d49-8103-0fc967659706_http

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f_http,
a607723a-0d84-4334-958b-2c313172a3ba_http,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_http,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_http,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_http

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e_http,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5_http,
11450af2-985c-44a8-9472-b73dc6ee5027_http,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce_http,
435bef94-82e0-4fa8-8fea-117f9e16b6a7_http

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_http,
b8608586-7364-4679-a64d-3826b8686898_http,
a82a08c9-d035-4122-b83c-42b933931544_http,
3b7b0f8a-22d5-41b9-8443-475da21a220e_http,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_http

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_http,
42131e6f-5e91-454b-905d-4683d1f89cc0_http,
124a771f-06af-4c5d-9669-4020fbcbe2ec_http,
45b6e96f-1181-4133-ac15-69d0a3719c1a_http,
438d0770-7624-4fa5-8c32-1623e842a289_http

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
cookie (JS)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
              
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_js,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_js,
409ba143-3756-4f1b-ae02-00cf293ba63f_js,
c9708147-e276-4272-83fd-b1d199e502bd_js,
302b0701-b3ea-4cfa-9137-acf825e86529_js

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748_js,
b9ab569e-b293-4a12-be90-a0ed912621d1_js,
4667878f-16a5-4ecd-9e94-855e7e60726f_js,
1c48fec6-4615-4891-ae9a-669a540891f0_js

result, different first party: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf_js,
3548065b-9016-4d4b-b100-6ed874da1441_js,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_js,
15610b24-812c-4f95-a6ec-f725f40db44e_js,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_js

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639_js,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_js,
45cebc9a-6449-461a-9eaf-55fe8533da65_js,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_js,
5ed1f834-f5f0-4741-9db0-b54a51473811_js

result, different first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639_js,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_js,
45cebc9a-6449-461a-9eaf-55fe8533da65_js,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_js,
5ed1f834-f5f0-4741-9db0-b54a51473811_js

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a_js,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c_js,
b4870a62-d8c7-4aa3-b869-a4b56ada1280_js,
49049c26-be88-49c3-aacd-606f570a5052_js,
f5068b02-e5d5-46da-b936-704909b924d9_js

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14_js,
c5564407-7930-46c1-a37e-f1144b78e7ec_js,
2f8f7e17-f84b-4431-b146-693b0fd9321f_js,
36348409-e50d-4651-bda3-4959f87f3001_js,
3c437474-8fee-4456-93f1-bc16a36d47d2_js

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d_js,
7549b7b2-c691-4ec0-853b-002bc7356afd_js,
20a4ff98-e9e0-46fc-b6fe-e284015063f6_js,
f4f8644c-fd35-4941-8573-0f784f481de5_js,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392_js

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61_js,
2d6a5964-5158-4308-a47c-d338fc246ce0_js,
820df721-3242-48ee-839b-39229099fc04_js,
187af9d9-f96d-473d-a956-a5d2ff600513_js,
dc205c47-3eeb-4d49-8103-0fc967659706_js

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f_js,
a607723a-0d84-4334-958b-2c313172a3ba_js,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_js,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_js,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_js

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e_js,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5_js,
11450af2-985c-44a8-9472-b73dc6ee5027_js,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce_js,
435bef94-82e0-4fa8-8fea-117f9e16b6a7_js

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_js,
b8608586-7364-4679-a64d-3826b8686898_js,
a82a08c9-d035-4122-b83c-42b933931544_js,
3b7b0f8a-22d5-41b9-8443-475da21a220e_js,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_js

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_js,
42131e6f-5e91-454b-905d-4683d1f89cc0_js,
124a771f-06af-4c5d-9669-4020fbcbe2ec_js,
45b6e96f-1181-4133-ac15-69d0a3719c1a_js,
438d0770-7624-4fa5-8c32-1623e842a289_js

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
CookieStore
The Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.
              
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
CSS cache
CSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.
              
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_8678566111746515,
fake_952453890135784,
fake_10467023234618278,
fake_30794822562798263,
fake_22608342466678444

result, different first party: 
fake_6926912356872235,
fake_17104548136226572,
fake_5233253064629657,
fake_36259568113903495,
fake_46193580167190285

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_9970904628161013,
fake_9925417056359969,
fake_21043928204223739,
fake_5255796261853249

result, different first party: 
fake_722915332083929,
fake_15220641160195125,
fake_5684131691214869,
fake_7425788095966877

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_701520617439408,
fake_9592780159848653,
fake_12581708990183627,
fake_227454626276262,
fake_9142192550244868

result, different first party: 
fake_871532933904084,
fake_8909741670075801,
fake_19385632885312543,
fake_07318030498103045,
fake_3004412618239647

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_6859301540881,
fake_69111341437601,
fake_33952663041443576,
fake_8382875136817705,
fake_8859943182501229

result, different first party: 
fake_34671309052532306,
fake_3049406136361834,
fake_8804397331829301,
fake_4910574289148324,
fake_3870400538657297

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_6682914268318276,
fake_23515075380228345,
fake_5439086783566336,
fake_9262171831190795,
fake_10154425764297637

result, different first party: 
fake_9563001212371116,
fake_35915499957946473,
fake_9664681995281359,
fake_04812273249340526,
fake_2281738997302356

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_8934348606012921,
fake_714206319977662,
fake_20247089115232475,
fake_238040723821346,
fake_39527274532198486

result, different first party: 
fake_9138574779683604,
fake_9022312027142181,
fake_9220211404245222,
fake_33156367572972467,
fake_02704247261864534

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_6645263590760535,
fake_22887785302632757,
fake_020634861682654382,
fake_5685840966676194,
fake_17250229249119742

result, different first party: 
fake_5671629999242624,
fake_115598671918417,
fake_7534021865688829,
fake_3666757994360337,
fake_6597150089617336

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_8907866272449696,
fake_069137141299213,
fake_10724547655056704,
fake_799996778952127,
fake_5032858290024977

result, different first party: 
fake_39609814453459435,
fake_1316812638078404,
fake_09576470786987068,
fake_6247831888154187,
fake_6283772363024986

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_8231790720930534,
fake_6478716420362403,
fake_5991322889150483,
fake_12915695098639368,
fake_641324949519114

result, different first party: 
fake_10583107300313532,
fake_9040974731230464,
fake_635186073904932,
fake_4374438252052406,
fake_26961186984320906

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_10111735383560161,
fake_8563916608544744,
fake_7642349927909833,
fake_7978638562529079,
fake_73436358367003

result, different first party: 
fake_8949840371086681,
fake_46734775081165947,
fake_18285564123293385,
fake_18781932065652285,
fake_6554972948856377

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_5258657679741365,
fake_7547431962782956,
fake_652559497307516,
fake_6477183286049182,
fake_20625547635933517

result, different first party: 
fake_33113153627697156,
fake_9351102079409408,
fake_7175443526927408,
fake_08058444989232072,
fake_21330727168491892

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same first party: 
fake_3598862169325485,
fake_5297415624399859,
fake_2684673574313181,
fake_7406956924743309,
fake_5145161275483361

result, different first party: 
fake_8667821312626902,
fake_04205081745619532,
fake_20599247956073463,
fake_03543917082920678,
fake_6410783522113115

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
favicon cache
A favicon is an icon that represents a website, typically shown in browser tab and bookmarks menu. If the favicon cache is not partitioned, it can be used to track users across websites.
              
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1

result, different first party: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same first party: 2, 2, 2, 2, 2

result, different first party: 3, 3, 3, 3, 3

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
fetch cache
When a resource is received via the Fetch API, it is frequently cached. That cache can potentially be abused for cross-site tracking.
              
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1

result, different first party: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
font cache
Web fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.
              
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1

result, different first party: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 2, 2, 2, 2, 2

result, different first party: 3, 3, 3, 3, 3

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
getDirectory
navigator.storage.getDirectory exposes a location for storing files to web content. In some cases, these files may be shared across tabs.
              
Passed
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: , , , , 

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
H1 connection
HTTP/1.x are the classic web connection protocols. If these connections are re-used across websites, they can be used to track users.
              
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c,
b4870a62-d8c7-4aa3-b869-a4b56ada1280,
49049c26-be88-49c3-aacd-606f570a5052,
f5068b02-e5d5-46da-b936-704909b924d9

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14,
c5564407-7930-46c1-a37e-f1144b78e7ec,
2f8f7e17-f84b-4431-b146-693b0fd9321f,
36348409-e50d-4651-bda3-4959f87f3001,
3c437474-8fee-4456-93f1-bc16a36d47d2

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d,
7549b7b2-c691-4ec0-853b-002bc7356afd,
20a4ff98-e9e0-46fc-b6fe-e284015063f6,
f4f8644c-fd35-4941-8573-0f784f481de5,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5,
11450af2-985c-44a8-9472-b73dc6ee5027,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce,
435bef94-82e0-4fa8-8fea-117f9e16b6a7

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
H2 connection
HTTP/2 is a web connection protocol introduced in 2015. Some browsers re-use HTTP/2 connections across websites and can thus be used to track users.
              
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c,
b4870a62-d8c7-4aa3-b869-a4b56ada1280,
49049c26-be88-49c3-aacd-606f570a5052,
f5068b02-e5d5-46da-b936-704909b924d9

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14,
c5564407-7930-46c1-a37e-f1144b78e7ec,
2f8f7e17-f84b-4431-b146-693b0fd9321f,
36348409-e50d-4651-bda3-4959f87f3001,
3c437474-8fee-4456-93f1-bc16a36d47d2

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d,
7549b7b2-c691-4ec0-853b-002bc7356afd,
20a4ff98-e9e0-46fc-b6fe-e284015063f6,
f4f8644c-fd35-4941-8573-0f784f481de5,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5,
11450af2-985c-44a8-9472-b73dc6ee5027,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce,
435bef94-82e0-4fa8-8fea-117f9e16b6a7

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }

read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
H3 connection
HTTP/3 is a new standard HTTP connection protocol, still in draft but widely supported by browsers. If it is not partitioned, it can be used to track users across websites.
              
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: 
015c45f96577c569134176e395d319db,
7a35c3467b42cd616278daea55216ddf,
d844f76ca440566a3e66992f6366af80,
8d12848b98598f60b599ec36008f65ac,
5119b332d5b48f05e6d75c169f779a28

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: , , , 

result, different first party: , , , 

unsupported: true, true, true, true

passed: undefined

test failed: false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: 
e9ca48abef2be6b631a7a1e75ae3b136,
3f4413df183a3906cfc4edd9228f9dee,
a2240cbef6e25a7bb4632c52dea38e2d,
0b772759cc14dc1ee6578aa66226aa16,
d18d2d049d7ff269c71f31d736c3414c

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: 
86648945b73a914f4e0278db1d1f3a6e,
b5a5350cd9a74907fc8582c6c62e2621,
76f6fce8fad41d1ce49381da6cb44b89,
d8a2c932f54c1bb0df8cb1300e2b6471,
ac1e0649b2551407f7cccd03c47ab86c

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: 
3207d60dde72328bf32c9294af3ee6b2,
8c4a38e2067f49c7f4db1d44ce515544,
d8e926c73ac55afc0d2459d0777d56ef,
2b196b0a05caa897213fea39380f3569,
e3400c451bf8f9d1a25fd15d21b9cb50

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: 
156d2b5c1fb751fc9de5314a7eaa8469,
853a5785cecf0f94c6960f47f5d2e553,
b3a08d9edfc9a9cbf14ccc8e82ef2ef7,
38ef16aa5f93fcea54f6a68171ec81ff,
eae5aadb31cfd04cdeaa35e2a459d0df

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: 
7dd51c777a6c8bf878857b4f0a518016,
9ebe2d7cd9281caf0b285bc27978e4e7,
062a0618a6ec96b4f65db4ac2baeff3e,
a79ba0f3cc390fc0d90b311effa3b07c,
04fe7e2c3819fef05ef3fda87484df05

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: 
0a71d5fdafb8a6b6551daffa84f456ec,
813483164e7d555ea0d1bcdf168e5b87,
0cb071d6fea4d1dc2216cb8f96e18d88,
dbbe402247c59c3967514d3d719b6082,
e0f79890f92628590b8d06342ea29af8

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: 
815dfe0e3c15289ba46d94b268f1304a,
f225dd8c9e649b9de925d0849b9b06ac,
,
96ec95b79772abcd0d282ad9512dfb29,
413e85b642df953b34e40e500a351358

result, different first party: 
7dae5f2bef7735ae7de986f18e69319a,
c6ef5c5bee954b9c502a1c0223519876,
c8bfc349fa23465c2b4d1b97e0ee9bab,
c532d6f303f144f0c2522a580e6007f1,
0ef174ad13537d8bca0b6bbdac0b8e3d

unsupported: false, false, true, false, false

passed: true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: , , , , 

result, different first party: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: 
4cd53a42c2d649d62dac1b1254a547fd,
3509641bc8175017a8622f1c9aeea0d4,
17a6b45159d5f9baf4b34de81e9aa1de,
c5daa0b50f61426a9abb6b0210538427,
fc47a6e6e46d9a6d1d30ff3d759c6ad9

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }

result, same first party: 
9ac0c2588da64157b3c2bdf14a4ef2b9,
f7022dc42eadcd790a8d0eaca99acc3a,
caca3105fbec1d2eb7c598db4affdef6,
533a64555c0a1535446c5d365bce1c87,
0bd81bd5bdbcd6b82f407152c94eb90b

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
HSTS cache
The HTTP Strict-Transport-Security response header allows a website to signal that it should only be accessed via HTTPS. The browser remembers this directive in a database, but if this database is not partitioned, then it can be used to track users across websites."
              
Passed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: Used http, Used http, Used http, Used http, Used http

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: null

read: null

result, same first party: , , , 

result, different first party: 
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected

unsupported: , , , 

passed: true, true, true, true

test failed: false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: Used http, Used http, Used http, Used http, Used http

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: null

read: null

result, same first party: , , , , 

result, different first party: 
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected

unsupported: , , , , 

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: null

read: null

result, same first party: , , , , 

result, different first party: 
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected

unsupported: , , , , 

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: Used http, Used http, Used http, Used http, Used http

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: null

read: null

result, same first party: , , , , 

result, different first party: 
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected

unsupported: , , , , 

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
HSTS cache (fetch)
The HTTP Strict-Transport-Security response header allows a website to signal that it should only be accessed via HTTPS. The browser remembers this directive in a database, but if this database is not partitioned, then it can be used to track users across websites."
              
Passed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: Used http, Used http, Used http, Used http, Used http

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: null

read: null

result, same first party: , , , 

result, different first party: 
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected

unsupported: , , , 

passed: true, true, true, true

test failed: false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: Used http, Used http, Used http, Used http, Used http

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: null

read: null

result, same first party: , , , , 

result, different first party: 
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected

unsupported: , , , , 

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: null

read: null

result, same first party: , , , , 

result, different first party: 
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected

unsupported: , , , , 

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: null

read: null

result, same first party: , , , , 

result, different first party: 
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected,
HTTPS used by default; no HSTS cache issue expected

unsupported: , , , , 

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: set HSTS flag

read: read HSTS flag

result, same first party: not tested, not tested, not tested, not tested, not tested

result, different first party: 
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
iframe cache
An iframe is an element in a web page than allows websites to embed a second web page. Caching of this web page could be abused for cross-site tracking.
              
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1

result, different first party: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
image cache
Caching of images in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.
              
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1

result, different first party: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 2, 2, 2, 2, 2

result, different first party: 3, 3, 3, 3, 3

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
indexedDB
The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
              
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c,
b4870a62-d8c7-4aa3-b869-a4b56ada1280,
49049c26-be88-49c3-aacd-606f570a5052,
f5068b02-e5d5-46da-b936-704909b924d9

result, different first party: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14,
c5564407-7930-46c1-a37e-f1144b78e7ec,
2f8f7e17-f84b-4431-b146-693b0fd9321f,
36348409-e50d-4651-bda3-4959f87f3001,
3c437474-8fee-4456-93f1-bc16a36d47d2

result, different first party: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d,
7549b7b2-c691-4ec0-853b-002bc7356afd,
20a4ff98-e9e0-46fc-b6fe-e284015063f6,
f4f8644c-fd35-4941-8573-0f784f481de5,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5,
11450af2-985c-44a8-9472-b73dc6ee5027,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce,
435bef94-82e0-4fa8-8fea-117f9e16b6a7

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
localStorage
The localStorage API gives websites access to a key-value database that will remain available across visits. If the localStorage API is not partitioned or blocked, it can also be used to track users across websites.
              
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c,
b4870a62-d8c7-4aa3-b869-a4b56ada1280,
49049c26-be88-49c3-aacd-606f570a5052,
f5068b02-e5d5-46da-b936-704909b924d9

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14,
c5564407-7930-46c1-a37e-f1144b78e7ec,
2f8f7e17-f84b-4431-b146-693b0fd9321f,
36348409-e50d-4651-bda3-4959f87f3001,
3c437474-8fee-4456-93f1-bc16a36d47d2

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d,
7549b7b2-c691-4ec0-853b-002bc7356afd,
20a4ff98-e9e0-46fc-b6fe-e284015063f6,
f4f8644c-fd35-4941-8573-0f784f481de5,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5,
11450af2-985c-44a8-9472-b73dc6ee5027,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce,
435bef94-82e0-4fa8-8fea-117f9e16b6a7

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
locks
navigator.locks (only supported in some browsers) allows scripts on multiple tabs to coordinate. If this API is not partitioned, it can be used for cross-site tracking.
              
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: 
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: 
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: 
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: 
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c,
b4870a62-d8c7-4aa3-b869-a4b56ada1280,
49049c26-be88-49c3-aacd-606f570a5052,
f5068b02-e5d5-46da-b936-704909b924d9

result, different first party: 
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14,
c5564407-7930-46c1-a37e-f1144b78e7ec,
2f8f7e17-f84b-4431-b146-693b0fd9321f,
36348409-e50d-4651-bda3-4959f87f3001,
3c437474-8fee-4456-93f1-bc16a36d47d2

result, different first party: 
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d,
7549b7b2-c691-4ec0-853b-002bc7356afd,
20a4ff98-e9e0-46fc-b6fe-e284015063f6,
f4f8644c-fd35-4941-8573-0f784f481de5,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392

result, different first party: 
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: 
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: 
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5,
11450af2-985c-44a8-9472-b73dc6ee5027,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce,
435bef94-82e0-4fa8-8fea-117f9e16b6a7

result, different first party: 
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: 
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: 
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
prefetch cache
A <link rel='prefetch'...> suggests to browsers they should fetch a resource ahead of time and cache it. But if browsers don't partition this cache, it can be used to track users across websites.
              
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 1, 1, 1, 1

result, different first party: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different first party: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different first party: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different first party: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different first party: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
ServiceWorker
The ServiceWorker API allows websites to run code in the background and store content in the browser for offline use. If a ServiceWorker can be accessed from multiple websites, it can be abused to track users across sites.
              
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: 
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: 
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

result, different first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

result, different first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

result, different first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: , , , , 

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Unsupported
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

result, different first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
SharedWorker
The SharedWorker API allows scripts from multiple tabs to share a background thread of computation. If SharedWorker is not partitioned, then it can be abused to shared data between websites in your browser.
              
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: 
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: 
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c,
b4870a62-d8c7-4aa3-b869-a4b56ada1280,
49049c26-be88-49c3-aacd-606f570a5052,
f5068b02-e5d5-46da-b936-704909b924d9

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14,
c5564407-7930-46c1-a37e-f1144b78e7ec,
2f8f7e17-f84b-4431-b146-693b0fd9321f,
36348409-e50d-4651-bda3-4959f87f3001,
3c437474-8fee-4456-93f1-bc16a36d47d2

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d,
7549b7b2-c691-4ec0-853b-002bc7356afd,
20a4ff98-e9e0-46fc-b6fe-e284015063f6,
f4f8644c-fd35-4941-8573-0f784f481de5,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5,
11450af2-985c-44a8-9472-b73dc6ee5027,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce,
435bef94-82e0-4fa8-8fea-117f9e16b6a7

result, different first party: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
TLS Session ID
The TLS protocol is used by HTTPS to make connections secure. If the browser were to re-use a TLS session, then the session ID could be used to track users across websites.
              
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
6f863371b830f22672c25471121ddd7589dddbb27e116cb8fbd5e5c1e2faa277,
477f60c4043b94ab2f1d9f765b674423ad6075e552b8c55069d562ec5b86edd2,
0fd55e73ddcc856e2cd3bdf1f648f6435d4fd0edef7a13836a3df9fefbc45ad4,
a294453e64abdbe69c2a4b97c699922341c552e58f03dd9d5b6f3bbdad4b21b0,
5d3b7ee5ec6319f70d5e02ed7eac55e057eb5cbe41add50204aec157fee1f819

result, different first party: 
1af4f1139a799c1186f19bdc970e79abf1feaf7c33447bf1e247dac0c2b5c468,
7c638f37babd6016273acd785a495d8c23b00d28167c77ea454fc962a9d47999,
ff2043c86f0df7c637d22d789e0d4ffe31538e04f0f0ba27e24607dbfa5a37ef,
d6f2584b30f6403aed342b4d5d5039a234483105d4aafad526e2ae35bb329d6a,
d787a58735de26d2b696a410617045937e2285b82de26c439f73b5e7a0390cf7

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
b60e33df218feed33f4fbd908f92f5f6fec48203dd4cd9b4cc1f32a685fa9501,
22d13af33d57e2c654203b51f994bbf4179b403e52832123d3e04f90c2a571fe,
39b8cbae394362cc91a7440e27f41c638d9f95b35fd28a1c2bd426d4c0191576,
54de89be0edd2b9e9bb99fe0bced0035cbc212efc5b76d67d422f1c44dabfb0f

result, different first party: 
e41ae295df72710bdc9fe350795bed08116f827e691cf78b87ab874896084488,
66a668ec5c4dc36b6153e0be79fcb09a64b1a32563abce99cac97517346ba46c,
ccba3bde28fab9886711955dc2b52dffc246cb8f57fd07360dba1700d78e071e,
ccbc848843d8fd23529615fc7ce064ea506becbc105a807e607571179dd020a0

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
f1d7e2f9da68789ff95282b74a64dffb305cf56fb41a7fe7df9b19e8921a1ce9,
0cbdfcd19d202835ec99e04dc5869d9631d9f4ef72009b1bc4ed77e0011aaf50,
b5d7118029c546f6b8bf28456a7524481e09307aee662c4c2317679c38e7ddad,
961cfcdd83edc7e29ed1fe52cc15d90d41eddd319807eae4445d4ee9cc8e076d,
cc5ddc0b9fdea4fc8d374f040c3fbbd17b9bf62abc38a88eb45a819be6a6fc24

result, different first party: 
ddff791af28b53d93622956708780515dbfb5c7aa256a72a85276160f259648d,
c98ced67e176b0c0651bed8fdb35e8a39ea97e4da8082fbc2edaa55c8db2285d,
2fe9411e8c64587fbbc8c12114eca38b6704fdaed20a9444370132b079baec5a,
7a2ed904ad9c2e33801e3b4fe7fc3291c411d0cb05d854564f146e9061dfa582,
24ccc961ea77dc0d43ad1b462fbd9b85e8d99aabdd3c35fae9090eaa78b185c7

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
6bea3661256b2b70dfc9f418e4f2238a24afde151bc3fe041f74c1bd218fd965,
f0352d2943ae3e739a65efc674bcc672541836a4410b2808d984c44debf808ce,
774177d9d79cf16eecbdd3f6c8e6ad23201515225253241db6920c326de1f013,
1a452906cbdb4e772f3e504838ea325c23f13a86a8fd9044ebd15cf0d227a1d2,
b0224a6523bf3337b31c5143d9265e254bc9e46eaf1384fc8dad9688561a21a6

result, different first party: 
7abb3259fce1c8d1833c364ed6fce563b6cfcd09700f62199ba99406901e4039,
2ef0f4c74d894e352acb7dd2854bcfb8586b37403b359a971c11f89c672f3edb,
8e600c51fbe7d87659a69e673d887dc55a3f60902da9415cff375d33eb325daa,
cd80e31705e55b08f099edc03f9f3e4bbc07c641b6f9535029ef4941ca737b31,
4bbc900598f09e0f791e2db20671c4b9861a695aa3a95cba2c71c073b8070c32

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
53068fa1ee35effd3558bf7fcb1cffd771ce12a3b6ebe698950dc21c24c29a07,
577c462e9a1064ea6345028f5262c423ffc1288a6588dc168f8a87f2f0dc2c1e,
3d6027e701c241ff4e54482a7a064087c6544421cdd9b8a9a4799719d1df3600,
6ee9976d8e9c9474b49830fc164af85a60cbc2be7e085e6c0617837af87fb632,
28fa06fd96d9b216e3499206654a4f5526c9d0953d9679c7595136b108fa214a

result, different first party: 
ce3d528f01da16a00a031e2800fa0e087dfe5332e477ad00f19df6308204d804,
5932579785fc2c2f7f4849410bff8234d5d46884e9a4822ebabd32583a02a8f7,
c18afbea9a1e9733204d103000a2cc4e37ce32f050665755d685fc561e79d6ac,
068be3115d9e98546de07b68c0b49fca614d72cd791d4b75a47fcbb11f743ea0,
1b19da51b8c2ca50d4b61930ebc478e4b7bcb80a61143865e73ce9baac5e1ca8

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
e2c1e8e26932cc9fd606d4d0ed09ada16d363fdb7c473ad45c8b390d766776eb,
4e8b49b8dcfc3a173264d80239aaf9092820e63194a69384d99de5e255ffeae9,
238f11841189d3460d644940f7f253c4e4555d68c260366e46501ff51ed05d2b,
9821e6f4219473e26720d1ee8046fbae0e33852e7f3a7ef28326f012f08c49eb,
fec89ddf9512cc73a29e471a7754c4364c949f2400fda86e5a9d8c79d0a72b09

result, different first party: 
ccee9c18d770c13397d8254ef20adfaabc2aa680f38c9c94f2285c3ecdf64ec5,
bb8cc2f8503f316a15e709c216f9114027795ff3cf33e79cae55bee70e7e7511,
5735cffb1bc2fe33349baa6d80f01e1a149f104dbc49ed8c877c6c449c8845d0,
7adc97cad78549a45a9fa6a0187dda8507145ca19bd3448e5189fe1c3d170cdb,
61fc27712ad91c28c0a0050e4783a0cf8632543dc42651359f48df1ee2b2af68

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
d108e01f28cb4340e7bcd3fdad6325a03bb6e7353df8f17d91af2d4eae973a9f,
f3551da26d77ec67b1ec53a06edf2098ca54ddeafb8cb4351fcf4a7af7f02001,
25523a88606144116ad4722eaf4d8835bccc5348e07a99539ea3ae5d7450036b,
c1b9269dc1a209264ab4a053e8fd5074d3d6083305482230c38eb8196f791396,
da59508d7498b6dfe9b33821242097adf9bc8a32887708fc99f762de5aa42395

result, different first party: 
180650249bc7368edbe96c87ee2d697cf86c9c48176398bd1cbae0f99a7f8a1a,
71c3daa7e989a5d5f61991f6116a936e9a5505e4db4d17b980da5753ab32ebd8,
2a5ab9c9745f6e5f92312479c384203f46c006de5b6bd7e450936957664267a9,
04f6640ae66988695575fbfa2fca8e5b80c19d7ba68a0812b05b96cd835b50de,
3d9cd59ee8f3048bd466e33defa78bf3a6b6fbe6b3df514f78dbf00b23ac25f2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
0d354b8f1a3634b5c944a26e5dcdfa0d03ed6bf9ff777e20fa1708917140e71c,
564920ea3aea88e7c356f8d2bf3b9db4ba9e2fb0dbb7844c13e5ff38c7bd5344,
5196b1531b750952625134fa2a8b88868da7a56966486522a15913fd53491a5c,
e81b97008d3331462155f313fcfadb8825f67f15216734a02efe41abcf072350,
e83ea37543cf9e921ad773dec38b49a0e5df7c0b64a65cbf868d3086d9161a18

result, different first party: 
c26a170d752fbc6007fc299025e38144aca9b18ee35054208b94e24aa498fe28,
58fcc96dfcf13476a510d8a302973364a617b4d0bd1393d0b48eb67e0c6efa9a,
cbdd1f4006a8220e0a2e1d8357e310dec7cd493bda1e6863ed9027a8a3b1e4e4,
af69324264a0a5e4c5b54f0cde2e0ff0575802f5c080d67943bec8a8e07fe954,
b77da8bfff7c61c3b4f4d2aad1c657f08aca21116187a1564f296cf5afa657c7

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
38dabc70884524036181ee2c1b8a6599b94a2c8222a51d19740fb6ad30f2cbe6,
60c778274d176ea9ca1b2c3c7a1d2eb925655d4d05b55ae7622ce9af338a86c3,
b86da8545d14cce8533242635976505a7f100b8ac675df3d248a0d9ef031a978,
6b9d7613711a6520d4740c06360e31c2ef02dd6f037ca8453e366f7cd7b6baa9,
119ff27685e7258a0f900127ad28a9fc30f3b780bb8df1d30d5ef48b721d7eda

result, different first party: 
c69aef86389cd42885d2eba73f03fdc41d4641a7d279da3abe536ba4cf3161ce,
2cfb6f636940a7fd974ab7a02fd58c175584fe3278ded7f4a61009ffb2848e2c,
e8daadf4c914e7712a755d72128c91b1e6765d71e38800e679565798d65ed803,
7c97123aad8bdef0838aef8da9e406540f1a68950846d7beaeddfd7267b11816,
4a5b1a436f85cc367e32623b50bbfd9c5bee83517116b17650bf3cb4c49ff6a9

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
da12843b7e5ad8e3e5bdf5a757f00ddf31323207f1631b0b9188ce3041918a5a,
4a00257f5a3f8d410f588958c1d9c6c60d04576c9ae40c90b4081b5f012e7bb9,
68c977b5600a3bd46b536509e47e7e42436a7c9f01e14913181ab5ac6484926f,
511f281d6e34643b344e3918c23b5b5ec2f79c181ed6ce6c78aecc41a63df4e0,
f1174f9750cb1a5a58565d5f727ddcfaa8a4e987471584707066bae9ba405e3d

result, different first party: 
dc710a84541a25b4f83433f0a7e40250e7f24ae1253c68b4d1d1928ec78f57ce,
3692783ae8a5bdec964c76f06eba4eb13e504b7b34be8efbedff8ade35abbe62,
18804221bb5f915335e21d2fd1aaace5ac62eab0a6ea03d1e1a4807c833f4e87,
7914843b9e28af36e2b0745339581eb3a32257ce5155305f8cded6c6571039bd,
ce1086e174ce941228a78b396ef7dd5e718883b4fca9f167e009699398cb4e1a

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
e4db3ec620dcacd2a4f0c303b9a78922b16169c4f7c690e51d19fd99630065f3,
73c18ebd04834276629f70cbef7156fd73cced8889639b4f0688b85be3d0fe69,
dcd864a351ea307d3ad5ee4b051b0f44c722a63fdefe8b678e430a34ca885e62,
2afbe1e7a0a213ba64f98f5d75bb3a1300e2c7bdbafcc44c05a1129b0b7f79a0,
e169aadcec4732969d07663b8e36d33485967e00bbfd4f7d451220282a7c83f4

result, different first party: 
5d7f1ee70bfabf430521757b6651601e9ae17cd6f7320b1f9811b00445178501,
0387708c90d6952d73ccdd4ac537551566ebc77de24cd3cdfa2e780fab7b9406,
b045010d18546fdf659608bd7481091cfb56055ed4ee87bed7597a0243552dd1,
a715d692b7f26a201b9023e36555264b36a81d65a195bcf12f062603e9471fb9,
8ac59bdd8739b378d135ff44f8b714c846675e5df0185e1c0bd6f57a2801954f

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }

result, same first party: 
4a072c33dfb01df7b027c644569f3c4ade8888fc3ace39e7c9f4314972c2d820,
78abc7945247e371fce2c71e5f97f530f9dceac75b00f59bb145f84c3225b3ac,
f430f8d4fad5a14dc97f952d6fa0d8a616fbbae06e2865bb78762133479e01ea,
f4ba184032532b98e3e8e31fb2df53d7738dd213e47d16491cd2ca799a0fdd51,
fbc684ac082a93394491ba2b689af0efeae8913580925b97132cf1ab82075ee8

result, different first party: 
30d4212e3c7db3e213f7d5e420eac3a7d15925ea5aa6a493af9ba0f4625321f8,
4f6b91ea7b944155f934d65335b2ddb9527bad979c690505cd0326f295c805c8,
39fba01c2de8fa7a89814ea8ca6f7b0de17674feff3f98d231feffb2f22d72af,
b4bb4e6db16d3341d52ff706b6b25e9ded7e63a2b1bd59ec027577a46f92c83d,
acdc25a7b26beda60118d1d8219766cfad3bde88181f330ae828acb4fe4f685b

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Web SQL Database
The Web SQL Database is a deprecated web API for storing data in an SQL database.
              
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false

passed: undefined

test failed: true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated

result, different first party: 
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
Passed
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different first party: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: false, false, false, false, false

passed: undefined

test failed: true, true, true, true, true
XMLHttpRequest cache
Similar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.
              
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1

result, different first party: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same first party: 1, 1, 1, 1, 1

result, different first party: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Navigation testsWhich browsers prevent websites from sharing tracking data when you click on a link?
When you click a hyperlink to navigate your browser from one site to another, certain browser APIs allow the first site to communicate to the second site. These privacy vulnerabilities can be fixed by introducing new limits on how much data is transfered between sites.',
        
document.referrer
The Referer [sic] request header is a mechanism used by browsers to let a website know where the user is visiting from. This header is inherently tracking users across websites. In recent times, browsers have switched to a policy of trimming a referrer to convey less tracking information, but Referer continues to convey cross-site tracking data by default.
              
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false

passed: false, false, false, false

test failed: false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

result, different first party: 
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
sessionStorage
The sessionStorage API is similar to the localStorage API, but it does not persist across tabs or across browser sessions. Nonetheless, it can be used to track users if they navigate from one website to another. This tracking can be thwarted by partitioning sessionStorage between websites.
              
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
230d0662-cf1b-4545-b3d6-f79a5fa51fce,
409ba143-3756-4f1b-ae02-00cf293ba63f,
c9708147-e276-4272-83fd-b1d199e502bd,
302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
c5366d00-9adf-4038-a40e-30fa84214748,
b9ab569e-b293-4a12-be90-a0ed912621d1,
4667878f-16a5-4ecd-9e94-855e7e60726f,
1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
10d65996-b480-4f3d-ba1a-82994148cebf,
3548065b-9016-4d4b-b100-6ed874da1441,
b2a2b327-6c81-459d-9d8a-27cf71cd116d,
15610b24-812c-4f95-a6ec-f725f40db44e,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
eebe4c45-6842-4d19-ac58-8ba38a062639,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
45cebc9a-6449-461a-9eaf-55fe8533da65,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
5378069e-62e6-4c65-a4d7-c26e7103a34a,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c,
b4870a62-d8c7-4aa3-b869-a4b56ada1280,
49049c26-be88-49c3-aacd-606f570a5052,
f5068b02-e5d5-46da-b936-704909b924d9

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14,
c5564407-7930-46c1-a37e-f1144b78e7ec,
2f8f7e17-f84b-4431-b146-693b0fd9321f,
36348409-e50d-4651-bda3-4959f87f3001,
3c437474-8fee-4456-93f1-bc16a36d47d2

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d,
7549b7b2-c691-4ec0-853b-002bc7356afd,
20a4ff98-e9e0-46fc-b6fe-e284015063f6,
f4f8644c-fd35-4941-8573-0f784f481de5,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
1434311d-0f56-422e-84f7-59f56932dc61,
2d6a5964-5158-4308-a47c-d338fc246ce0,
820df721-3242-48ee-839b-39229099fc04,
187af9d9-f96d-473d-a956-a5d2ff600513,
dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
effad01a-1965-41dc-87ed-eec28f291b5f,
a607723a-0d84-4334-958b-2c313172a3ba,
f8cfbf23-092f-479f-934f-6fac9e8b1d60,
964ddb73-cf83-46d8-af09-ed55dbe9e73a,
17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
62097e54-7c8d-48ca-b419-51f0584c0e3e,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5,
11450af2-985c-44a8-9472-b73dc6ee5027,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce,
435bef94-82e0-4fa8-8fea-117f9e16b6a7

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
b8608586-7364-4679-a64d-3826b8686898,
a82a08c9-d035-4122-b83c-42b933931544,
3b7b0f8a-22d5-41b9-8443-475da21a220e,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
9e3afe05-7672-45ba-8746-30b66be3fdd1,
42131e6f-5e91-454b-905d-4683d1f89cc0,
124a771f-06af-4c5d-9669-4020fbcbe2ec,
45b6e96f-1181-4133-ac15-69d0a3719c1a,
438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
window.name
The window.name API allows websites to store data that will persist after the user has navigated the tab to a different website. This mechanism could be partitioned so that data is not allowed to persist between websites.
              
Passed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_bcebd4c7-d7a9-402d-baaa-cc2ec92a1441,
name_230d0662-cf1b-4545-b3d6-f79a5fa51fce,
name_409ba143-3756-4f1b-ae02-00cf293ba63f,
name_c9708147-e276-4272-83fd-b1d199e502bd,
name_302b0701-b3ea-4cfa-9137-acf825e86529

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_c5366d00-9adf-4038-a40e-30fa84214748,
name_b9ab569e-b293-4a12-be90-a0ed912621d1,
name_4667878f-16a5-4ecd-9e94-855e7e60726f,
name_1c48fec6-4615-4891-ae9a-669a540891f0

result, different first party: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Failed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_10d65996-b480-4f3d-ba1a-82994148cebf,
name_3548065b-9016-4d4b-b100-6ed874da1441,
name_b2a2b327-6c81-459d-9d8a-27cf71cd116d,
name_15610b24-812c-4f95-a6ec-f725f40db44e,
name_a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

result, different first party: 
name_10d65996-b480-4f3d-ba1a-82994148cebf,
name_3548065b-9016-4d4b-b100-6ed874da1441,
name_b2a2b327-6c81-459d-9d8a-27cf71cd116d,
name_15610b24-812c-4f95-a6ec-f725f40db44e,
name_a0ceb013-6a3e-4f07-848d-65f91ed6a4f7

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_eebe4c45-6842-4d19-ac58-8ba38a062639,
name_4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
name_45cebc9a-6449-461a-9eaf-55fe8533da65,
name_16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
name_5ed1f834-f5f0-4741-9db0-b54a51473811

result, different first party: 
name_eebe4c45-6842-4d19-ac58-8ba38a062639,
name_4fca741f-dfdb-47b1-87a7-5a7c11f33dfd,
name_45cebc9a-6449-461a-9eaf-55fe8533da65,
name_16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd,
name_5ed1f834-f5f0-4741-9db0-b54a51473811

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_5378069e-62e6-4c65-a4d7-c26e7103a34a,
name_3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c,
name_b4870a62-d8c7-4aa3-b869-a4b56ada1280,
name_49049c26-be88-49c3-aacd-606f570a5052,
name_f5068b02-e5d5-46da-b936-704909b924d9

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_79e1ab5c-4542-4002-b9b5-b658d58b9a14,
name_c5564407-7930-46c1-a37e-f1144b78e7ec,
name_2f8f7e17-f84b-4431-b146-693b0fd9321f,
name_36348409-e50d-4651-bda3-4959f87f3001,
name_3c437474-8fee-4456-93f1-bc16a36d47d2

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_e1747d7f-3cd7-4129-82f8-10ef548b3a1d,
name_7549b7b2-c691-4ec0-853b-002bc7356afd,
name_20a4ff98-e9e0-46fc-b6fe-e284015063f6,
name_f4f8644c-fd35-4941-8573-0f784f481de5,
name_2dd62ea8-c6c3-497f-93c3-0fdd6232e392

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_1434311d-0f56-422e-84f7-59f56932dc61,
name_2d6a5964-5158-4308-a47c-d338fc246ce0,
name_820df721-3242-48ee-839b-39229099fc04,
name_187af9d9-f96d-473d-a956-a5d2ff600513,
name_dc205c47-3eeb-4d49-8103-0fc967659706

result, different first party: 
name_1434311d-0f56-422e-84f7-59f56932dc61,
name_2d6a5964-5158-4308-a47c-d338fc246ce0,
name_820df721-3242-48ee-839b-39229099fc04,
name_187af9d9-f96d-473d-a956-a5d2ff600513,
name_dc205c47-3eeb-4d49-8103-0fc967659706

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_effad01a-1965-41dc-87ed-eec28f291b5f,
name_a607723a-0d84-4334-958b-2c313172a3ba,
name_f8cfbf23-092f-479f-934f-6fac9e8b1d60,
name_964ddb73-cf83-46d8-af09-ed55dbe9e73a,
name_17c4b94d-fcd4-44b8-a08d-183aaa204c37

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_62097e54-7c8d-48ca-b419-51f0584c0e3e,
name_a8821c0e-37a5-4b1e-afc9-b63ce8542ce5,
name_11450af2-985c-44a8-9472-b73dc6ee5027,
name_3fa597cf-d3a9-48e4-9c2a-71c71e13fcce,
name_435bef94-82e0-4fa8-8fea-117f9e16b6a7

result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
name_b8608586-7364-4679-a64d-3826b8686898,
name_a82a08c9-d035-4122-b83c-42b933931544,
name_3b7b0f8a-22d5-41b9-8443-475da21a220e,
name_6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

result, different first party: 
name_d50f04af-21bb-4e36-92bb-a8b8e596a3a5,
name_b8608586-7364-4679-a64d-3826b8686898,
name_a82a08c9-d035-4122-b83c-42b933931544,
name_3b7b0f8a-22d5-41b9-8443-475da21a220e,
name_6ebce8cd-2bd6-41d5-b91c-77a52c3f5322

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_9e3afe05-7672-45ba-8746-30b66be3fdd1,
name_42131e6f-5e91-454b-905d-4683d1f89cc0,
name_124a771f-06af-4c5d-9669-4020fbcbe2ec,
name_45b6e96f-1181-4133-ac15-69d0a3719c1a,
name_438d0770-7624-4fa5-8c32-1623e842a289

result, different first party: 
name_9e3afe05-7672-45ba-8746-30b66be3fdd1,
name_42131e6f-5e91-454b-905d-4683d1f89cc0,
name_124a771f-06af-4c5d-9669-4020fbcbe2ec,
name_45b6e96f-1181-4133-ac15-69d0a3719c1a,
name_438d0770-7624-4fa5-8c32-1623e842a289

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
HTTPS testsWhich browsers prevent unencrypted network connections?
HTTPS is the protocol that web browsers use to connect securely to websites. When HTTPS is being used, the connection is encrypted so that third parties on the network cannot read content being sent between the server and your browser. In the past, insecure connections were the default and websites would need to actively request that a browser use HTTPS. Now the status quo is shifting, and browser makers are moving toward a world where HTTPS is the default protocol.`
        
Insecure website warning
Checks to see if the browser stops loading an insecure website and warns the user before giving them the option to continue. Known as HTTPS-Only Mode in some browsers.
              
Failed
passed: false,false,false,false,false
result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
Passed
passed: true,true,true,true
result: Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded
Failed
passed: false,false,false,false,false
result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
Failed
passed: false,false,false,false,false
result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
Failed
passed: false,false,false,false,false
result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
Passed
passed: true,true,true,true,true
result: Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded
Passed
passed: true,true,true,true,true
result: Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded
Failed
passed: false,false,false,false,false
result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
Failed
passed: false,false,false,false,false
result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
Passed
passed: true,true,true,true,true
result: Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded
Failed
passed: false,false,false,false,false
result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
Failed
passed: false,false,false,false,false
result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
Upgradable address
Checks to see if an insecure address entered into the browser's address bar is upgraded to HTTPS whenever possible.
              
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true
passed: true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Failed
upgraded: false,false,false,false,false
passed: false,false,false,false,false
Failed
upgraded: false,false,false,false,false
passed: false,false,false,false,false
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Upgradable hyperlink
Checks to see if the user has clicked on a hyperlink to an insecure address, if the browser upgrades that address to HTTPS whenever possible.
              
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true
passed: true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Failed
upgraded: false,false,false,false,false
passed: false,false,false,false,false
Failed
upgraded: false,false,false,false,false
passed: false,false,false,false,false
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Passed
upgraded: true,true,true,true,true
passed: true,true,true,true,true
Upgradable image
Checks to see if the browser attempts to upgrade an insecure address for an image to HTTPS whenever possible.
              
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Passed
passed: true,true,true,true
result: upgraded,upgraded,upgraded,upgraded
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Failed
passed: false,false,false,false,false
result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Failed
passed: false,false,false,false,false
result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Upgradable script
Checks to see if the browser attempts to upgrade an insecure address for an script to HTTPS whenever possible.
              
Passed
passed: true,true,true,true,true
result: blocked,blocked,blocked,blocked,blocked
Passed
passed: true,true,true,true
result: blocked,blocked,blocked,blocked
Passed
passed: true,true,true,true,true
result: blocked,blocked,blocked,blocked,blocked
Passed
passed: true,true,true,true,true
result: blocked,blocked,blocked,blocked,blocked
Passed
passed: true,true,true,true,true
result: blocked,blocked,blocked,blocked,blocked
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Passed
passed: true,true,true,true,true
result: blocked,blocked,blocked,blocked,blocked
Passed
passed: true,true,true,true,true
result: blocked,blocked,blocked,blocked,blocked
Passed
passed: true,true,true,true,true
result: upgraded,upgraded,upgraded,upgraded,upgraded
Passed
passed: true,true,true,true,true
result: blocked,blocked,blocked,blocked,blocked
Passed
passed: true,true,true,true,true
result: blocked,blocked,blocked,blocked,blocked
Misc testsWhich browsers provide additional assorted privacy protections?
This category includes tests for the presence of miscellaneous privacy features
        
ECH enabled
Encrypted Client Hello (ECH) is a new protocol that hides the website you are visiting from third-party network eavesdroppers.
              
Passed
SNI_status: encrypted
passed: true,true,true,true,true
Failed
SNI_status: plaintext
passed: false,false,false,false
Passed
SNI_status: encrypted
passed: true,true,true,true,true
Passed
SNI_status: encrypted
passed: true,true,true,true,true
Failed
SNI_status: plaintext
passed: false,false,false,false,false
Failed
SNI_status: plaintext
passed: false,false,false,false,false
Failed
SNI_status: plaintext
passed: false,false,false,false,false
Passed
SNI_status: encrypted
passed: true,true,true,true,true
Failed
SNI_status: plaintext
passed: false,false,false,false,false
Failed
SNI_status: plaintext
passed: false,false,false,false,false
Passed
SNI_status: encrypted
passed: true,true,true,true,true
Passed
SNI_status: encrypted
passed: true,true,true,true,true
GPC enabled first-party
The Global Privacy Control is an HTTP header that can be sent by a browser to instruct a website not to sell the user's personal data to third parties. This test checks to see if the GPC header is sent by default to the top-level website.
              
Passed
header value: 1
passed: true,true,true,true,true
Passed
header value: 1
passed: true,true,true,true
Failed
header value: undefined
passed: false,false,false,false,false
Failed
header value: undefined
passed: false,false,false,false,false
Passed
header value: 1
passed: true,true,true,true,true
Passed
header value: 1
passed: true,true,true,true,true
Failed
header value: undefined
passed: false,false,false,false,false
Failed
header value: undefined
passed: false,false,false,false,false
Failed
header value: undefined
passed: false,false,false,false,false
Failed
header value: undefined
passed: false,false,false,false,false
Failed
header value: undefined
passed: false,false,false,false,false
Failed
header value: undefined
passed: false,false,false,false,false
GPC enabled third-party
The Global Privacy Control is an HTTP header that can be sent by a browser to instruct a visited website not to sell the user's personal data to other parties. This test checks to see if the GPC header is sent to third-party elements on the web page.
              
Passed
sec-gpc: 1
passed: true,true,true,true,true
Passed
sec-gpc: 1
passed: true,true,true,true
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Passed
sec-gpc: 1
passed: true,true,true,true,true
Passed
sec-gpc: 1
passed: true,true,true,true,true
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
IP address leak
IP addresses can be used to uniquely identify a large percentage of users. A proxy, VPN, or Tor can mask a user's IP address.
              
Failed
passed: false,false,false,false,false
Passed
passed: true,true,true,true
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
passed: false,false,false,false,false
Failed
passed: false,false,false,false,false
Stream isolation
Browsers that use Tor can use a different Tor circuit per top-level website.
              
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true,true,true,true,true
readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
testFailed: false,false,false,false,false
Failed
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: false,false,false,false
readSameFirstParty: 185.220.101.10,2.58.56.220,192.42.116.202,109.69.67.17
readDifferentFirstParty: 185.220.101.10,2.58.56.220,192.42.116.202,109.69.67.17
passed: false,false,false,false
testFailed: false,false,false,false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true,true,true,true,true
readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
testFailed: false,false,false,false,false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true,true,true,true,true
readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
testFailed: false,false,false,false,false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true,true,true,true,true
readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
testFailed: false,false,false,false,false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true,true,true,true,true
readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
testFailed: false,false,false,false,false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true,true,true,true,true
readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
testFailed: false,false,false,false,false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true,true,true,true,true
readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
testFailed: false,false,false,false,false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true,true,true,true,true
readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
testFailed: false,false,false,false,false
Passed
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: false,false,false,false,false
readSameFirstParty: 2a0b:f4c2:1::1,2605:6400:30:f753:891d:ee77:e97c:741a,2605:6400:30:f414:42ce:c612:dab8:1337,2001:67c:6ec:203:192:42:116:186,2a0b:f4c2::23
readDifferentFirstParty: 2a0b:f4c2::12,179.43.182.232,2001:678:e3c::d,94.102.51.15,2a0b:f4c2:1::1
passed: true,true,true,true,true
testFailed: false,false,false,false,false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true,true,true,true,true
readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
testFailed: false,false,false,false,false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true,true,true,true,true
readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported
testFailed: false,false,false,false,false
Tor enabled
The Tor network sends the browser's web requests through a series of relays to hide a user's IP address, thereby helping to mask their identity and location. This test checks to see if the Tor network is being used by default.
              
Failed
IsTorExit: false,false,false,false,false
passed: false,false,false,false,false
Passed
IsTorExit: true,true,true,true
passed: true,true,true,true
Failed
IsTorExit: false,false,false,false,false
passed: false,false,false,false,false
Failed
IsTorExit: false,false,false,false,false
passed: false,false,false,false,false
Failed
IsTorExit: false,false,false,false,false
passed: false,false,false,false,false
Failed
IsTorExit: false,false,false,false,false
passed: false,false,false,false,false
Failed
IsTorExit: false,false,false,false,false
passed: false,false,false,false,false
Failed
IsTorExit: false,false,false,false,false
passed: false,false,false,false,false
Failed
IsTorExit: false,false,false,false,false
passed: false,false,false,false,false
Passed
IsTorExit: true,true,true,true,true
passed: true,true,true,true,true
Failed
IsTorExit: false,false,false,false,false
passed: false,false,false,false,false
Failed
IsTorExit: false,false,false,false,false
passed: false,false,false,false,false
Fingerprinting resistance testsWhich browsers hide what's unique about your device?
Fingerprinting is a technique trackers use to uniquely identify you as you browse the web. A fingerprinting script will measure several characteristics of your browser and, combining this data, will build a fingerprint that may uniquely identify you among web users. Browsers can introduce countermeasures, such as minimizing the distinguishing information disclosed by certain web APIs so your browser is harder to pick out from the crowd (so-called 'fingerprinting resistance').`,
        
Media query screen height
Height of the user's screen in pixels.
              
Passed
expression: undefined
desired expression: undefined
actual value: 1302,1298,1296,1296,1301
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 1298,1299,1301,1304
desired value: undefined
passed: true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Media query screen width
Width of the user's screen in pixels.
              
Passed
expression: undefined
desired expression: undefined
actual value: 1208,1203,1204,1206,1208
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 1207,1201,1203,1205
desired value: undefined
passed: true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: 1600,1600,1600,1600,1600
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 1400,1400,1400,1400,1400
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: 1400,1400,1400,1400,1400
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
outerHeight
Height of the browser window in pixels, including browser chrome.
              
Passed
expression: outerHeight
desired expression: undefined
actual value: 1302,1298,1296,1296,1301
desired value: undefined
passed: true,true,true,true,true
Passed
expression: outerHeight
desired expression: undefined
actual value: 1298,1299,1301,1304
desired value: undefined
passed: true,true,true,true
Failed
expression: outerHeight
desired expression: undefined
actual value: 1371,1371,1371,1371,1371
desired value: undefined
passed: false,false,false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 1371,1371,1371,1371,1371
desired value: undefined
passed: false,false,false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 1040,1040,1040,1040,1040
desired value: undefined
passed: false,false,false,false,false
Passed
expression: outerHeight
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Passed
expression: outerHeight
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Failed
expression: outerHeight
desired expression: undefined
actual value: 1061,1061,1061,1061,1061
desired value: undefined
passed: false,false,false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 1335,1335,1335,1335,1335
desired value: undefined
passed: false,false,false,false,false
Passed
expression: outerHeight
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Failed
expression: outerHeight
desired expression: undefined
actual value: 1371,1371,1371,1371,1371
desired value: undefined
passed: false,false,false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 1371,1371,1371,1371,1371
desired value: undefined
passed: false,false,false,false,false
screen.height
Height of the user's screen, in pixels.
              
Passed
expression: screen.height
desired expression: undefined
actual value: 1302,1298,1296,1296,1301
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screen.height
desired expression: undefined
actual value: 1298,1299,1301,1304
desired value: undefined
passed: true,true,true,true
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Passed
expression: screen.height
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screen.height
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Passed
expression: screen.height
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
screen.width
Width of the user's screen, in pixels.
              
Passed
expression: screen.width
desired expression: undefined
actual value: 1208,1203,1204,1206,1208
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screen.width
desired expression: undefined
actual value: 1207,1201,1203,1205
desired value: undefined
passed: true,true,true,true
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Passed
expression: screen.width
desired expression: undefined
actual value: 1600,1600,1600,1600,1600
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screen.width
desired expression: undefined
actual value: 1400,1400,1400,1400,1400
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Passed
expression: screen.width
desired expression: undefined
actual value: 1400,1400,1400,1400,1400
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
screenX
Position, in pixels, of the left edge of the browser window on screen.
              
Passed
expression: screenX
desired expression: undefined
actual value: 5,2,2,1,6
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 3,6,7,0
desired value: undefined
passed: true,true,true,true
Failed
expression: screenX
desired expression: undefined
actual value: 22,22,22,22,22
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenX
desired expression: undefined
actual value: 22,22,22,22,22
desired value: undefined
passed: false,false,false,false,false
Passed
expression: screenX
desired expression: undefined
actual value: 4,4,4,4,4
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0,0,0
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0,0,0
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screenX
desired expression: undefined
actual value: 320,320,320,320,320
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenX
desired expression: undefined
actual value: 243,243,243,243,243
desired value: undefined
passed: false,false,false,false,false
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0,0,0
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screenX
desired expression: undefined
actual value: 22,22,22,22,22
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenX
desired expression: undefined
actual value: 22,22,22,22,22
desired value: undefined
passed: false,false,false,false,false
screenY
Position, in pixels, of the top edge of the browser window on screen.
              
Passed
expression: screenY
desired expression: undefined
actual value: 8,5,5,1,0
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 8,8,8,0
desired value: undefined
passed: true,true,true,true
Failed
expression: screenY
desired expression: undefined
actual value: 47,47,47,47,47
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenY
desired expression: undefined
actual value: 47,47,47,47,47
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenY
desired expression: undefined
actual value: 25,25,25,25,25
desired value: undefined
passed: false,false,false,false,false
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0,0,0
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0,0,0
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screenY
desired expression: undefined
actual value: 202,202,202,202,202
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenY
desired expression: undefined
actual value: 57,57,57,57,57
desired value: undefined
passed: false,false,false,false,false
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0,0,0
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screenY
desired expression: undefined
actual value: 47,47,47,47,47
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenY
desired expression: undefined
actual value: 47,47,47,47,47
desired value: undefined
passed: false,false,false,false,false
System font detection
Web pages can detect the presence of a font installed on the user's system. The presence or absence of various fonts is commonly used to fingerprint users.
              
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false,false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false,false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false,false,false,false
Tracking query parameter testsWhich browsers remove URL parameters that can track you?
When you browse from one web page to another, tracking companies will frequently attach a 'tracking query parameter' to the address of the second web page. That query parameter may contain a unique identifier that tracks you individually as you browse the web. And these query parameters are frequently synchronized with cookies, making them a powerful tracking vector. Web browsers can protect you from known tracking query parameters by stripping them from web addresses before your browser sends them. (The set of tracking query parameters tested here was largely borrowed from Brave.)`
        
__hsfp
HubSpot tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
__hssc
HubSpot tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
__hstc
HubSpot tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
__s
Drip.com email address tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
_hsenc
HubSpot tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
_openstat
Yandex tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
dclid
DoubleClick Click ID (Google)
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
fbclid
Facebook Click Identifier
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
gclid
Google Click Identifier
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
hsCtaTracking
HubSpot tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
mc_eid
Mailchimp Email ID (email recipient's address)
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
mkt_tok
Adobe Marketo tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
ml_subscriber
MailerLite email tracking
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
ml_subscriber_hash
MailerLite email tracking
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
msclkid
Microsoft Click ID
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
oly_anon_id
Omeda marketing 'anonymous' customer id
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
oly_enc_id
Omeda marketing 'known' customer id
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
rb_clickid
Unknown high-entropy tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
s_cid
Adobe Site Catalyst tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
vero_conv
Vero tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
vero_id
Vero tracking parameter
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
wickedid
Wicked Reports e-commerce tracking
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
yclid
Yandex Click ID
              
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Passed
passed: true,true,true,true,true
Failed
value: 18359530689066839
passed: false,false,false,false,false
Failed
value: 18359530689066839
passed: false,false,false,false,false
Tracker content blocking testsWhich browsers block important known tracking scripts and pixels?
When you visit a web page, it frequently has third-party embedded tracking content, such as scripts and tracking pixels. These embedded components spy on you. Some browsers and browser extensions maintain list of tracking companies and block their content from being loaded. This section checks to see if a browser blocks 20 of the largest trackers listed by https://whotracks.me.`
        
Adobe
Tests whether the browser blocks the page from loading the tracker at https://munchkin.marketo.net/munchkin.js
              
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true,true,true,true,true
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true,true,true,true
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false,false,false,false,false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false,false,false,false,false
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true,true,true,true,true
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true,true,true,true,true
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true,true,true,true,true
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false,false,false,false,false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false,false,false,false,false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false,false,false,false,false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false,false,false,false,false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false,false,false,false,false
Adobe Audience Manager
Tests whether the browser blocks the page from loading the tracker at https://dpm.demdex.net/ibs
              
Passed
url: https://dpm.demdex.net/ibs
passed: true,true,true,true,true
Passed
url: https://dpm.demdex.net/ibs
passed: true,true,true,true
Failed
url: https://dpm.demdex.net/ibs
passed: false,false,false,false,false
Failed
url: https://dpm.demdex.net/ibs
passed: false,false,false,false,false
Passed
url: https://dpm.demdex.net/ibs
passed: true,true,true,true,true
Passed
url: https://dpm.demdex.net/ibs
passed: true,true,true,true,true
Passed
url: https://dpm.demdex.net/ibs
passed: true,true,true,true,true
Failed
url: https://dpm.demdex.net/ibs
passed: false,false,false,false,false
Failed
url: https://dpm.demdex.net/ibs
passed: false,false,false,false,false
Failed
url: https://dpm.demdex.net/ibs
passed: false,false,false,false,false
Failed
url: https://dpm.demdex.net/ibs
passed: false,false,false,false,false
Failed
url: https://dpm.demdex.net/ibs
passed: false,false,false,false,false
Amazon adsystem
Tests whether the browser blocks the page from loading the tracker at https://s.amazon-adsystem.com/dcm
              
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true,true,true,true,true
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true,true,true,true
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false,false,false,false,false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false,false,false,false,false
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true,true,true,true,true
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true,true,true,true,true
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true,true,true,true,true
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false,false,false,false,false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false,false,false,false,false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false,false,false,false,false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false,false,false,false,false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false,false,false,false,false
AppNexus
Tests whether the browser blocks the page from loading the tracker at https://ib.adnxs.com/px?id=178248&t=1
              
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true,true,true,true,true
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true,true,true,true
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false,false,false,false,false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false,false,false,false,false
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true,true,true,true,true
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true,true,true,true,true
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true,true,true,true,true
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false,false,false,false,false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false,false,false,false,false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false,false,false,false,false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false,false,false,false,false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false,false,false,false,false
Bing Ads
Tests whether the browser blocks the page from loading the tracker at https://bat.bing.com/bat.js
              
Passed
url: https://bat.bing.com/bat.js
passed: true,true,true,true,true
Passed
url: https://bat.bing.com/bat.js
passed: true,true,true,true
Failed
url: https://bat.bing.com/bat.js
passed: false,false,false,false,false
Failed
url: https://bat.bing.com/bat.js
passed: false,false,false,false,false
Passed
url: https://bat.bing.com/bat.js
passed: true,true,true,true,true
Passed
url: https://bat.bing.com/bat.js
passed: true,true,true,true,true
Passed
url: https://bat.bing.com/bat.js
passed: true,true,true,true,true
Failed
url: https://bat.bing.com/bat.js
passed: false,false,false,false,false
Failed
url: https://bat.bing.com/bat.js
passed: false,false,false,false,false
Failed
url: https://bat.bing.com/bat.js
passed: false,false,false,false,false
Failed
url: https://bat.bing.com/bat.js
passed: false,false,false,false,false
Failed
url: https://bat.bing.com/bat.js
passed: false,false,false,false,false
Chartbeat
Tests whether the browser blocks the page from loading the tracker at https://static.chartbeat.com/js/chartbeat.js
              
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true,true,true,true,true
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true,true,true,true
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false,false,false,false,false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false,false,false,false,false
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true,true,true,true,true
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true,true,true,true,true
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true,true,true,true,true
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false,false,false,false,false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false,false,false,false,false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false,false,false,false,false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false,false,false,false,false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false,false,false,false,false
Criteo
Tests whether the browser blocks the page from loading the tracker at https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
              
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true,true,true,true,true
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true,true,true,true
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false,false,false,false,false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false,false,false,false,false
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true,true,true,true,true
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true,true,true,true,true
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true,true,true,true,true
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false,false,false,false,false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false,false,false,false,false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false,false,false,false,false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false,false,false,false,false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false,false,false,false,false
DoubleClick (Google)
Tests whether the browser blocks the page from loading the tracker at https://securepubads.g.doubleclick.net/static/glade.js
              
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true,true,true,true,true
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true,true,true,true
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false,false,false,false,false
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false,false,false,false,false
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true,true,true,true,true
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true,true,true,true,true
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true,true,true,true,true
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false,false,false,false,false
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false,false,false,false,false
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false,false,false,false,false
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false,false,false,false,false
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false,false,false,false,false
Facebook tracking
Tests whether the browser blocks the page from loading the tracker at https://connect.facebook.net/en_US/fbevents.js
              
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true,true,true,true,true
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true,true,true,true
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false,false,false,false,false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false,false,false,false,false
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true,true,true,true,true
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true,true,true,true,true
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true,true,true,true,true
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false,false,false,false,false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false,false,false,false,false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false,false,false,false,false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false,false,false,false,false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false,false,false,false,false
Google (third-party ad pixel)
Tests whether the browser blocks the page from loading the tracker at https://www.google.com/pagead/1p-user-list/
              
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true,true,true,true,true
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true,true,true,true
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false,false,false,false,false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false,false,false,false,false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false,false,false,false,false
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true,true,true,true,true
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true,true,true,true,true
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false,false,false,false,false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false,false,false,false,false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false,false,false,false,false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false,false,false,false,false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false,false,false,false,false
Google Analytics
Tests whether the browser blocks the page from loading the tracker at https://google-analytics.com/urchin.js
              
Passed
url: https://google-analytics.com/urchin.js
passed: true,true,true,true,true
Passed
url: https://google-analytics.com/urchin.js
passed: true,true,true,true
Failed
url: https://google-analytics.com/urchin.js
passed: false,false,false,false,false
Failed
url: https://google-analytics.com/urchin.js
passed: false,false,false,false,false
Passed
url: https://google-analytics.com/urchin.js
passed: true,true,true,true,true
Passed
url: https://google-analytics.com/urchin.js
passed: true,true,true,true,true
Passed
url: https://google-analytics.com/urchin.js
passed: true,true,true,true,true
Failed
url: https://google-analytics.com/urchin.js
passed: false,false,false,false,false
Failed
url: https://google-analytics.com/urchin.js
passed: false,false,false,false,false
Failed
url: https://google-analytics.com/urchin.js
passed: false,false,false,false,false
Failed
url: https://google-analytics.com/urchin.js
passed: false,false,false,false,false
Failed
url: https://google-analytics.com/urchin.js
passed: false,false,false,false,false
Google Tag Manager
Tests whether the browser blocks the page from loading the tracker at https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
              
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true,true,true,true,true
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true,true,true,true
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false,false,false,false,false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false,false,false,false,false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false,false,false,false,false
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true,true,true,true,true
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true,true,true,true,true
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false,false,false,false,false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false,false,false,false,false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false,false,false,false,false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false,false,false,false,false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false,false,false,false,false
Index Exchange
Tests whether the browser blocks the page from loading the tracker at https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
              
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true,true,true,true,true
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true,true,true,true
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false,false,false,false,false
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false,false,false,false,false
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true,true,true,true,true
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true,true,true,true,true
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true,true,true,true,true
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false,false,false,false,false
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false,false,false,false,false
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false,false,false,false,false
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false,false,false,false,false
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false,false,false,false,false
New Relic
Tests whether the browser blocks the page from loading the tracker at https://js-agent.newrelic.com/nr-1212.min.js
              
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true,true,true,true,true
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true,true,true,true
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false,false,false,false,false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false,false,false,false,false
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true,true,true,true,true
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true,true,true,true,true
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true,true,true,true,true
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false,false,false,false,false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false,false,false,false,false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false,false,false,false,false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false,false,false,false,false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false,false,false,false,false
Quantcast
Tests whether the browser blocks the page from loading the tracker at https://pixel.quantserve.com/pixel
              
Passed
url: https://pixel.quantserve.com/pixel
passed: true,true,true,true,true
Passed
url: https://pixel.quantserve.com/pixel
passed: true,true,true,true
Failed
url: https://pixel.quantserve.com/pixel
passed: false,false,false,false,false
Failed
url: https://pixel.quantserve.com/pixel
passed: false,false,false,false,false
Passed
url: https://pixel.quantserve.com/pixel
passed: true,true,true,true,true
Passed
url: https://pixel.quantserve.com/pixel
passed: true,true,true,true,true
Passed
url: https://pixel.quantserve.com/pixel
passed: true,true,true,true,true
Failed
url: https://pixel.quantserve.com/pixel
passed: false,false,false,false,false
Failed
url: https://pixel.quantserve.com/pixel
passed: false,false,false,false,false
Failed
url: https://pixel.quantserve.com/pixel
passed: false,false,false,false,false
Failed
url: https://pixel.quantserve.com/pixel
passed: false,false,false,false,false
Failed
url: https://pixel.quantserve.com/pixel
passed: false,false,false,false,false
Scorecard Research Beacon
Tests whether the browser blocks the page from loading the tracker at https://sb.scorecardresearch.com/internal-c2/default/cs.js
              
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true,true,true,true,true
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true,true,true,true
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false,false,false,false,false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false,false,false,false,false
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true,true,true,true,true
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true,true,true,true,true
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true,true,true,true,true
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false,false,false,false,false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false,false,false,false,false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false,false,false,false,false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false,false,false,false,false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false,false,false,false,false
Taboola
Tests whether the browser blocks the page from loading the tracker at https://trc.taboola.com/futureplc-tomsguide/trc/3/json
              
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true,true,true,true,true
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true,true,true,true
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false,false,false,false,false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false,false,false,false,false
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true,true,true,true,true
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true,true,true,true,true
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true,true,true,true,true
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false,false,false,false,false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false,false,false,false,false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false,false,false,false,false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false,false,false,false,false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false,false,false,false,false
Twitter pixel
Tests whether the browser blocks the page from loading the tracker at https://t.co/i/adsct
              
Passed
url: https://t.co/i/adsct
passed: true,true,true,true,true
Passed
url: https://t.co/i/adsct
passed: true,true,true,true
Failed
url: https://t.co/i/adsct
passed: false,false,false,false,false
Failed
url: https://t.co/i/adsct
passed: false,false,false,false,false
Passed
url: https://t.co/i/adsct
passed: true,true,true,true,true
Passed
url: https://t.co/i/adsct
passed: true,true,true,true,true
Passed
url: https://t.co/i/adsct
passed: true,true,true,true,true
Failed
url: https://t.co/i/adsct
passed: false,false,false,false,false
Failed
url: https://t.co/i/adsct
passed: false,false,false,false,false
Failed
url: https://t.co/i/adsct
passed: false,false,false,false,false
Failed
url: https://t.co/i/adsct
passed: false,false,false,false,false
Failed
url: https://t.co/i/adsct
passed: false,false,false,false,false
Yandex Ads
Tests whether the browser blocks the page from loading the tracker at https://yandex.ru/ads/system/header-bidding.js
              
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true,true,true,true,true
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true,true,true,true
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false,false,false,false,false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false,false,false,false,false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false,false,false,false,false
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true,true,true,true,true
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true,true,true,true,true
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false,false,false,false,false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false,false,false,false,false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false,false,false,false,false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false,false,false,false,false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false,false,false,false,false
Tracking cookie protection testsWhich browsers block important known tracking cookies?
A large fraction of web pages on the web have hidden third-party trackers that read and write cookies in your browser. These cookies can be used to track your browsing across websites. This section checks to see if a browser stops cross-site tracking by cookies from 20 of the largest trackers listed by https://whotracks.me.`,
        
Adobe
Tests whether the browser stops cookies from munchkin.marketo.net from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false,false,false,false,false
Adobe Audience Manager
Tests whether the browser stops cookies from dpm.demdex.net from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dpm.demdex.net/ibs
cookieFound: false,false,false,false,false
Amazon adsystem
Tests whether the browser stops cookies from s.amazon-adsystem.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false,false,false,false,false
AppNexus
Tests whether the browser stops cookies from ib.adnxs.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false,false,false,false,false
Bing Ads
Tests whether the browser stops cookies from bat.bing.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://bat.bing.com/bat.js
cookieFound: false,false,false,false,false
Chartbeat
Tests whether the browser stops cookies from static.chartbeat.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false,false
Failed
passed: false,false,false,false,false
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: true,true,true,true,true
Passed
passed: true,true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false,false,false,false,false
Criteo
Tests whether the browser stops cookies from dis.criteo.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false,false,false,false,false
DoubleClick (Google)
Tests whether the browser stops cookies from securepubads.g.doubleclick.net from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false,false,false,false,false
Facebook tracking
Tests whether the browser stops cookies from connect.facebook.net from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false,false,false,false,false
Google (third-party ad pixel)
Tests whether the browser stops cookies from www.google.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false,false,false,false,false
Google Analytics
Tests whether the browser stops cookies from google-analytics.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false,false
Failed
passed: false,false,false,false,false
url: https://google-analytics.com/urchin.js
cookieFound: true,true,true,true,true
Passed
passed: true,true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://google-analytics.com/urchin.js
cookieFound: false,false,false,false,false
Google Tag Manager
Tests whether the browser stops cookies from www.googletagmanager.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false,false
Failed
passed: false,false,false,false,false
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: true,true,true,true,true
Passed
passed: true,true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false,false,false,false,false
Index Exchange
Tests whether the browser stops cookies from dsum-sec.casalemedia.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false,false,false,false,false
New Relic
Tests whether the browser stops cookies from js-agent.newrelic.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false,false
Failed
passed: false,false,false,false,false
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: true,true,true,true,true
Passed
passed: true,true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false,false,false,false,false
Quantcast
Tests whether the browser stops cookies from pixel.quantserve.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://pixel.quantserve.com/pixel
cookieFound: false,false,false,false,false
Scorecard Research Beacon
Tests whether the browser stops cookies from sb.scorecardresearch.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false,false
Failed
passed: false,false,false,false,false
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: true,true,true,true,true
Passed
passed: true,true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false,false,false,false,false
Taboola
Tests whether the browser stops cookies from trc.taboola.com from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false,false,false,false,false
Twitter pixel
Tests whether the browser stops cookies from t.co from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false,false
Failed
passed: false,false,false,false,false
url: https://t.co/i/adsct
cookieFound: true,true,true,true,true
Passed
passed: true,true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://t.co/i/adsct
cookieFound: false,false,false,false,false
Yandex Ads
Tests whether the browser stops cookies from yandex.ru from tracking users across websites.
              
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Passed
passed: true,true,true,true,true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false,false,false,false,false
Cross-session first-party tracking testsWhich browsers prevent websites from tracking you across browser sessions?
A common vulnerability of web browsers is that they allow websites ("first parties") to 'tag' your browser with some tracking data. This tag can be used to re-identify you when you return to a website you visited before. This category of leaks can be prevented by browser if they clean or isolate data between browser sessions. (In cases where a user has logged into a website or entered detailed information, it may be justifiable for a browser to retain information across sessions. These tests check when no such justification exists: when you have entered no significant information into a website, will the browser still retain data that allows you to be tracked across sessions?)
        
Alt-Svc
Alt-Svc allows the server to indicate to the web browser that a resource should be loaded on a different server. Because this is a persistent setting, it could be used to track users across websites if it is not correctly partitioned.
              
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h2, h2, h2, h2

result, different session: h2, h2, h2, h2

unsupported: true, true, true, true

passed: undefined

test failed: false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h2, h3, h2, h3

result, different session: h2, h3, h2, h3, h2

unsupported: false, true, false, true, false

passed: true, true, true

test failed: false, false, false, false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h2, h2, h2, h2, h2

result, different session: h2, h2, h2, h2, h2

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
CacheStorage
The Cache API is a content storage mechanism originally introduced to support ServiceWorkers. If the same Cache object is accessible to multiple websites, it can be abused to track users.
              
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_1p,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_1p,
409ba143-3756-4f1b-ae02-00cf293ba63f_1p,
c9708147-e276-4272-83fd-b1d199e502bd_1p,
302b0701-b3ea-4cfa-9137-acf825e86529_1p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
c5366d00-9adf-4038-a40e-30fa84214748_1p,
b9ab569e-b293-4a12-be90-a0ed912621d1_1p,
4667878f-16a5-4ecd-9e94-855e7e60726f_1p,
1c48fec6-4615-4891-ae9a-669a540891f0_1p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
10d65996-b480-4f3d-ba1a-82994148cebf_1p,
3548065b-9016-4d4b-b100-6ed874da1441_1p,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_1p,
15610b24-812c-4f95-a6ec-f725f40db44e_1p,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_1p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_1p,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_1p,
45cebc9a-6449-461a-9eaf-55fe8533da65_1p,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_1p,
5ed1f834-f5f0-4741-9db0-b54a51473811_1p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
1434311d-0f56-422e-84f7-59f56932dc61_1p,
2d6a5964-5158-4308-a47c-d338fc246ce0_1p,
820df721-3242-48ee-839b-39229099fc04_1p,
187af9d9-f96d-473d-a956-a5d2ff600513_1p,
dc205c47-3eeb-4d49-8103-0fc967659706_1p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
effad01a-1965-41dc-87ed-eec28f291b5f_1p,
a607723a-0d84-4334-958b-2c313172a3ba_1p,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_1p,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_1p,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_1p

result, different session: 
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_1p,
b8608586-7364-4679-a64d-3826b8686898_1p,
a82a08c9-d035-4122-b83c-42b933931544_1p,
3b7b0f8a-22d5-41b9-8443-475da21a220e_1p,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_1p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_1p,
42131e6f-5e91-454b-905d-4683d1f89cc0_1p,
124a771f-06af-4c5d-9669-4020fbcbe2ec_1p,
45b6e96f-1181-4133-ac15-69d0a3719c1a_1p,
438d0770-7624-4fa5-8c32-1623e842a289_1p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
cookie (HTTP)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
              
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_1p_http,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_1p_http,
409ba143-3756-4f1b-ae02-00cf293ba63f_1p_http,
c9708147-e276-4272-83fd-b1d199e502bd_1p_http,
302b0701-b3ea-4cfa-9137-acf825e86529_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
c5366d00-9adf-4038-a40e-30fa84214748_1p_http,
b9ab569e-b293-4a12-be90-a0ed912621d1_1p_http,
4667878f-16a5-4ecd-9e94-855e7e60726f_1p_http,
1c48fec6-4615-4891-ae9a-669a540891f0_1p_http

result, different session: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
10d65996-b480-4f3d-ba1a-82994148cebf_1p_http,
3548065b-9016-4d4b-b100-6ed874da1441_1p_http,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_1p_http,
15610b24-812c-4f95-a6ec-f725f40db44e_1p_http,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_1p_http,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_1p_http,
45cebc9a-6449-461a-9eaf-55fe8533da65_1p_http,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_1p_http,
5ed1f834-f5f0-4741-9db0-b54a51473811_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
5378069e-62e6-4c65-a4d7-c26e7103a34a_1p_http,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c_1p_http,
b4870a62-d8c7-4aa3-b869-a4b56ada1280_1p_http,
49049c26-be88-49c3-aacd-606f570a5052_1p_http,
f5068b02-e5d5-46da-b936-704909b924d9_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14_1p_http,
c5564407-7930-46c1-a37e-f1144b78e7ec_1p_http,
2f8f7e17-f84b-4431-b146-693b0fd9321f_1p_http,
36348409-e50d-4651-bda3-4959f87f3001_1p_http,
3c437474-8fee-4456-93f1-bc16a36d47d2_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d_1p_http,
7549b7b2-c691-4ec0-853b-002bc7356afd_1p_http,
20a4ff98-e9e0-46fc-b6fe-e284015063f6_1p_http,
f4f8644c-fd35-4941-8573-0f784f481de5_1p_http,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
1434311d-0f56-422e-84f7-59f56932dc61_1p_http,
2d6a5964-5158-4308-a47c-d338fc246ce0_1p_http,
820df721-3242-48ee-839b-39229099fc04_1p_http,
187af9d9-f96d-473d-a956-a5d2ff600513_1p_http,
dc205c47-3eeb-4d49-8103-0fc967659706_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
effad01a-1965-41dc-87ed-eec28f291b5f_1p_http,
a607723a-0d84-4334-958b-2c313172a3ba_1p_http,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_1p_http,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_1p_http,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_1p_http

result, different session: 
effad01a-1965-41dc-87ed-eec28f291b5f_1p_http,
a607723a-0d84-4334-958b-2c313172a3ba_1p_http,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_1p_http,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_1p_http,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_1p_http

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
62097e54-7c8d-48ca-b419-51f0584c0e3e_1p_http,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5_1p_http,
11450af2-985c-44a8-9472-b73dc6ee5027_1p_http,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce_1p_http,
435bef94-82e0-4fa8-8fea-117f9e16b6a7_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_1p_http,
b8608586-7364-4679-a64d-3826b8686898_1p_http,
a82a08c9-d035-4122-b83c-42b933931544_1p_http,
3b7b0f8a-22d5-41b9-8443-475da21a220e_1p_http,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_1p_http,
42131e6f-5e91-454b-905d-4683d1f89cc0_1p_http,
124a771f-06af-4c5d-9669-4020fbcbe2ec_1p_http,
45b6e96f-1181-4133-ac15-69d0a3719c1a_1p_http,
438d0770-7624-4fa5-8c32-1623e842a289_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
cookie (JS)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
              
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_1p_js,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_1p_js,
409ba143-3756-4f1b-ae02-00cf293ba63f_1p_js,
c9708147-e276-4272-83fd-b1d199e502bd_1p_js,
302b0701-b3ea-4cfa-9137-acf825e86529_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
c5366d00-9adf-4038-a40e-30fa84214748_1p_js,
b9ab569e-b293-4a12-be90-a0ed912621d1_1p_js,
4667878f-16a5-4ecd-9e94-855e7e60726f_1p_js,
1c48fec6-4615-4891-ae9a-669a540891f0_1p_js

result, different session: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
10d65996-b480-4f3d-ba1a-82994148cebf_1p_js,
3548065b-9016-4d4b-b100-6ed874da1441_1p_js,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_1p_js,
15610b24-812c-4f95-a6ec-f725f40db44e_1p_js,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_1p_js,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_1p_js,
45cebc9a-6449-461a-9eaf-55fe8533da65_1p_js,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_1p_js,
5ed1f834-f5f0-4741-9db0-b54a51473811_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
5378069e-62e6-4c65-a4d7-c26e7103a34a_1p_js,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c_1p_js,
b4870a62-d8c7-4aa3-b869-a4b56ada1280_1p_js,
49049c26-be88-49c3-aacd-606f570a5052_1p_js,
f5068b02-e5d5-46da-b936-704909b924d9_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14_1p_js,
c5564407-7930-46c1-a37e-f1144b78e7ec_1p_js,
2f8f7e17-f84b-4431-b146-693b0fd9321f_1p_js,
36348409-e50d-4651-bda3-4959f87f3001_1p_js,
3c437474-8fee-4456-93f1-bc16a36d47d2_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d_1p_js,
7549b7b2-c691-4ec0-853b-002bc7356afd_1p_js,
20a4ff98-e9e0-46fc-b6fe-e284015063f6_1p_js,
f4f8644c-fd35-4941-8573-0f784f481de5_1p_js,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
1434311d-0f56-422e-84f7-59f56932dc61_1p_js,
2d6a5964-5158-4308-a47c-d338fc246ce0_1p_js,
820df721-3242-48ee-839b-39229099fc04_1p_js,
187af9d9-f96d-473d-a956-a5d2ff600513_1p_js,
dc205c47-3eeb-4d49-8103-0fc967659706_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
effad01a-1965-41dc-87ed-eec28f291b5f_1p_js,
a607723a-0d84-4334-958b-2c313172a3ba_1p_js,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_1p_js,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_1p_js,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
62097e54-7c8d-48ca-b419-51f0584c0e3e_1p_js,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5_1p_js,
11450af2-985c-44a8-9472-b73dc6ee5027_1p_js,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce_1p_js,
435bef94-82e0-4fa8-8fea-117f9e16b6a7_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_1p_js,
b8608586-7364-4679-a64d-3826b8686898_1p_js,
a82a08c9-d035-4122-b83c-42b933931544_1p_js,
3b7b0f8a-22d5-41b9-8443-475da21a220e_1p_js,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_1p_js,
42131e6f-5e91-454b-905d-4683d1f89cc0_1p_js,
124a771f-06af-4c5d-9669-4020fbcbe2ec_1p_js,
45b6e96f-1181-4133-ac15-69d0a3719c1a_1p_js,
438d0770-7624-4fa5-8c32-1623e842a289_1p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
CookieStore
The Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.
              
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_1p,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_1p,
409ba143-3756-4f1b-ae02-00cf293ba63f_1p,
c9708147-e276-4272-83fd-b1d199e502bd_1p,
302b0701-b3ea-4cfa-9137-acf825e86529_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
c5366d00-9adf-4038-a40e-30fa84214748_1p,
b9ab569e-b293-4a12-be90-a0ed912621d1_1p,
4667878f-16a5-4ecd-9e94-855e7e60726f_1p,
1c48fec6-4615-4891-ae9a-669a540891f0_1p

result, different session: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
10d65996-b480-4f3d-ba1a-82994148cebf_1p,
3548065b-9016-4d4b-b100-6ed874da1441_1p,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_1p,
15610b24-812c-4f95-a6ec-f725f40db44e_1p,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_1p,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_1p,
45cebc9a-6449-461a-9eaf-55fe8533da65_1p,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_1p,
5ed1f834-f5f0-4741-9db0-b54a51473811_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
1434311d-0f56-422e-84f7-59f56932dc61_1p,
2d6a5964-5158-4308-a47c-d338fc246ce0_1p,
820df721-3242-48ee-839b-39229099fc04_1p,
187af9d9-f96d-473d-a956-a5d2ff600513_1p,
dc205c47-3eeb-4d49-8103-0fc967659706_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_1p,
b8608586-7364-4679-a64d-3826b8686898_1p,
a82a08c9-d035-4122-b83c-42b933931544_1p,
3b7b0f8a-22d5-41b9-8443-475da21a220e_1p,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_1p,
42131e6f-5e91-454b-905d-4683d1f89cc0_1p,
124a771f-06af-4c5d-9669-4020fbcbe2ec_1p,
45b6e96f-1181-4133-ac15-69d0a3719c1a_1p,
438d0770-7624-4fa5-8c32-1623e842a289_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
CSS cache
CSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.
              
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_38051124834907113,
fake_03312934550240931,
fake_41193346931859276,
fake_24968281475347065,
fake_29554502455223775

result, different session: 
fake_20777649262202158,
fake_6984639514866924,
fake_11866179661239551,
fake_9523934117074719,
fake_8771463502843138

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_3376022264159402,
fake_26436370197833736,
fake_25844746324866574,
fake_6967381351112172

result, different session: 
fake_06579907300514964,
fake_2066745718291858,
fake_8970297364934703,
fake_6967784465040989

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_35262767618029534,
fake_9261807094978918,
fake_4860974712826329,
fake_2093041135488518,
fake_14668843221549577

result, different session: 
fake_5281085548962743,
fake_5929352167582156,
fake_9613457699694619,
fake_01907871834240127,
fake_9887027466479179

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_5335868686512588,
fake_23884282646344523,
fake_10639938517947556,
fake_9074400117122663,
fake_2855294371162589

result, different session: 
fake_050742594045914746,
fake_9728762317761879,
fake_4388439072524233,
fake_12150612150249529,
fake_9723404818403019

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_6291341002535584,
fake_7050215126336647,
fake_5472489117850416,
fake_6587734679910262,
fake_6644881051078819

result, different session: 
fake_8259155174053483,
fake_8880250995101999,
fake_42028239241887055,
fake_13994403863241134,
fake_8379147829843494

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_7647069725617506,
fake_9652600105751532,
fake_861706368224127,
fake_5899730394533649,
fake_0898448991546601

result, different session: 
fake_07135171532009821,
fake_882739861604894,
fake_5334722103204566,
fake_7104857473682313,
fake_49859112372391334

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_5019882216332792,
fake_9248976546720189,
fake_7289788349674355,
fake_1277168947648133,
fake_7261477549058191

result, different session: 
fake_5125348248529076,
fake_17362134860813216,
fake_6533102773725536,
fake_4188485298093445,
fake_06499238599217194

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_49626333959178015,
fake_16140577788248844,
fake_942488132158882,
fake_13724128842464545,
fake_2796087149250961

result, different session: 
fake_008031200370367975,
fake_005010657942074115,
fake_16211574883326763,
fake_6086816787330764,
fake_20149761045463377

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_8392216594442179,
fake_09736237239569712,
fake_09039979447036073,
fake_9162991382441468,
fake_912835627399601

result, different session: 
fake_8392216594442179,
fake_09736237239569712,
fake_09039979447036073,
fake_9162991382441468,
fake_912835627399601

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_14719240723462912,
fake_993528804455275,
fake_20189082782185364,
fake_7247929445948582,
fake_45728092681485943

result, different session: 
fake_7347162043860596,
fake_7200375121218314,
fake_6487648426296297,
fake_3582613322414707,
fake_7739702137343829

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_757506798390879,
fake_07410940657130949,
fake_6873687376209834,
fake_7193699252784904,
fake_34091107258051867

result, different session: 
fake_01804152872800846,
fake_8738614565201426,
fake_8384095496324058,
fake_9674310099080721,
fake_48065855690700565

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_18518445681742124,
fake_25543900826348986,
fake_8908091310225228,
fake_36364097364888304,
fake_18745448582954793

result, different session: 
fake_22799338870300168,
fake_7390414041529185,
fake_37117493063266993,
fake_30145690858931906,
fake_3360292676490513

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
favicon cache
A favicon is an icon that represents a website, typically shown in browser tab and bookmarks menu. If the favicon cache is not partitioned, it can be used to track users across websites.
              
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 2, 2, 2, 2, 2

result, different session: 4, 4, 4, 4, 4

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
fetch cache
When a resource is received via the Fetch API, it is frequently cached. That cache can potentially be abused for cross-site tracking.
              
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
font cache
Web fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.
              
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
iframe cache
An iframe is an element in a web page than allows websites to embed a second web page. Caching of this web page could be abused for cross-site tracking.
              
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
image cache
Caching of images in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.
              
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
indexedDB
The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
              
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_1p,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_1p,
409ba143-3756-4f1b-ae02-00cf293ba63f_1p,
c9708147-e276-4272-83fd-b1d199e502bd_1p,
302b0701-b3ea-4cfa-9137-acf825e86529_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
c5366d00-9adf-4038-a40e-30fa84214748_1p,
b9ab569e-b293-4a12-be90-a0ed912621d1_1p,
4667878f-16a5-4ecd-9e94-855e7e60726f_1p,
1c48fec6-4615-4891-ae9a-669a540891f0_1p

result, different session: undefined

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
10d65996-b480-4f3d-ba1a-82994148cebf_1p,
3548065b-9016-4d4b-b100-6ed874da1441_1p,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_1p,
15610b24-812c-4f95-a6ec-f725f40db44e_1p,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_1p,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_1p,
45cebc9a-6449-461a-9eaf-55fe8533da65_1p,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_1p,
5ed1f834-f5f0-4741-9db0-b54a51473811_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
5378069e-62e6-4c65-a4d7-c26e7103a34a_1p,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c_1p,
b4870a62-d8c7-4aa3-b869-a4b56ada1280_1p,
49049c26-be88-49c3-aacd-606f570a5052_1p,
f5068b02-e5d5-46da-b936-704909b924d9_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14_1p,
c5564407-7930-46c1-a37e-f1144b78e7ec_1p,
2f8f7e17-f84b-4431-b146-693b0fd9321f_1p,
36348409-e50d-4651-bda3-4959f87f3001_1p,
3c437474-8fee-4456-93f1-bc16a36d47d2_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d_1p,
7549b7b2-c691-4ec0-853b-002bc7356afd_1p,
20a4ff98-e9e0-46fc-b6fe-e284015063f6_1p,
f4f8644c-fd35-4941-8573-0f784f481de5_1p,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
1434311d-0f56-422e-84f7-59f56932dc61_1p,
2d6a5964-5158-4308-a47c-d338fc246ce0_1p,
820df721-3242-48ee-839b-39229099fc04_1p,
187af9d9-f96d-473d-a956-a5d2ff600513_1p,
dc205c47-3eeb-4d49-8103-0fc967659706_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
effad01a-1965-41dc-87ed-eec28f291b5f_1p,
a607723a-0d84-4334-958b-2c313172a3ba_1p,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_1p,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_1p,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
62097e54-7c8d-48ca-b419-51f0584c0e3e_1p,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5_1p,
11450af2-985c-44a8-9472-b73dc6ee5027_1p,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce_1p,
435bef94-82e0-4fa8-8fea-117f9e16b6a7_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_1p,
b8608586-7364-4679-a64d-3826b8686898_1p,
a82a08c9-d035-4122-b83c-42b933931544_1p,
3b7b0f8a-22d5-41b9-8443-475da21a220e_1p,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_1p,
42131e6f-5e91-454b-905d-4683d1f89cc0_1p,
124a771f-06af-4c5d-9669-4020fbcbe2ec_1p,
45b6e96f-1181-4133-ac15-69d0a3719c1a_1p,
438d0770-7624-4fa5-8c32-1623e842a289_1p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
localStorage
The localStorage API gives websites access to a key-value database that will remain available across visits. If the localStorage API is not partitioned or blocked, it can also be used to track users across websites.
              
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_1p,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_1p,
409ba143-3756-4f1b-ae02-00cf293ba63f_1p,
c9708147-e276-4272-83fd-b1d199e502bd_1p,
302b0701-b3ea-4cfa-9137-acf825e86529_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
c5366d00-9adf-4038-a40e-30fa84214748_1p,
b9ab569e-b293-4a12-be90-a0ed912621d1_1p,
4667878f-16a5-4ecd-9e94-855e7e60726f_1p,
1c48fec6-4615-4891-ae9a-669a540891f0_1p

result, different session: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
10d65996-b480-4f3d-ba1a-82994148cebf_1p,
3548065b-9016-4d4b-b100-6ed874da1441_1p,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_1p,
15610b24-812c-4f95-a6ec-f725f40db44e_1p,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_1p,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_1p,
45cebc9a-6449-461a-9eaf-55fe8533da65_1p,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_1p,
5ed1f834-f5f0-4741-9db0-b54a51473811_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
5378069e-62e6-4c65-a4d7-c26e7103a34a_1p,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c_1p,
b4870a62-d8c7-4aa3-b869-a4b56ada1280_1p,
49049c26-be88-49c3-aacd-606f570a5052_1p,
f5068b02-e5d5-46da-b936-704909b924d9_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14_1p,
c5564407-7930-46c1-a37e-f1144b78e7ec_1p,
2f8f7e17-f84b-4431-b146-693b0fd9321f_1p,
36348409-e50d-4651-bda3-4959f87f3001_1p,
3c437474-8fee-4456-93f1-bc16a36d47d2_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
e1747d7f-3cd7-4129-82f8-10ef548b3a1d_1p,
7549b7b2-c691-4ec0-853b-002bc7356afd_1p,
20a4ff98-e9e0-46fc-b6fe-e284015063f6_1p,
f4f8644c-fd35-4941-8573-0f784f481de5_1p,
2dd62ea8-c6c3-497f-93c3-0fdd6232e392_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
1434311d-0f56-422e-84f7-59f56932dc61_1p,
2d6a5964-5158-4308-a47c-d338fc246ce0_1p,
820df721-3242-48ee-839b-39229099fc04_1p,
187af9d9-f96d-473d-a956-a5d2ff600513_1p,
dc205c47-3eeb-4d49-8103-0fc967659706_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
effad01a-1965-41dc-87ed-eec28f291b5f_1p,
a607723a-0d84-4334-958b-2c313172a3ba_1p,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_1p,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_1p,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
62097e54-7c8d-48ca-b419-51f0584c0e3e_1p,
a8821c0e-37a5-4b1e-afc9-b63ce8542ce5_1p,
11450af2-985c-44a8-9472-b73dc6ee5027_1p,
3fa597cf-d3a9-48e4-9c2a-71c71e13fcce_1p,
435bef94-82e0-4fa8-8fea-117f9e16b6a7_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_1p,
b8608586-7364-4679-a64d-3826b8686898_1p,
a82a08c9-d035-4122-b83c-42b933931544_1p,
3b7b0f8a-22d5-41b9-8443-475da21a220e_1p,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_1p,
42131e6f-5e91-454b-905d-4683d1f89cc0_1p,
124a771f-06af-4c5d-9669-4020fbcbe2ec_1p,
45b6e96f-1181-4133-ac15-69d0a3719c1a_1p,
438d0770-7624-4fa5-8c32-1623e842a289_1p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
prefetch cache
A <link rel='prefetch'...> suggests to browsers they should fetch a resource ahead of time and cache it. But if browsers don't partition this cache, it can be used to track users across websites.
              
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Web SQL Database
The Web SQL Database is a deprecated web API for storing data in an SQL database.
              
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true

passed: undefined

test failed: false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated

result, different session: 
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
XMLHttpRequest cache
Similar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.
              
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Cross-session third-party tracking testsWhich browsers prevent third-party trackers from tracking you across browser sessions?
A common vulnerability of web browsers is that they allow third-party trackers to 'tag' your browser with some tracking data. This tag can be used to re-identify you when you return to a website you visited before. This category of leaks can be prevented by browser if they clean or isolate data between browser sessions. (In cases where a user has logged into a website or entered detailed information, it may be justifiable for a browser to retain information across sessions. These tests check when no such justification exists: when you have entered no significant information into a website, will the browser still retain data that allows you to be tracked across sessions?)
        
Alt-Svc
Alt-Svc allows the server to indicate to the web browser that a resource should be loaded on a different server. Because this is a persistent setting, it could be used to track users across websites if it is not correctly partitioned.
              
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h2, h2, h2, h2

result, different session: h2, h2, h2, h2

unsupported: true, true, true, true

passed: undefined

test failed: false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h2, h2, h2, h2, h2

result, different session: h3, h3, h3, h3, h3

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h2, h2, h2, h2, h2

result, different session: h2, h2, h2, h2, h2

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
CacheStorage
The Cache API is a content storage mechanism originally introduced to support ServiceWorkers. If the same Cache object is accessible to multiple websites, it can be abused to track users.
              
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.

result, different session: 
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.

result, different session: 
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.

unsupported: true, true, true, true

passed: undefined

test failed: false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
10d65996-b480-4f3d-ba1a-82994148cebf_3p,
3548065b-9016-4d4b-b100-6ed874da1441_3p,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_3p,
15610b24-812c-4f95-a6ec-f725f40db44e_3p,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_3p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_3p,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_3p,
45cebc9a-6449-461a-9eaf-55fe8533da65_3p,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_3p,
5ed1f834-f5f0-4741-9db0-b54a51473811_3p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
1434311d-0f56-422e-84f7-59f56932dc61_3p,
2d6a5964-5158-4308-a47c-d338fc246ce0_3p,
820df721-3242-48ee-839b-39229099fc04_3p,
187af9d9-f96d-473d-a956-a5d2ff600513_3p,
dc205c47-3eeb-4d49-8103-0fc967659706_3p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
effad01a-1965-41dc-87ed-eec28f291b5f_3p,
a607723a-0d84-4334-958b-2c313172a3ba_3p,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_3p,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_3p,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_3p

result, different session: 
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_3p,
b8608586-7364-4679-a64d-3826b8686898_3p,
a82a08c9-d035-4122-b83c-42b933931544_3p,
3b7b0f8a-22d5-41b9-8443-475da21a220e_3p,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_3p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }

result, same session: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_3p,
42131e6f-5e91-454b-905d-4683d1f89cc0_3p,
124a771f-06af-4c5d-9669-4020fbcbe2ec_3p,
45b6e96f-1181-4133-ac15-69d0a3719c1a_3p,
438d0770-7624-4fa5-8c32-1623e842a289_3p

result, different session: 
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
cookie (HTTP)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
              
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_3p_http,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_3p_http,
409ba143-3756-4f1b-ae02-00cf293ba63f_3p_http,
c9708147-e276-4272-83fd-b1d199e502bd_3p_http,
302b0701-b3ea-4cfa-9137-acf825e86529_3p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
c5366d00-9adf-4038-a40e-30fa84214748_3p_http,
b9ab569e-b293-4a12-be90-a0ed912621d1_3p_http,
4667878f-16a5-4ecd-9e94-855e7e60726f_3p_http,
1c48fec6-4615-4891-ae9a-669a540891f0_3p_http

result, different session: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_3p_http,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_3p_http,
45cebc9a-6449-461a-9eaf-55fe8533da65_3p_http,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_3p_http,
5ed1f834-f5f0-4741-9db0-b54a51473811_3p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
5378069e-62e6-4c65-a4d7-c26e7103a34a_3p_http,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c_3p_http,
b4870a62-d8c7-4aa3-b869-a4b56ada1280_3p_http,
49049c26-be88-49c3-aacd-606f570a5052_3p_http,
f5068b02-e5d5-46da-b936-704909b924d9_3p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14_3p_http,
c5564407-7930-46c1-a37e-f1144b78e7ec_3p_http,
2f8f7e17-f84b-4431-b146-693b0fd9321f_3p_http,
36348409-e50d-4651-bda3-4959f87f3001_3p_http,
3c437474-8fee-4456-93f1-bc16a36d47d2_3p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }

read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
cookie (JS)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
              
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_3p_js,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_3p_js,
409ba143-3756-4f1b-ae02-00cf293ba63f_3p_js,
c9708147-e276-4272-83fd-b1d199e502bd_3p_js,
302b0701-b3ea-4cfa-9137-acf825e86529_3p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
c5366d00-9adf-4038-a40e-30fa84214748_3p_js,
b9ab569e-b293-4a12-be90-a0ed912621d1_3p_js,
4667878f-16a5-4ecd-9e94-855e7e60726f_3p_js,
1c48fec6-4615-4891-ae9a-669a540891f0_3p_js

result, different session: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_3p_js,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_3p_js,
45cebc9a-6449-461a-9eaf-55fe8533da65_3p_js,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_3p_js,
5ed1f834-f5f0-4741-9db0-b54a51473811_3p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
5378069e-62e6-4c65-a4d7-c26e7103a34a_3p_js,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c_3p_js,
b4870a62-d8c7-4aa3-b869-a4b56ada1280_3p_js,
49049c26-be88-49c3-aacd-606f570a5052_3p_js,
f5068b02-e5d5-46da-b936-704909b924d9_3p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14_3p_js,
c5564407-7930-46c1-a37e-f1144b78e7ec_3p_js,
2f8f7e17-f84b-4431-b146-693b0fd9321f_3p_js,
36348409-e50d-4651-bda3-4959f87f3001_3p_js,
3c437474-8fee-4456-93f1-bc16a36d47d2_3p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }

read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
CookieStore
The Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.
              
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_3p,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_3p,
409ba143-3756-4f1b-ae02-00cf293ba63f_3p,
c9708147-e276-4272-83fd-b1d199e502bd_3p,
302b0701-b3ea-4cfa-9137-acf825e86529_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
c5366d00-9adf-4038-a40e-30fa84214748_3p,
b9ab569e-b293-4a12-be90-a0ed912621d1_3p,
4667878f-16a5-4ecd-9e94-855e7e60726f_3p,
1c48fec6-4615-4891-ae9a-669a540891f0_3p

result, different session: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_3p,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_3p,
45cebc9a-6449-461a-9eaf-55fe8533da65_3p,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_3p,
5ed1f834-f5f0-4741-9db0-b54a51473811_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }

read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
CSS cache
CSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.
              
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_8952647724672862,
fake_20097128890019778,
fake_9955604508249254,
fake_45779720261544066,
fake_9836305411626134

result, different session: 
fake_681755188132545,
fake_699144512108391,
fake_14212293051211145,
fake_10768344389385986,
fake_0968300847501451

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_008590936143714867,
fake_5532568450793616,
fake_07005259816528042,
fake_14319390816014566

result, different session: 
fake_9057684781696611,
fake_500736273008989,
fake_4586419047242085,
fake_2503738212053712

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_5770882675425761,
fake_13204785233031835,
fake_9359594202895538,
fake_6217383465236941,
fake_17451792016963297

result, different session: 
fake_12157203387461823,
fake_4046140698978238,
fake_9518012112573306,
fake_19475029480252637,
fake_5102209423765538

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_32851660072013544,
fake_3051527013160491,
fake_3904714211593612,
fake_19035274760523468,
fake_09978138154303773

result, different session: 
fake_4330708717598015,
fake_5269523403448553,
fake_3537075816179973,
fake_4408850650027081,
fake_29594090928560934

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_8443698887556372,
fake_9532371258654355,
fake_1391291592641246,
fake_8861192934392339,
fake_06188621881607004

result, different session: 
fake_2642521236188775,
fake_8939138006324174,
fake_7197087109174085,
fake_5926235641841606,
fake_056443009915675635

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_037427180408714955,
fake_07072453963967495,
fake_3626955881220988,
fake_8178270997607224,
fake_3006260914539194

result, different session: 
fake_4742431439983603,
fake_9434205132224716,
fake_6270344728562345,
fake_5661787118850978,
fake_4848507013482244

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_5815902131228692,
fake_054144253838437795,
fake_5078414127412034,
fake_17334227725369344,
fake_9493052563641391

result, different session: 
fake_17514920600847228,
fake_6836274748164441,
fake_7770282206599399,
fake_5921282753578354,
fake_19157215810545258

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_5793760670549954,
fake_9611529325464225,
fake_6942550022415204,
fake_2740990163913173,
fake_5956245490104564

result, different session: 
fake_8186648748461609,
fake_6649026809988554,
fake_32037961697614037,
fake_4253392395588902,
fake_9988850610854219

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_46196422326223185,
fake_516409155621625,
fake_995013565562398,
fake_9165538501028956,
fake_3710741646869269

result, different session: 
fake_46196422326223185,
fake_516409155621625,
fake_995013565562398,
fake_9165538501028956,
fake_3710741646869269

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_5596148033502149,
fake_004698747848437268,
fake_5882469708520364,
fake_9146758480194903,
fake_46159832451021177

result, different session: 
fake_4455718633169463,
fake_5493156813836595,
fake_638899430562073,
fake_7161498887680784,
fake_2744722840517837

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_3009863901641123,
fake_3745721469787717,
fake_10731841396228248,
fake_26044806541947296,
fake_39606305301097966

result, different session: 
fake_6975315980380823,
fake_9149298130646606,
fake_08057527723955205,
fake_8409220025790809,
fake_9822404752492309

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }

read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }

result, same session: 
fake_31332679937789476,
fake_5878771839536598,
fake_7269401996100475,
fake_7505667326698549,
fake_3086707376315987

result, different session: 
fake_5216678355932145,
fake_48439169460376585,
fake_5755296577873235,
fake_37833356283566655,
fake_12882819966062553

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
favicon cache
A favicon is an icon that represents a website, typically shown in browser tab and bookmarks menu. If the favicon cache is not partitioned, it can be used to track users across websites.
              
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 1, 2, 2

unsupported: false, false, false, false, false

passed: true, true, false, true, true

test failed: false, false, false, false, false
Passed
write: (key) => key

read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }

result, same session: 2, 2, 2, 2, 2

result, different session: 4, 4, 4, 4, 4

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
fetch cache
When a resource is received via the Fetch API, it is frequently cached. That cache can potentially be abused for cross-site tracking.
              
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }

read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
font cache
Web fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.
              
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }

read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
iframe cache
An iframe is an element in a web page than allows websites to embed a second web page. Caching of this web page could be abused for cross-site tracking.
              
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })

read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
image cache
Caching of images in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.
              
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })

read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
indexedDB
The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
              
Unsupported
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

result, different session: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

result, different session: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

unsupported: true, true, true, true

passed: undefined

test failed: false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
10d65996-b480-4f3d-ba1a-82994148cebf_3p,
3548065b-9016-4d4b-b100-6ed874da1441_3p,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_3p,
15610b24-812c-4f95-a6ec-f725f40db44e_3p,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_3p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_3p,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_3p,
45cebc9a-6449-461a-9eaf-55fe8533da65_3p,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_3p,
5ed1f834-f5f0-4741-9db0-b54a51473811_3p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
5378069e-62e6-4c65-a4d7-c26e7103a34a_3p,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c_3p,
b4870a62-d8c7-4aa3-b869-a4b56ada1280_3p,
49049c26-be88-49c3-aacd-606f570a5052_3p,
f5068b02-e5d5-46da-b936-704909b924d9_3p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14_3p,
c5564407-7930-46c1-a37e-f1144b78e7ec_3p,
2f8f7e17-f84b-4431-b146-693b0fd9321f_3p,
36348409-e50d-4651-bda3-4959f87f3001_3p,
3c437474-8fee-4456-93f1-bc16a36d47d2_3p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
1434311d-0f56-422e-84f7-59f56932dc61_3p,
2d6a5964-5158-4308-a47c-d338fc246ce0_3p,
820df721-3242-48ee-839b-39229099fc04_3p,
187af9d9-f96d-473d-a956-a5d2ff600513_3p,
dc205c47-3eeb-4d49-8103-0fc967659706_3p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
effad01a-1965-41dc-87ed-eec28f291b5f_3p,
a607723a-0d84-4334-958b-2c313172a3ba_3p,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_3p,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_3p,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_3p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_3p,
b8608586-7364-4679-a64d-3826b8686898_3p,
a82a08c9-d035-4122-b83c-42b933931544_3p,
3b7b0f8a-22d5-41b9-8443-475da21a220e_3p,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_3p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_3p,
42131e6f-5e91-454b-905d-4683d1f89cc0_3p,
124a771f-06af-4c5d-9669-4020fbcbe2ec_3p,
45b6e96f-1181-4133-ac15-69d0a3719c1a_3p,
438d0770-7624-4fa5-8c32-1623e842a289_3p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
localStorage
The localStorage API gives websites access to a key-value database that will remain available across visits. If the localStorage API is not partitioned or blocked, it can also be used to track users across websites.
              
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
bcebd4c7-d7a9-402d-baaa-cc2ec92a1441_3p,
230d0662-cf1b-4545-b3d6-f79a5fa51fce_3p,
409ba143-3756-4f1b-ae02-00cf293ba63f_3p,
c9708147-e276-4272-83fd-b1d199e502bd_3p,
302b0701-b3ea-4cfa-9137-acf825e86529_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
c5366d00-9adf-4038-a40e-30fa84214748_3p,
b9ab569e-b293-4a12-be90-a0ed912621d1_3p,
4667878f-16a5-4ecd-9e94-855e7e60726f_3p,
1c48fec6-4615-4891-ae9a-669a540891f0_3p

result, different session: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
10d65996-b480-4f3d-ba1a-82994148cebf_3p,
3548065b-9016-4d4b-b100-6ed874da1441_3p,
b2a2b327-6c81-459d-9d8a-27cf71cd116d_3p,
15610b24-812c-4f95-a6ec-f725f40db44e_3p,
a0ceb013-6a3e-4f07-848d-65f91ed6a4f7_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
eebe4c45-6842-4d19-ac58-8ba38a062639_3p,
4fca741f-dfdb-47b1-87a7-5a7c11f33dfd_3p,
45cebc9a-6449-461a-9eaf-55fe8533da65_3p,
16c9bfb5-3a44-4efa-ab9d-5ff7f7b2dbbd_3p,
5ed1f834-f5f0-4741-9db0-b54a51473811_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
5378069e-62e6-4c65-a4d7-c26e7103a34a_3p,
3d7c8a38-b36d-4eff-a5f9-8d6e16db6c5c_3p,
b4870a62-d8c7-4aa3-b869-a4b56ada1280_3p,
49049c26-be88-49c3-aacd-606f570a5052_3p,
f5068b02-e5d5-46da-b936-704909b924d9_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
79e1ab5c-4542-4002-b9b5-b658d58b9a14_3p,
c5564407-7930-46c1-a37e-f1144b78e7ec_3p,
2f8f7e17-f84b-4431-b146-693b0fd9321f_3p,
36348409-e50d-4651-bda3-4959f87f3001_3p,
3c437474-8fee-4456-93f1-bc16a36d47d2_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
1434311d-0f56-422e-84f7-59f56932dc61_3p,
2d6a5964-5158-4308-a47c-d338fc246ce0_3p,
820df721-3242-48ee-839b-39229099fc04_3p,
187af9d9-f96d-473d-a956-a5d2ff600513_3p,
dc205c47-3eeb-4d49-8103-0fc967659706_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
effad01a-1965-41dc-87ed-eec28f291b5f_3p,
a607723a-0d84-4334-958b-2c313172a3ba_3p,
f8cfbf23-092f-479f-934f-6fac9e8b1d60_3p,
964ddb73-cf83-46d8-af09-ed55dbe9e73a_3p,
17c4b94d-fcd4-44b8-a08d-183aaa204c37_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
d50f04af-21bb-4e36-92bb-a8b8e596a3a5_3p,
b8608586-7364-4679-a64d-3826b8686898_3p,
a82a08c9-d035-4122-b83c-42b933931544_3p,
3b7b0f8a-22d5-41b9-8443-475da21a220e_3p,
6ebce8cd-2bd6-41d5-b91c-77a52c3f5322_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
9e3afe05-7672-45ba-8746-30b66be3fdd1_3p,
42131e6f-5e91-454b-905d-4683d1f89cc0_3p,
124a771f-06af-4c5d-9669-4020fbcbe2ec_3p,
45b6e96f-1181-4133-ac15-69d0a3719c1a_3p,
438d0770-7624-4fa5-8c32-1623e842a289_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
prefetch cache
A <link rel='prefetch'...> suggests to browsers they should fetch a resource ahead of time and cache it. But if browsers don't partition this cache, it can be used to track users across websites.
              
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

result, different session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Web SQL Database
The Web SQL Database is a deprecated web API for storing data in an SQL database.
              
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true

passed: undefined

test failed: false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated

result, different session: 
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated,
Error: Web SQL is deprecated

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!window.openDatabase) {
        throw new Error("gported");
      }
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let tx = new Promise((resolve) => database.transaction(tx => {
        tx.executeSql(
          `CREATE TABLE IF NOT EXISTS cache(
             id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
             name TEXT NOT NULL,
             value TEXT NOT NULL,
             UNIQUE (name)
           )`,
          [], (tx, rs) => {}, (tx, err) => {});
        tx.executeSql(
          `INSERT OR REPLACE INTO cache(name, value)
           VALUES(?, ?)`,
          ["secret", key], (tx, rs) => {}, (tx, rs) => {});
      }));
    }

read: async () => {
      let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024);
      let result = await new Promise((resolve, reject) => database.transaction(tx => {
        tx.executeSql(
          "SELECT value FROM cache WHERE name=?",
          ["secret"],
          (tx, rs) => resolve(rs),
          (tx, err) => reject(err));
      }));
      return result.rows.item(0).value;
    }

result, same session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

result, different session: 
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function,
Error: window.openDatabase is not a function

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
XMLHttpRequest cache
Similar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.
              
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 1, 1, 1, 1

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false