Nightly private modes

(default settings)
brave logo
brave
1.64

private
brave logo
brave
1.64

Tor
chrome logo
chrome
123.0

private
edge logo
edge
123.0

private
firefox logo
firefox
123.0a1

private
opera logo
opera
108.0

private
safari logo
safari
17.4

private
tor logo
tor
13.5a4

private
vivaldi logo
vivaldi
6.6

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
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

result, different first party: h2

unsupported: true

passed: undefined

test failed: 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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

result, different first party: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

result, different first party: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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: 
2a285f58-9c50-403e-8221-1ead8361d1e2,
47c67078-5a7f-4427-9431-1bab6425cca5,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
94e1226f-d529-4585-8f88-ba099c24ddf0,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

result, different first party: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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: Error: Load failed

result, different first party: Error: Load failed

unsupported: false

passed: undefined

test failed: true
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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa,
2e3531e6-80d7-404c-9fa0-7f5d66bed947,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5

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.

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

result, different first party: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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: 
2a285f58-9c50-403e-8221-1ead8361d1e2,
47c67078-5a7f-4427-9431-1bab6425cca5,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
94e1226f-d529-4585-8f88-ba099c24ddf0,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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: Error: no BroadcastChannel message

result, different first party: Error: no BroadcastChannel message

unsupported: false

passed: undefined

test failed: true
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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa,
2e3531e6-80d7-404c-9fa0-7f5d66bed947,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5

result, different first party: 
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

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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')

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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: 
2a285f58-9c50-403e-8221-1ead8361d1e2,
47c67078-5a7f-4427-9431-1bab6425cca5,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
94e1226f-d529-4585-8f88-ba099c24ddf0,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

result, different first party: 
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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: Error: undefined is not an object (evaluating 'cacheKeys[0].url')

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

unsupported: false

passed: undefined

test failed: true
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.

result, different first party: 
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

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 first party: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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: 
b732c02d-def9-4b33-929a-c76b16c9b345_http,
625a4d67-4292-4f87-8ea0-918f16d89cb3_http,
2424de9e-f493-4717-8424-72052e2d4a16_http,
54a72806-2901-4b14-989b-ecb256c7ab1a_http,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_http,
d9589982-3c98-42d3-8409-24396a6b342c_http,
0a98c970-990f-4333-8b8f-7cc3070d77e1_http,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec_http,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10_http,
a69f17a8-a2a8-40d5-875f-dcf03f303c03_http,
8b71f061-2045-4416-b41a-16ec6cb2c36a_http,
843cbdf0-de18-402d-b021-01d864b097b2_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_http,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_http,
88792acc-7d87-4949-8369-3c459089a332_http,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_http,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_http

result, different first party: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_http,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_http,
88792acc-7d87-4949-8369-3c459089a332_http,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_http,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_http,
47c67078-5a7f-4427-9431-1bab6425cca5_http,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_http,
94e1226f-d529-4585-8f88-ba099c24ddf0_http,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb_http,
002305ff-951e-46fd-98c7-cde9b221fd6f_http,
92d55579-f8bd-4d38-b97d-2c3b805105d3_http,
96170814-9d74-4f59-a908-f165312ec7a0_http,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d_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: null

result, different first party: null

unsupported: false

passed: undefined

test failed: true
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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa_http,
2e3531e6-80d7-404c-9fa0-7f5d66bed947_http,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6_http,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5_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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc_http,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d_http,
46c52812-ac93-4f36-b9a2-9ac351087915_http,
7e1a42d0-d90c-4adf-bace-00066fabf354_http,
ddac5d3a-603d-41cd-b9ae-7391f9304303_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: 
b732c02d-def9-4b33-929a-c76b16c9b345_js,
625a4d67-4292-4f87-8ea0-918f16d89cb3_js,
2424de9e-f493-4717-8424-72052e2d4a16_js,
54a72806-2901-4b14-989b-ecb256c7ab1a_js,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_js,
d9589982-3c98-42d3-8409-24396a6b342c_js,
0a98c970-990f-4333-8b8f-7cc3070d77e1_js,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec_js,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10_js,
a69f17a8-a2a8-40d5-875f-dcf03f303c03_js,
8b71f061-2045-4416-b41a-16ec6cb2c36a_js,
843cbdf0-de18-402d-b021-01d864b097b2_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_js,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_js,
88792acc-7d87-4949-8369-3c459089a332_js,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_js,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_js

result, different first party: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_js,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_js,
88792acc-7d87-4949-8369-3c459089a332_js,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_js,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_js,
47c67078-5a7f-4427-9431-1bab6425cca5_js,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_js,
94e1226f-d529-4585-8f88-ba099c24ddf0_js,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb_js,
002305ff-951e-46fd-98c7-cde9b221fd6f_js,
92d55579-f8bd-4d38-b97d-2c3b805105d3_js,
96170814-9d74-4f59-a908-f165312ec7a0_js,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d_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: null

result, different first party: null

unsupported: false

passed: undefined

test failed: true
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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa_js,
2e3531e6-80d7-404c-9fa0-7f5d66bed947_js,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6_js,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5_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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc_js,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d_js,
46c52812-ac93-4f36-b9a2-9ac351087915_js,
7e1a42d0-d90c-4adf-bace-00066fabf354_js,
ddac5d3a-603d-41cd-b9ae-7391f9304303_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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

result, different first party: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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
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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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

result, different first party: Error: Unsupported

unsupported: true

passed: undefined

test failed: 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

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

unsupported: true, true, true, true

passed: undefined

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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_4387047331200309,
fake_3333929517599763,
fake_7462524187704602,
fake_8661642810068664,
fake_10933705362455282

result, different first party: 
fake_022953251797426688,
fake_409646978621381,
fake_32822453312075783,
fake_9562745122924257,
fake_03641087530856546

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_2908559541142639,
fake_9094658418405555,
fake_3743438840758513,
fake_47072386155657386

result, different first party: 
fake_6641110910416368,
fake_13186534042988662,
fake_2417536266909237,
fake_6452118677162006

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_1240704303857012,
fake_3965609175475633,
fake_527540503797659,
fake_01266134169222255,
fake_09428857298724802

result, different first party: 
fake_3304276788322653,
fake_941290989913083,
fake_7483507139228456,
fake_5447565604161504,
fake_3817606520740935

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_40703661426214666,
fake_9711782380793108,
fake_228787844936033,
fake_5076324192148918,
fake_676176624741804

result, different first party: 
fake_2912724291381472,
fake_45380294400839394,
fake_34041243664740284,
fake_7703398523604041,
fake_9052243385853536

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_36303236021420004,
fake_7015799694610856,
fake_6340548966784707,
fake_933380803790191,
fake_13133592218813428

result, different first party: 
fake_6425788391203793,
fake_44919712446252547,
fake_40361986022704976,
fake_4725961853056855,
fake_8354750042651138

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_41797222054555405,
fake_7457232882015754,
fake_7502043402167329,
fake_8388651968117744,
fake_0700740086010323

result, different first party: 
fake_293134728935593,
fake_3394672105101948,
fake_5836414906354543,
fake_4497003489345419,
fake_697662263580082

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_6542878857114802

result, different first party: fake_41207962068915194

unsupported: false

passed: true

test failed: 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_10342202713321225,
fake_7783450516438073,
fake_16873489850067647,
fake_545042716432165

result, different first party: 
fake_3658695390103033,
fake_29990221004930495,
fake_7850699784009467,
fake_7586108420143645

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_16837574921574716,
fake_5213658999390711,
fake_1314816344027272,
fake_18418765538791715,
fake_8021981100190172

result, different first party: 
fake_6300293448885705,
fake_7379813939890523,
fake_050215156266328664,
fake_4525111550524541,
fake_7247027565765087

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

result, different first party: 2

unsupported: false

passed: true

test failed: 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: 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: 2

result, different first party: 3

unsupported: false

passed: true

test failed: 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
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: 2

result, different first party: 3

unsupported: false

passed: true

test failed: 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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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
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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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

result, different first party: Error: Unsupported

unsupported: true

passed: undefined

test failed: 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

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

unsupported: true, true, true, true

passed: undefined

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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: 
2a285f58-9c50-403e-8221-1ead8361d1e2,
47c67078-5a7f-4427-9431-1bab6425cca5,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
94e1226f-d529-4585-8f88-ba099c24ddf0,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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: 

result, different first party: 

unsupported: false

passed: undefined

test failed: true
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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa,
2e3531e6-80d7-404c-9fa0-7f5d66bed947,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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: 
2a285f58-9c50-403e-8221-1ead8361d1e2,
47c67078-5a7f-4427-9431-1bab6425cca5,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
94e1226f-d529-4585-8f88-ba099c24ddf0,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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: 

result, different first party: 

unsupported: false

passed: undefined

test failed: true
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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa,
2e3531e6-80d7-404c-9fa0-7f5d66bed947,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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: 
1ea7f812d4454ddddeada3dd5bcead0b,
5e73d5d602535fdec721b1f67c08b6e3,
fdbdc1b02e2374e1a2425582f5f631f0,
bc590b11620bc24808b1e19a142738ed,
f71f61e454ee8579a9e6aa093157fe00

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: 
5f972e4962da12486cc52777c76f547c,
820f96e349241a0b37626a7af14743f7,
043aa3cce6368eadbea8591f4038f56f,
dbacdd3bc1d8efe52670f1b268375cef,
546c7e3547d15e498fbb1dba13d3d440

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: 
4b69d7efa12bb72a7a1ef5123d9a555a,
3a1fd0f3d0143f6ca196b7f1463a0c4d,
ea28fc5744aa28a380f8e6d148bd1867,
db921f2878262e809229502cb30a9f25,
00d1aa7fabbfc6a7eb8f761b1f647898

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: 
4025415691b25010f9d8672a7afe2735,
0ac524883e3483458935b38d2f1f081f,
6fb6d0b927370b62054d95908cfd11f3,
3d3a0366a256df1dbcf2762c8ff3d99e,
a5e2b527d01ed039ef7918329f235c64

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: 
987c4eba7fe4037146e199a97810f7f5,
1eb482408d64cace984d89b92ed19986,
9b4b616d7ef10ed60b3509005f0af0a4,
de0a02d40249a9b52ad673862e075041,
29db1a00669402e3d5ddeb1543056963

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

passed: undefined

test failed: 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: 
64fc521b6b9101e0b47b5a88a1513e85,
56ae35e0a44a93774754128946d4419a,
576d6b629387fc1ee19a1d235314c2a3,
f4b110943075ce3e6f3d6326b3b43740,
8e9c2de92f25cd62536d339330f27418

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
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

result, different first party: Used http

unsupported: false

passed: true

test failed: 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
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
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

result, different first party: Used http

unsupported: false

passed: true

test failed: 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
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: 2

result, different first party: 3

unsupported: false

passed: true

test failed: 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
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: 2

result, different first party: 3

unsupported: false

passed: true

test failed: 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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

result, different first party: 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 first party: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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: 
2a285f58-9c50-403e-8221-1ead8361d1e2,
47c67078-5a7f-4427-9431-1bab6425cca5,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
94e1226f-d529-4585-8f88-ba099c24ddf0,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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: undefined

result, different first party: undefined

unsupported: false

passed: undefined

test failed: true
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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa,
2e3531e6-80d7-404c-9fa0-7f5d66bed947,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5

result, different first party: 
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

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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: 
2a285f58-9c50-403e-8221-1ead8361d1e2,
47c67078-5a7f-4427-9431-1bab6425cca5,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
94e1226f-d529-4585-8f88-ba099c24ddf0,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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: null

result, different first party: null

unsupported: false

passed: undefined

test failed: true
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same first party: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa,
2e3531e6-80d7-404c-9fa0-7f5d66bed947,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5

result, different first party: 
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

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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')

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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: 
2a285f58-9c50-403e-8221-1ead8361d1e2,
47c67078-5a7f-4427-9431-1bab6425cca5,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
94e1226f-d529-4585-8f88-ba099c24ddf0,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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: Error: undefined is not an object (evaluating 'queryResult.held[0].name')

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

unsupported: false

passed: undefined

test failed: true
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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa,
2e3531e6-80d7-404c-9fa0-7f5d66bed947,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5

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

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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
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

result, different first party: Error: No requests received

unsupported: true

passed: undefined

test failed: 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

result, different first party: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true

passed: undefined

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
script cache
Caching of scripts 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

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

result, same first party: 2

result, different first party: 3

unsupported: false

passed: true

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

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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
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: , , , , 

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: ServiceWorker registration failed,
Error: ServiceWorker registration failed,
,
Error: ServiceWorker registration failed

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: can't access property "register",
navigator.serviceWorker is undefined,
Error: can't access property "register",
navigator.serviceWorker is undefined,
Error: can't access property "register",
navigator.serviceWorker is undefined,
Error: can't access property "register",
navigator.serviceWorker is undefined,
Error: can't access property "register",
navigator.serviceWorker is undefined

result, different first party: 
Error: can't access property "register",
navigator.serviceWorker is undefined,
Error: can't access property "register",
navigator.serviceWorker is undefined,
Error: can't access property "register",
navigator.serviceWorker is undefined,
Error: can't access property "register",
navigator.serviceWorker is undefined,
Error: can't access property "register",
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

passed: undefined

test failed: 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

result, different first party: 
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

passed: undefined

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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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: 
2a285f58-9c50-403e-8221-1ead8361d1e2,
47c67078-5a7f-4427-9431-1bab6425cca5,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
94e1226f-d529-4585-8f88-ba099c24ddf0,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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 {
        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: Error: Unsupported

result, different first party: Error: Unsupported

unsupported: true

passed: undefined

test failed: 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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa,
2e3531e6-80d7-404c-9fa0-7f5d66bed947,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5

result, different first party: 
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

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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: 
21860f0c74139790d85280c4c703d810497ebd3dbb9867b8e8cdf1227efaf7f8,
7f09bcbc6a2745fc34a2d08ab1340581841db78c78e4685ea195388ed166c254,
eb14bcf3a73a8cce54447e488a986b4408f29671eedad638a3d3486c78df2b35,
d18ec083398cc6b3ecd0b58bad972d5c2293aa9da7e9d9f10122c8da56adb508,
7403d898f9eb3e5f062f518b4e4037dd0a50202db43ad01df603b0dd6910b4a0

result, different first party: 
7c7f395524381e02c35c1698d3c30f03e530e8facb41e53414493c16c93dba59,
ababad13ff523a0faa4db6a703d2b78527cac966c6a47cd5f70adeb8f3b4a165,
cd2af6e10ed6d0e31599f03cbdaf2a9fa1880fbd57812db73ccac27ceae3ef2c,
b2216cc1f18c55fcb70304beff5a3b8803934a6034419746a0e48c04c7815a61,
38a48f749d95f9943eb7ae7f8e179f17475567e837469816bbeeed360909fce5

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: 
8feef26d5c9427ae9620db4da6bcb55d2670e2e642939690d6ff57a5a9493bf9,
72a34f6dd6c799de56096336d496a50bd97f234685e85ad074b15a1cdabde1f4,
b0e0bdf729c2be5ef429a92520c6a41bc51394e18a73869df491e93a4fed71fe,
11a259d71b772a12acbba9adf27d4b3ef21e25bb14d8db1a4e59c5b48d36c428

result, different first party: 
8544f48c4fd352b679bbd1c023053dd00e939b4baf7d6f406389b9c088ff6bee,
46ecc05e356becdb72005087fb9ff311e8cb0ea8406a58c2cb742da8a77d7054,
9ade4173d41cb27d8ec03808fe87970414ac5d9d22e3b1418bbf64bc42906844,
c1fae2a484a00e799482ade2dc9d8e87da4f87a4143e62c2e2a62c033d1abffd

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: 
402b25b4fb0f4eff49062a64eb2a73da6f00c162ca18710ed4501ca96ac9fb87,
f7aedace172a2c6f44357df2e43ff118984b3263d50c5c59ef2d81e707e9f60c,
b0a5c658affa2c84f90346789fa083a6f80447eebe79045d8f55ac21ce860e50,
88ca432dc359bee8ddc5526b8871b7709a6084aedf796936a3e731550fcb1b9b,
d2e602c2b171330001254373daf885acdd46ac7f3a5f09c532504ff769fa4f33

result, different first party: 
900c3458e1b37bebdc4da56ee2e9cf39f1deab5f328c0db2aede3c77c6c7109c,
700f52660841128cbba88f12d2710a7b3045641a86e6add58133e515eaa67551,
e42e00761c6c8db56427dacc287d715baaf86b1c2e601b64ae4f6fa283822056,
8aa8061ac2090cb704e67ec543fc524bb8d234aa2e2434ec6c37c4436553954f,
ed4fabced2ae5f2608dd7932e984fd81aafb59036e0ddb13385fd9c263c8332c

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: 
5e989db1cd2b3bf97b9e92c67305fb292120257509f1a1661d7332c3dd11925c,
ce94e2f1524dcafe70888af021a42171eec97de384c18643c17f661f3433aa2b,
a7ddf221a117d1c81af0ec7d02a4cd8a742615ce98a00864e3df85873ef98617,
293f4617818d2137ffb40eea39c5ea0afe8d52f1500bf14b72555e227d0ef4c6,
93d530c44daa88a8eaacee12a5474c4ae43a00c21b29d43be5b62be81ca38d5b

result, different first party: 
2cd0514f8bd0f59bcde70f5c2632657ebd0ca2bd8ca301671b803e9871d2e9a7,
021c7184e5cda1d346cf89e267cdf98e02b093777fe70448eff260ded276e86d,
925dfcb9665514d243fb3ba0504999f193794f782106225e0c5d0ea515faadd0,
9e8037c26853d33ce704f86e4b8bc12b66b77d7ad7713301c58bc3ebb75c7258,
6722c0f7beafbf75a09022e5ce05e8f6f1b09fc7e40e2622a40fb3cf81514cf9

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: 
7966d4d36dc929ecb5c19eaeaef8e58fff848bdd73856a84962233b4328c0554,
de8a69b8961eac9718bde1a2e690de5781b0a05a8cf3e114d2791639fb1fb493,
8a77915620c1f2bbe4b4b6bd6a918f5b3941f0aeb593802e5090910189005616,
11c4ccaa8cb62e4d438a4b5e7a615bd28f150ff71cbb48c70113eb8cf9b93e94,
7cf1a346b26576775910ed1d516feb3761a69fcece5b1016e76d0a26c2f4e8ab

result, different first party: 
3052f2b1af2c400b21bfb7f49f2066a22a4e87d4d918470477b1087943bf3fa3,
63b461da856e4b64217c856cf8855fc60fd3cb3f15af5bb32330488c34303956,
cfd2954eba909f3485faf63e5a2aa7835726e60ac64079ea11d607acc30d48ac,
4431b8a6c75e905cbaa24986e7422106c0c596d9a859c0122ec80aebda9af247,
24ee7deecced08128cc05013d96f0782dff70fb665852a029e3f2d10daf4ee93

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: 
3a820dee3292ee1fc7dff8a60e278a264190a098963fe5efec31985d3fc2856a,
dabfc99105ae0622891d05383846f16a0fb2db9b604021546c7e8ab6f44489d2,
196ca248bd62faec782d3dbd48a421572381a2103009a85de6c648f414cb0130,
5b0fa32380f4aced3fa4c19b22dfb316d155ba3794a3211a6b4853c198264f90,
ae55e0dc326b0f3c3f477c2a6452e2ab6cffbadb6d014989e7e78b6c471b0bda

result, different first party: 
b42751868c20d3212ad3d9f08a69107804cb1ad318890b109d99f6d3455e22c7,
d341d7deb8fa425fd5eac6ab32f6b3f1fd1152d3f81bc2aac45c49e2e7c1f1d8,
9f1207fef70204b27f9c09d8bc4c4bef1d63b5f40770046b83c584c838218e1b,
cb3198b0488b18ce14fe016f2d203d4475eeabba7cd4b05349097d065612f866,
211d4c5e5f51835b1fbbef6a9ffdf09fa174b6fafb59dbc6472a3a92588d4d36

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: c9e4f9006639deb531e63bff497a160e4357d3f2221daf486ceed78421fdd5b2

result, different first party: a4bb4ca62e827c71c604601e2490d270e17184df8390621686c66f32b9f41697

unsupported: false

passed: true

test failed: 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: 
80e3c6ca1fdc71bf723fc5533e9a6d7e957fd8ed01eb9834616a04352cc1323b,
0d0eca89aa9bf15a3e0eea98c684514b9793a2a90585689933b2cdf9e391cd4a,
ece28f0bdc374938dc3bbd82c51950a8807090f54c747fc5c8abf62d290af5ba,
21e4971cd81d983dc8dd19c18e3aa62d001633a552fdca93589a3a027a758fca

result, different first party: 
5a1b8b25dadf1b9f86fb4937050219729e58dbcde731169cb5209f4b6ca44463,
ae7a672b36660ee96e83f4c1d79c09850863a9f48edd692e1aee90c0a8b7d450,
a505ac625f567c97a60e232e80550230334cd8e80431d9c87558eb8a7f0186f8,
3abf885c1a05ae032c17e7f2d8ac433c47437727fc1c26f358d50108980b50d7

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: 
4659be44a9fb36d3e637d837e97dc637dfd935923d80b178f6b077b0001885d9,
47e74d37bc31af599a9bf4f18fd072a8d01b9fc2c47c26000b29198099f99ab0,
37a9c05fe56d96c9a3d75098f8a599d843759450500a9daec7e93cccadac823f,
2e39e20cd6885e6fc779d0af48848e10637d609ca87566df1a93e7e4258997cb,
3dee9df3be33089f65fc86cdf4e663621ce4a4fb49ee9a02df9464fa96a02c94

result, different first party: 
0b6cb336d2961b9ac31dc7b14c46795608ffb6f22136bdb434b45ab9ec4b681b,
d2c2ea57f477feecdac812a89ab39fea22781e7e7c1c1592162c71937cc12106,
d95158388d093146caff632e2ee00c8e3cc09c7b21ebab4344bd9d75fa0ec3ee,
10ee74af6fa234ef828f5e6f4e8acf34585458cc3e0182b059c6e4d24e9a38eb,
0c8d7117be4f71f1ea37069d92bd5eb6fa006258c267cb6ba1b8c5f891847458

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: Web SQL is deprecated

result, different first party: Error: Web SQL is deprecated

unsupported: false

passed: undefined

test failed: 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
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: 2

result, different first party: 3

unsupported: false

passed: true

test failed: 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
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
Passed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

result, same first party: https://test-pages.privacytests2.org/

result, different first party: 

unsupported: false

passed: true

test failed: 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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345,
625a4d67-4292-4f87-8ea0-918f16d89cb3,
2424de9e-f493-4717-8424-72052e2d4a16,
54a72806-2901-4b14-989b-ecb256c7ab1a,
0a56a84e-07c9-460f-bc20-624f86de53e5

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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0,
d9589982-3c98-42d3-8409-24396a6b342c,
0a98c970-990f-4333-8b8f-7cc3070d77e1,
d24185c6-d67c-4c2a-a9a8-7c4080072888

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
a69f17a8-a2a8-40d5-875f-dcf03f303c03,
8b71f061-2045-4416-b41a-16ec6cb2c36a,
843cbdf0-de18-402d-b021-01d864b097b2

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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
88792acc-7d87-4949-8369-3c459089a332,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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: 
2a285f58-9c50-403e-8221-1ead8361d1e2,
47c67078-5a7f-4427-9431-1bab6425cca5,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
94e1226f-d529-4585-8f88-ba099c24ddf0,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb,
002305ff-951e-46fd-98c7-cde9b221fd6f,
92d55579-f8bd-4d38-b97d-2c3b805105d3,
96170814-9d74-4f59-a908-f165312ec7a0,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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: 9ddd217a-4048-4802-8983-9324ab181e64

result, different first party: null

unsupported: false

passed: true

test failed: false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

read: () => sessionStorage.getItem("secret")

result, same first party: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa,
2e3531e6-80d7-404c-9fa0-7f5d66bed947,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
46c52812-ac93-4f36-b9a2-9ac351087915,
7e1a42d0-d90c-4adf-bace-00066fabf354,
ddac5d3a-603d-41cd-b9ae-7391f9304303

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_b732c02d-def9-4b33-929a-c76b16c9b345,
name_625a4d67-4292-4f87-8ea0-918f16d89cb3,
name_2424de9e-f493-4717-8424-72052e2d4a16,
name_54a72806-2901-4b14-989b-ecb256c7ab1a,
name_0a56a84e-07c9-460f-bc20-624f86de53e5

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_8d8faecd-0505-4e27-9a8a-61373f86e3c0,
name_d9589982-3c98-42d3-8409-24396a6b342c,
name_0a98c970-990f-4333-8b8f-7cc3070d77e1,
name_d24185c6-d67c-4c2a-a9a8-7c4080072888

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_4e4eee07-22a6-4d8b-8f35-927989baeaec,
name_b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
name_a69f17a8-a2a8-40d5-875f-dcf03f303c03,
name_8b71f061-2045-4416-b41a-16ec6cb2c36a,
name_843cbdf0-de18-402d-b021-01d864b097b2

result, different first party: 
name_4e4eee07-22a6-4d8b-8f35-927989baeaec,
name_b9189e50-ceff-46e9-99c4-9b3a6e9d0f10,
name_a69f17a8-a2a8-40d5-875f-dcf03f303c03,
name_8b71f061-2045-4416-b41a-16ec6cb2c36a,
name_843cbdf0-de18-402d-b021-01d864b097b2

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_4327f0fb-f9fe-4c98-b98c-7bef1261c757,
name_333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
name_88792acc-7d87-4949-8369-3c459089a332,
name_ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
name_e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

result, different first party: 
name_4327f0fb-f9fe-4c98-b98c-7bef1261c757,
name_333fb488-43f1-4ea6-8f6b-f7f29cfb1fee,
name_88792acc-7d87-4949-8369-3c459089a332,
name_ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe,
name_e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1

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_2a285f58-9c50-403e-8221-1ead8361d1e2,
name_47c67078-5a7f-4427-9431-1bab6425cca5,
name_b72f2e37-7e27-441c-bffd-83ef1c36ab3c,
name_94e1226f-d529-4585-8f88-ba099c24ddf0,
name_0feb5639-610e-49e0-97fd-6cb9ddd1b5cf

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_012e8d20-f032-4ce1-8349-bc8be6a070fb,
name_002305ff-951e-46fd-98c7-cde9b221fd6f,
name_92d55579-f8bd-4d38-b97d-2c3b805105d3,
name_96170814-9d74-4f59-a908-f165312ec7a0,
name_c2f2a353-33e4-4abc-9f56-9a02699d2e2d

result, different first party: 
name_012e8d20-f032-4ce1-8349-bc8be6a070fb,
name_002305ff-951e-46fd-98c7-cde9b221fd6f,
name_92d55579-f8bd-4d38-b97d-2c3b805105d3,
name_96170814-9d74-4f59-a908-f165312ec7a0,
name_c2f2a353-33e4-4abc-9f56-9a02699d2e2d

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_9ddd217a-4048-4802-8983-9324ab181e64

result, different first party: 

unsupported: false

passed: true

test failed: false
Passed
write: (secret) => window.name = "name_" + secret

read: () => window.name

result, same first party: 
name_0004ecc0-b4ee-466b-b82e-9f7470e8d9fa,
name_2e3531e6-80d7-404c-9fa0-7f5d66bed947,
name_7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6,
name_d991edc7-c2f5-4a18-b97e-93124c8ff9c5

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_a261f036-8227-4c44-ac4b-5d200cc71bdc,
name_0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
name_46c52812-ac93-4f36-b9a2-9ac351087915,
name_7e1a42d0-d90c-4adf-bace-00066fabf354,
name_ddac5d3a-603d-41cd-b9ae-7391f9304303

result, different first party: 
name_a261f036-8227-4c44-ac4b-5d200cc71bdc,
name_0b1443a8-add4-4e85-b9b8-1d438ddcd18d,
name_46c52812-ac93-4f36-b9a2-9ac351087915,
name_7e1a42d0-d90c-4adf-bace-00066fabf354,
name_ddac5d3a-603d-41cd-b9ae-7391f9304303

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
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
result: 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
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
Failed
upgraded: false
passed: false
Passed
upgraded: true, true, true, true
passed: 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
Failed
upgraded: false
passed: false
Passed
upgraded: true, true, true, true
passed: 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
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
result: loaded insecurely
Passed
passed: true, true, true, true
result: 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: blocked, blocked, blocked, blocked, blocked
Passed
passed: true
result: blocked
Passed
passed: true, true, true, true
result: upgraded, upgraded, upgraded, upgraded
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: encrypted
passed: true, false, true, true, false
Failed
SNI_status: plaintext
passed: false
Failed
SNI_status: plaintext
passed: false, false, false, false
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
Failed
header value: undefined
passed: false, false, false, false, false
Failed
header value: undefined
passed: false
Failed
header value: undefined
passed: 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
Failed
passed: false, false, false, false, false
Failed
passed: false
Failed
passed: 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
Passed
passed: true, true, true, true
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: 
92.205.185.52,
199.249.230.186,
192.42.116.173,
185.241.208.204
readDifferentFirstParty: 
92.205.185.52,
199.249.230.186,
192.42.116.173,
185.241.208.204
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
readSameFirstParty: Error: Unsupported
readDifferentFirstParty: Error: Unsupported
testFailed: 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
readSameFirstParty: 
2a03:e600:100::1,
2a02:ed06::222,
2a02:2970:1001::4c,
2a02:2970:1001::4c
readDifferentFirstParty: 
2001:67c:6ec:203:192:42:116:174,
2a03:94e0:ffff:185:181:61:0:115,
2a0b:f4c2:4::99,
2a03:94e0:ffff:185:243:218:0:202
passed: true, true, true, true
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
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
passed: 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
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: 1292,1290,1293,1289,1293
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 1288,1285,1287,1289
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
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: 860
desired value: undefined
passed: true
Passed
expression: undefined
desired expression: undefined
actual value: 900,900,900,900
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
Media query screen width
Width of the user's screen in pixels.
              
Passed
expression: undefined
desired expression: undefined
actual value: 1158,1163,1156,1156,1158
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 1157,1160,1161,1161
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
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: 1083
desired value: undefined
passed: true
Passed
expression: undefined
desired expression: undefined
actual value: 1400,1400,1400,1400
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
outerHeight
Height of the browser window in pixels, including browser chrome.
              
Passed
expression: outerHeight
desired expression: undefined
actual value: 1292,1290,1293,1289,1293
desired value: undefined
passed: true,true,true,true,true
Passed
expression: outerHeight
desired expression: undefined
actual value: 1288,1285,1287,1289
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
Failed
expression: outerHeight
desired expression: undefined
actual value: 1061,0,1061,1061,1061
desired value: undefined
passed: false,false,false,false,false
Passed
expression: outerHeight
desired expression: undefined
actual value: 860
desired value: undefined
passed: true
Passed
expression: outerHeight
desired expression: undefined
actual value: 900,900,900,900
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
screen.height
Height of the user's screen, in pixels.
              
Passed
expression: screen.height
desired expression: undefined
actual value: 1292,1290,1293,1289,1293
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screen.height
desired expression: undefined
actual value: 1288,1285,1287,1289
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
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: 860
desired value: undefined
passed: true
Passed
expression: screen.height
desired expression: undefined
actual value: 900,900,900,900
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
screen.width
Width of the user's screen, in pixels.
              
Passed
expression: screen.width
desired expression: undefined
actual value: 1158,1163,1156,1156,1158
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screen.width
desired expression: undefined
actual value: 1157,1160,1161,1161
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
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: 1083
desired value: undefined
passed: true
Passed
expression: screen.width
desired expression: undefined
actual value: 1400,1400,1400,1400
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
screenX
Position, in pixels, of the left edge of the browser window on screen.
              
Passed
expression: screenX
desired expression: undefined
actual value: 2,2,6,3,7
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 8,1,6,1
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
Failed
expression: screenX
desired expression: undefined
actual value: 320,0,320,320,320
desired value: undefined
passed: false,true,false,false,false
Passed
expression: screenX
desired expression: undefined
actual value: 0
desired value: undefined
passed: true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0,0
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
screenY
Position, in pixels, of the top edge of the browser window on screen.
              
Passed
expression: screenY
desired expression: undefined
actual value: 1,4,2,7,2
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 6,6,1,2
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
Failed
expression: screenY
desired expression: undefined
actual value: 202,0,202,202,202
desired value: undefined
passed: false,true,false,false,false
Passed
expression: screenY
desired expression: undefined
actual value: 0
desired value: undefined
passed: true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0,0
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
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.
              
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
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
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
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
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Failed
value: 8303910894658098
passed: false, false, false, false
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Failed
value: 8303910894658098
passed: false, false, false, false
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Failed
value: 8303910894658098
passed: false, false, false, false
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Failed
value: 8303910894658098
passed: false, false, false, false
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Failed
value: 8303910894658098
passed: false, false, false, false
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Failed
value: 8303910894658098
passed: false, false, false, false, false
Passed
passed: true
Passed
passed: true, true, true, true
Failed
value: 8303910894658098
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
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false, false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: 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
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false, false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false
Failed
url: https://dpm.demdex.net/ibs
passed: 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
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false, false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: 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
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
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: 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
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false, false, false
Failed
url: https://bat.bing.com/bat.js
passed: false
Failed
url: https://bat.bing.com/bat.js
passed: 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
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
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: 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
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
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: 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
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
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: 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
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
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: 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
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
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: 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
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false, false, false
Passed
url: https://google-analytics.com/urchin.js
passed: true
Failed
url: https://google-analytics.com/urchin.js
passed: 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
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
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: 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
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
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: 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
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
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: 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
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false, false, false
Passed
url: https://pixel.quantserve.com/pixel
passed: true
Failed
url: https://pixel.quantserve.com/pixel
passed: 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
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
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: 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
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
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: 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
Failed
url: https://t.co/i/adsct
passed: false, false, false, false, false
Failed
url: https://t.co/i/adsct
passed: false
Failed
url: https://t.co/i/adsct
passed: 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
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
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: 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
url: https://munchkin.marketo.net/munchkin.js
cookieFound: 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
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
url: https://dpm.demdex.net/ibs
cookieFound: 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
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
url: https://s.amazon-adsystem.com/dcm
cookieFound: 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
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
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: 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
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
url: https://bat.bing.com/bat.js
cookieFound: 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
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
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: 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
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
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: 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
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
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: 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
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
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: 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
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
url: https://www.google.com/pagead/1p-user-list/
cookieFound: 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
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
url: https://google-analytics.com/urchin.js
cookieFound: 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
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
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: 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
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
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: 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
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
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: 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
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
url: https://pixel.quantserve.com/pixel
cookieFound: 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
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
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: 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
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
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: 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
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
url: https://t.co/i/adsct
cookieFound: 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
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
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: 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
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
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

result, different session: h2

unsupported: true

passed: undefined

test failed: 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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345_1p,
625a4d67-4292-4f87-8ea0-918f16d89cb3_1p,
2424de9e-f493-4717-8424-72052e2d4a16_1p,
54a72806-2901-4b14-989b-ecb256c7ab1a_1p,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_1p,
d9589982-3c98-42d3-8409-24396a6b342c_1p,
0a98c970-990f-4333-8b8f-7cc3070d77e1_1p,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec_1p,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10_1p,
a69f17a8-a2a8-40d5-875f-dcf03f303c03_1p,
8b71f061-2045-4416-b41a-16ec6cb2c36a_1p,
843cbdf0-de18-402d-b021-01d864b097b2_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_1p,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_1p,
88792acc-7d87-4949-8369-3c459089a332_1p,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_1p,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_1p,
47c67078-5a7f-4427-9431-1bab6425cca5_1p,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_1p,
94e1226f-d529-4585-8f88-ba099c24ddf0_1p,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_1p

result, different session: 
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb_1p,
002305ff-951e-46fd-98c7-cde9b221fd6f_1p,
92d55579-f8bd-4d38-b97d-2c3b805105d3_1p,
96170814-9d74-4f59-a908-f165312ec7a0_1p,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d_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: undefined is not an object (evaluating 'cacheKeys[0].url')

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

unsupported: true

passed: undefined

test failed: 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.

result, different session: 
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

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc_1p,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d_1p,
46c52812-ac93-4f36-b9a2-9ac351087915_1p,
7e1a42d0-d90c-4adf-bace-00066fabf354_1p,
ddac5d3a-603d-41cd-b9ae-7391f9304303_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.
              
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

passed: undefined

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
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: null

result, different session: null

unsupported: true

passed: undefined

test failed: 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

passed: undefined

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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345_1p_js,
625a4d67-4292-4f87-8ea0-918f16d89cb3_1p_js,
2424de9e-f493-4717-8424-72052e2d4a16_1p_js,
54a72806-2901-4b14-989b-ecb256c7ab1a_1p_js,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_1p_js,
d9589982-3c98-42d3-8409-24396a6b342c_1p_js,
0a98c970-990f-4333-8b8f-7cc3070d77e1_1p_js,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec_1p_js,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10_1p_js,
a69f17a8-a2a8-40d5-875f-dcf03f303c03_1p_js,
8b71f061-2045-4416-b41a-16ec6cb2c36a_1p_js,
843cbdf0-de18-402d-b021-01d864b097b2_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_1p_js,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_1p_js,
88792acc-7d87-4949-8369-3c459089a332_1p_js,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_1p_js,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_1p_js,
47c67078-5a7f-4427-9431-1bab6425cca5_1p_js,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_1p_js,
94e1226f-d529-4585-8f88-ba099c24ddf0_1p_js,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb_1p_js,
002305ff-951e-46fd-98c7-cde9b221fd6f_1p_js,
92d55579-f8bd-4d38-b97d-2c3b805105d3_1p_js,
96170814-9d74-4f59-a908-f165312ec7a0_1p_js,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d_1p_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: null

result, different session: null

unsupported: true

passed: undefined

test failed: 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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa_1p_js,
2e3531e6-80d7-404c-9fa0-7f5d66bed947_1p_js,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6_1p_js,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5_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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc_1p_js,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d_1p_js,
46c52812-ac93-4f36-b9a2-9ac351087915_1p_js,
7e1a42d0-d90c-4adf-bace-00066fabf354_1p_js,
ddac5d3a-603d-41cd-b9ae-7391f9304303_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: 
b732c02d-def9-4b33-929a-c76b16c9b345_1p,
625a4d67-4292-4f87-8ea0-918f16d89cb3_1p,
2424de9e-f493-4717-8424-72052e2d4a16_1p,
54a72806-2901-4b14-989b-ecb256c7ab1a_1p,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_1p,
d9589982-3c98-42d3-8409-24396a6b342c_1p,
0a98c970-990f-4333-8b8f-7cc3070d77e1_1p,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec_1p,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10_1p,
a69f17a8-a2a8-40d5-875f-dcf03f303c03_1p,
8b71f061-2045-4416-b41a-16ec6cb2c36a_1p,
843cbdf0-de18-402d-b021-01d864b097b2_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_1p,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_1p,
88792acc-7d87-4949-8369-3c459089a332_1p,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_1p,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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
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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb_1p,
002305ff-951e-46fd-98c7-cde9b221fd6f_1p,
92d55579-f8bd-4d38-b97d-2c3b805105d3_1p,
96170814-9d74-4f59-a908-f165312ec7a0_1p,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d_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

result, different session: Error: Unsupported

unsupported: true

passed: undefined

test failed: 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

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true

passed: undefined

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc_1p,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d_1p,
46c52812-ac93-4f36-b9a2-9ac351087915_1p,
7e1a42d0-d90c-4adf-bace-00066fabf354_1p,
ddac5d3a-603d-41cd-b9ae-7391f9304303_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_38836670881616464,
fake_3248420473701048,
fake_6716219232336795,
fake_16956615474950243,
fake_4943901962263588

result, different session: 
fake_3560444243467795,
fake_6595068336937573,
fake_44552151635395765,
fake_9004140080584442,
fake_4653250982203736

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_029717311223603327,
fake_9658128564992265,
fake_7660787774239053,
fake_5829982106878993

result, different session: 
fake_4843917901389103,
fake_43500953175212853,
fake_3041340718062082,
fake_6983509207286682

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_23989624511237428,
fake_4832873087642706,
fake_8518869661671336,
fake_04007798022891684,
fake_6933576457457631

result, different session: 
fake_21039001977690708,
fake_18287892034691078,
fake_509005966498383,
fake_6346987803232356,
fake_3199951861862924

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_9703399561442303,
fake_2492467473070621,
fake_625791958258094,
fake_3189588849788183,
fake_25707114207055004

result, different session: 
fake_9834231617302474,
fake_7934288520329784,
fake_6696829910183921,
fake_20824655316689955,
fake_4818921525327664

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_025590712334684573,
fake_6266276870388185,
fake_4381304998894122,
fake_37448764044443617,
fake_6504316941125834

result, different session: 
fake_8502765624866586,
fake_3333117372263221,
fake_1022177357546099,
fake_25820073754736717,
fake_6519401471086899

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_2914095392291316,
fake_7890937594929763,
fake_00812572592647487,
fake_33602512186243105,
fake_5576860028333792

result, different session: 
fake_2482478551406535,
fake_8718128955766415,
fake_6756023450335367,
fake_8336253633059405,
fake_9437604204396306

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_797517102091349

result, different session: fake_6006290743439162

unsupported: false

passed: true

test failed: 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_7695946261478144,
fake_5626779965360451,
fake_6381698758903742,
fake_2542731276357264

result, different session: 
fake_3887204410951106,
fake_6233463468859199,
fake_6833338405390548,
fake_8038799400722685

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_06894890202120996,
fake_9533520566634923,
fake_6799311488683113,
fake_051920605122825814,
fake_35616404784797684

result, different session: 
fake_3504108581213832,
fake_14087770444142045,
fake_7758908527379582,
fake_7961290929565223,
fake_6057608832231836

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

result, different session: 2

unsupported: false

passed: true

test failed: 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: 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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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
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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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
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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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
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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345_1p,
625a4d67-4292-4f87-8ea0-918f16d89cb3_1p,
2424de9e-f493-4717-8424-72052e2d4a16_1p,
54a72806-2901-4b14-989b-ecb256c7ab1a_1p,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_1p,
d9589982-3c98-42d3-8409-24396a6b342c_1p,
0a98c970-990f-4333-8b8f-7cc3070d77e1_1p,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec_1p,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10_1p,
a69f17a8-a2a8-40d5-875f-dcf03f303c03_1p,
8b71f061-2045-4416-b41a-16ec6cb2c36a_1p,
843cbdf0-de18-402d-b021-01d864b097b2_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_1p,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_1p,
88792acc-7d87-4949-8369-3c459089a332_1p,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_1p,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_1p,
47c67078-5a7f-4427-9431-1bab6425cca5_1p,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_1p,
94e1226f-d529-4585-8f88-ba099c24ddf0_1p,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb_1p,
002305ff-951e-46fd-98c7-cde9b221fd6f_1p,
92d55579-f8bd-4d38-b97d-2c3b805105d3_1p,
96170814-9d74-4f59-a908-f165312ec7a0_1p,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d_1p

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: undefined

result, different session: undefined

unsupported: true

passed: undefined

test failed: 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: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa_1p,
2e3531e6-80d7-404c-9fa0-7f5d66bed947_1p,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6_1p,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5_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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc_1p,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d_1p,
46c52812-ac93-4f36-b9a2-9ac351087915_1p,
7e1a42d0-d90c-4adf-bace-00066fabf354_1p,
ddac5d3a-603d-41cd-b9ae-7391f9304303_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: 
b732c02d-def9-4b33-929a-c76b16c9b345_1p,
625a4d67-4292-4f87-8ea0-918f16d89cb3_1p,
2424de9e-f493-4717-8424-72052e2d4a16_1p,
54a72806-2901-4b14-989b-ecb256c7ab1a_1p,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_1p,
d9589982-3c98-42d3-8409-24396a6b342c_1p,
0a98c970-990f-4333-8b8f-7cc3070d77e1_1p,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec_1p,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10_1p,
a69f17a8-a2a8-40d5-875f-dcf03f303c03_1p,
8b71f061-2045-4416-b41a-16ec6cb2c36a_1p,
843cbdf0-de18-402d-b021-01d864b097b2_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_1p,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_1p,
88792acc-7d87-4949-8369-3c459089a332_1p,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_1p,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_1p,
47c67078-5a7f-4427-9431-1bab6425cca5_1p,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_1p,
94e1226f-d529-4585-8f88-ba099c24ddf0_1p,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb_1p,
002305ff-951e-46fd-98c7-cde9b221fd6f_1p,
92d55579-f8bd-4d38-b97d-2c3b805105d3_1p,
96170814-9d74-4f59-a908-f165312ec7a0_1p,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d_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: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: null

result, different session: null

unsupported: true

passed: undefined

test failed: false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
0004ecc0-b4ee-466b-b82e-9f7470e8d9fa_1p,
2e3531e6-80d7-404c-9fa0-7f5d66bed947_1p,
7f8ec0d0-78f7-43c5-a86a-e538fa4e5ed6_1p,
d991edc7-c2f5-4a18-b97e-93124c8ff9c5_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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc_1p,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d_1p,
46c52812-ac93-4f36-b9a2-9ac351087915_1p,
7e1a42d0-d90c-4adf-bace-00066fabf354_1p,
ddac5d3a-603d-41cd-b9ae-7391f9304303_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
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

result, different session: Error: No requests received

unsupported: true

passed: undefined

test failed: 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

result, different session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true

passed: undefined

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
script cache
Caching of scripts 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

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

result, same session: 2

result, different session: 3

unsupported: false

passed: true

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

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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
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: Web SQL is deprecated

result, different session: Error: Web SQL is deprecated

unsupported: true

passed: undefined

test failed: 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
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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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
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
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

result, different session: h2

unsupported: true

passed: undefined

test failed: 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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345_3p,
625a4d67-4292-4f87-8ea0-918f16d89cb3_3p,
2424de9e-f493-4717-8424-72052e2d4a16_3p,
54a72806-2901-4b14-989b-ecb256c7ab1a_3p,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_3p,
d9589982-3c98-42d3-8409-24396a6b342c_3p,
0a98c970-990f-4333-8b8f-7cc3070d77e1_3p,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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')

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec_3p,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10_3p,
a69f17a8-a2a8-40d5-875f-dcf03f303c03_3p,
8b71f061-2045-4416-b41a-16ec6cb2c36a_3p,
843cbdf0-de18-402d-b021-01d864b097b2_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_3p,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_3p,
88792acc-7d87-4949-8369-3c459089a332_3p,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_3p,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_3p,
47c67078-5a7f-4427-9431-1bab6425cca5_3p,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_3p,
94e1226f-d529-4585-8f88-ba099c24ddf0_3p,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_3p

result, different session: 
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined

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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb_3p,
002305ff-951e-46fd-98c7-cde9b221fd6f_3p,
92d55579-f8bd-4d38-b97d-2c3b805105d3_3p,
96170814-9d74-4f59-a908-f165312ec7a0_3p,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d_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: undefined is not an object (evaluating 'cacheKeys[0].url')

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

unsupported: true

passed: undefined

test failed: 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.

result, different session: 
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

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc_3p,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d_3p,
46c52812-ac93-4f36-b9a2-9ac351087915_3p,
7e1a42d0-d90c-4adf-bace-00066fabf354_3p,
ddac5d3a-603d-41cd-b9ae-7391f9304303_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: 
b732c02d-def9-4b33-929a-c76b16c9b345_3p_http,
625a4d67-4292-4f87-8ea0-918f16d89cb3_3p_http,
2424de9e-f493-4717-8424-72052e2d4a16_3p_http,
54a72806-2901-4b14-989b-ecb256c7ab1a_3p_http,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_3p_http,
d9589982-3c98-42d3-8409-24396a6b342c_3p_http,
0a98c970-990f-4333-8b8f-7cc3070d77e1_3p_http,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_3p_http,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_3p_http,
88792acc-7d87-4949-8369-3c459089a332_3p_http,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_3p_http,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_3p_http,
47c67078-5a7f-4427-9431-1bab6425cca5_3p_http,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_3p_http,
94e1226f-d529-4585-8f88-ba099c24ddf0_3p_http,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_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: null

result, different session: null

unsupported: true

passed: undefined

test failed: 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

passed: undefined

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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345_3p_js,
625a4d67-4292-4f87-8ea0-918f16d89cb3_3p_js,
2424de9e-f493-4717-8424-72052e2d4a16_3p_js,
54a72806-2901-4b14-989b-ecb256c7ab1a_3p_js,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_3p_js,
d9589982-3c98-42d3-8409-24396a6b342c_3p_js,
0a98c970-990f-4333-8b8f-7cc3070d77e1_3p_js,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_3p_js,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_3p_js,
88792acc-7d87-4949-8369-3c459089a332_3p_js,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_3p_js,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_3p_js,
47c67078-5a7f-4427-9431-1bab6425cca5_3p_js,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_3p_js,
94e1226f-d529-4585-8f88-ba099c24ddf0_3p_js,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_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: null

result, different session: null

unsupported: true

passed: undefined

test failed: 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

passed: undefined

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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345_3p,
625a4d67-4292-4f87-8ea0-918f16d89cb3_3p,
2424de9e-f493-4717-8424-72052e2d4a16_3p,
54a72806-2901-4b14-989b-ecb256c7ab1a_3p,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_3p,
d9589982-3c98-42d3-8409-24396a6b342c_3p,
0a98c970-990f-4333-8b8f-7cc3070d77e1_3p,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_3p,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_3p,
88792acc-7d87-4949-8369-3c459089a332_3p,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_3p,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: , , , , 

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

result, different session: Error: Unsupported

unsupported: true

passed: undefined

test failed: 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

result, different session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

unsupported: true, true, true, true

passed: undefined

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
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_8371294926875292,
fake_7079629626463075,
fake_40102202108057927,
fake_2953202426972825,
fake_046793480948292165

result, different session: 
fake_9738774621555335,
fake_12604572680555348,
fake_5604934855668473,
fake_14778223850525185,
fake_29167833756322104

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_1469146054332846,
fake_1616338235726542,
fake_4151223466437579,
fake_014472898005971846

result, different session: 
fake_6370657091339613,
fake_907381559760438,
fake_045997935169183046,
fake_22333856656016038

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_4173569340892087,
fake_5865321035671156,
fake_05788256371636691,
fake_4054798050576045,
fake_8082426556129692

result, different session: 
fake_23923482202843593,
fake_11766896648259206,
fake_2735542247742877,
fake_6425178391652704,
fake_8955404541443241

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_04613617848341689,
fake_18311433922061449,
fake_9570800510315918,
fake_31283401910900843,
fake_9305594021183405

result, different session: 
fake_5050710588215475,
fake_06024324962365357,
fake_9157071911855583,
fake_08333987974857693,
fake_6549436859035107

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_8385672533255666,
fake_02488046549433287,
fake_2923182979061556,
fake_7628645497126005,
fake_16935882372733202

result, different session: 
fake_9324192339625583,
fake_3938017636244415,
fake_4423917717865542,
fake_5896403412184059,
fake_912072662823487

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_5194372201230031,
fake_7314304131891258,
fake_8467951172161379,
fake_057177071458369255,
fake_16882929622165244

result, different session: 
fake_6609185317672934,
fake_35306332837773735,
fake_5191508760611792,
fake_783426790812058,
fake_5763840539619218

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_4107630792435748

result, different session: fake_5556999646648297

unsupported: false

passed: true

test failed: 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_5943099926499185,
fake_7729752193108548,
fake_6640045230834803,
fake_8398186170107103

result, different session: 
fake_6324159323881204,
fake_8680760987200868,
fake_43255894146567475,
fake_6656526765269108

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_6644022782420693,
fake_795625674872956,
fake_8098102264550595,
fake_48403059352097566,
fake_7771577998940904

result, different session: 
fake_20339143647401592,
fake_46406701606976575,
fake_12124655695743858,
fake_5322596943769824,
fake_553578631192625

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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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: 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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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
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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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
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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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
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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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
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: 
b732c02d-def9-4b33-929a-c76b16c9b345_3p,
625a4d67-4292-4f87-8ea0-918f16d89cb3_3p,
2424de9e-f493-4717-8424-72052e2d4a16_3p,
54a72806-2901-4b14-989b-ecb256c7ab1a_3p,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_3p,
d9589982-3c98-42d3-8409-24396a6b342c_3p,
0a98c970-990f-4333-8b8f-7cc3070d77e1_3p,
d24185c6-d67c-4c2a-a9a8-7c4080072888_3p

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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec_3p,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10_3p,
a69f17a8-a2a8-40d5-875f-dcf03f303c03_3p,
8b71f061-2045-4416-b41a-16ec6cb2c36a_3p,
843cbdf0-de18-402d-b021-01d864b097b2_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_3p,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_3p,
88792acc-7d87-4949-8369-3c459089a332_3p,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_3p,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_3p,
47c67078-5a7f-4427-9431-1bab6425cca5_3p,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_3p,
94e1226f-d529-4585-8f88-ba099c24ddf0_3p,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb_3p,
002305ff-951e-46fd-98c7-cde9b221fd6f_3p,
92d55579-f8bd-4d38-b97d-2c3b805105d3_3p,
96170814-9d74-4f59-a908-f165312ec7a0_3p,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d_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: undefined

result, different session: undefined

unsupported: true

passed: undefined

test failed: 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.

result, different session: 
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

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: 
a261f036-8227-4c44-ac4b-5d200cc71bdc_3p,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d_3p,
46c52812-ac93-4f36-b9a2-9ac351087915_3p,
7e1a42d0-d90c-4adf-bace-00066fabf354_3p,
ddac5d3a-603d-41cd-b9ae-7391f9304303_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: 
b732c02d-def9-4b33-929a-c76b16c9b345_3p,
625a4d67-4292-4f87-8ea0-918f16d89cb3_3p,
2424de9e-f493-4717-8424-72052e2d4a16_3p,
54a72806-2901-4b14-989b-ecb256c7ab1a_3p,
0a56a84e-07c9-460f-bc20-624f86de53e5_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: 
8d8faecd-0505-4e27-9a8a-61373f86e3c0_3p,
d9589982-3c98-42d3-8409-24396a6b342c_3p,
0a98c970-990f-4333-8b8f-7cc3070d77e1_3p,
d24185c6-d67c-4c2a-a9a8-7c4080072888_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: 
4e4eee07-22a6-4d8b-8f35-927989baeaec_3p,
b9189e50-ceff-46e9-99c4-9b3a6e9d0f10_3p,
a69f17a8-a2a8-40d5-875f-dcf03f303c03_3p,
8b71f061-2045-4416-b41a-16ec6cb2c36a_3p,
843cbdf0-de18-402d-b021-01d864b097b2_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: 
4327f0fb-f9fe-4c98-b98c-7bef1261c757_3p,
333fb488-43f1-4ea6-8f6b-f7f29cfb1fee_3p,
88792acc-7d87-4949-8369-3c459089a332_3p,
ed40eb6d-1f32-4b61-9bd4-10b3f5b37bbe_3p,
e5604a20-7b9d-4d9d-8d1a-c553fb1ea9f1_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: 
2a285f58-9c50-403e-8221-1ead8361d1e2_3p,
47c67078-5a7f-4427-9431-1bab6425cca5_3p,
b72f2e37-7e27-441c-bffd-83ef1c36ab3c_3p,
94e1226f-d529-4585-8f88-ba099c24ddf0_3p,
0feb5639-610e-49e0-97fd-6cb9ddd1b5cf_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: 
012e8d20-f032-4ce1-8349-bc8be6a070fb_3p,
002305ff-951e-46fd-98c7-cde9b221fd6f_3p,
92d55579-f8bd-4d38-b97d-2c3b805105d3_3p,
96170814-9d74-4f59-a908-f165312ec7a0_3p,
c2f2a353-33e4-4abc-9f56-9a02699d2e2d_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: null

result, different session: null

unsupported: true

passed: undefined

test failed: 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.

result, different session: 
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

passed: undefined

test failed: false, false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)

read: () => localStorage.getItem("secret")

result, same session: 
a261f036-8227-4c44-ac4b-5d200cc71bdc_3p,
0b1443a8-add4-4e85-b9b8-1d438ddcd18d_3p,
46c52812-ac93-4f36-b9a2-9ac351087915_3p,
7e1a42d0-d90c-4adf-bace-00066fabf354_3p,
ddac5d3a-603d-41cd-b9ae-7391f9304303_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
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

result, different session: Error: No requests received

unsupported: true

passed: undefined

test failed: 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

result, different session: 
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received

unsupported: true, true, true, true

passed: undefined

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
script cache
Caching of scripts 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

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

result, same session: 2

result, different session: 3

unsupported: false

passed: true

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

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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 script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })

read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", 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
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: Web SQL is deprecated

result, different session: Error: Web SQL is deprecated

unsupported: true

passed: undefined

test failed: 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
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: 2

result, different session: 3

unsupported: false

passed: true

test failed: 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
DNS privacy testsWhich browsers keep their DNS queries encrypted?
The Domain Name System (DNS) is the method by which web browsers look up the IP address for each website you visit. In a DNS query, a web browser will ask a DNS resolver (somewhere on the internet) for the IP address corresponding to a domain name (such as nytimes.com) for a website you want to visit. Traditionally, most web browsers have sent their DNS queries unencrypted, which means your ISP or anyone else on the network between your computer and the DNS resolver can eavesdrop on the websites you visit. In recent years, web browsers and operating systems have begun to introduce encrypted DNS, including the DNS over HTTPS (DoH) protocol, to encrypt the DNS request from your browser and the response from the resolver to keep your browsing history from leaking. These tests check whether a browser is still protecting its DNS requests by sending them encrypted.
        
Location: Brazil
  Checks whether the browser decides to use
  encrypted DNS if the computer is located in Brazil.
              
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false
leak detected: true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Location: China
  Checks whether the browser decides to use
  encrypted DNS if the computer is located in China.
              
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false
leak detected: true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Location: Germany
  Checks whether the browser decides to use
  encrypted DNS if the computer is located in Germany.
              
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false
leak detected: true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Location: India
  Checks whether the browser decides to use
  encrypted DNS if the computer is located in India.
              
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false
leak detected: true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Location: Nigeria
  Checks whether the browser decides to use
  encrypted DNS if the computer is located in Nigeria.
              
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false
leak detected: true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Location: Russia
  Checks whether the browser decides to use
  encrypted DNS if the computer is located in Russia.
              
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false
leak detected: true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Location: United States
  Checks whether the browser decides to use
  encrypted DNS if the computer is located in United States.
              
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false
leak detected: true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
OS DNS: Cloudflare
  Checks whether the browser decides to use
  encrypted DNS if the operating system's default DNS provider is Cloudflare.
              
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true
leak detected: false
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
OS DNS: Comodo
  Checks whether the browser decides to use
  encrypted DNS if the operating system's default DNS provider is Comodo.
              
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false
leak detected: true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
OS DNS: Google
  Checks whether the browser decides to use
  encrypted DNS if the operating system's default DNS provider is Google.
              
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true
leak detected: false
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
OS DNS: Quad9
  Checks whether the browser decides to use
  encrypted DNS if the operating system's default DNS provider is Quad9.
              
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true, true, true, true, true
leak detected: false, false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true
leak detected: false
Passed
passed: true, true, true, true
leak detected: false, false, false, false
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true