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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,
Error: Unsupported

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

unsupported: true, true, true, true, true

passed: undefined

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
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

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

unsupported: false, false, false, false

passed: true, true, true, true

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
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: h3

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

result, different first party: h2, h2

unsupported: true, true

passed: undefined

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same first party: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

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
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: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

result, different first party: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

result, different first party: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
dc358174-9143-4559-8f1d-9c82f8aa667a,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
6bfe177c-474d-4f3c-8f4d-427de07e6de7

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
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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6,
7e6654c2-f192-439d-9be7-69a4adc7f88f,
8e59b87b-2264-4cca-993a-b137beaef0f4,
78e4be88-4707-457a-b232-e08e7fb191f7,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same first party: 
fafedf2e-7fa1-43d0-80c7-45ba53483656,
354678be-2d77-43e5-acd3-527d66e47575,
89417684-5d59-4c2e-8b5c-9f4525a087c4,
dc38efa5-2fb1-4aed-ad8b-64362865f462,
daa6e92d-9722-4353-bd91-2aba17a2f098

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: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

result, different first party: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e

result, different first party: Error: Load failed

unsupported: false

passed: true

test failed: 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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0,
2b2c596a-47f4-4a38-b4d7-f408027254b8

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

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

result, different first party: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

result, different first party: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

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: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
dc358174-9143-4559-8f1d-9c82f8aa667a,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
6bfe177c-474d-4f3c-8f4d-427de07e6de7

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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6,
7e6654c2-f192-439d-9be7-69a4adc7f88f,
8e59b87b-2264-4cca-993a-b137beaef0f4,
78e4be88-4707-457a-b232-e08e7fb191f7,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656,
354678be-2d77-43e5-acd3-527d66e47575,
89417684-5d59-4c2e-8b5c-9f4525a087c4,
dc38efa5-2fb1-4aed-ad8b-64362865f462,
daa6e92d-9722-4353-bd91-2aba17a2f098

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same first party: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e

result, different first party: Error: no BroadcastChannel message

unsupported: false

passed: true

test failed: 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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0,
2b2c596a-47f4-4a38-b4d7-f408027254b8

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

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same first party: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same first party: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
dc358174-9143-4559-8f1d-9c82f8aa667a,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
6bfe177c-474d-4f3c-8f4d-427de07e6de7

result, different first party: 
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined

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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6,
7e6654c2-f192-439d-9be7-69a4adc7f88f,
8e59b87b-2264-4cca-993a-b137beaef0f4,
78e4be88-4707-457a-b232-e08e7fb191f7,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

result, different first party: 
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same first party: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e

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

unsupported: false

passed: true

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

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

unsupported: true, true

passed: undefined

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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: 
efe81322-bc41-43c1-9f2a-efc60712933b_http,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_http,
b0e98059-2520-4716-bcc2-f2efe3980689_http,
f76831a6-090e-4a03-8c56-e81ef1fd258f_http,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_http,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_http,
fa551d24-37e5-4566-ab64-de3420e474f5_http,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_http,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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: 
2670a08e-e954-4bbe-b23f-224b90ca1075_http,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_http,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_http,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_http,
54871a50-ba91-4267-8b5e-5200f05a2e8e_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: 
248c312b-c058-4c05-be9b-239817a7d9fa_http,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_http,
a553c9a8-1901-4af8-8805-a66e0cb047ae_http,
4d81c129-5192-47a7-8e96-56f15a9a252d_http,
63487cfc-7648-4b4b-8b7b-df0b502173c1_http

result, different first party: 
248c312b-c058-4c05-be9b-239817a7d9fa_http,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_http,
a553c9a8-1901-4af8-8805-a66e0cb047ae_http,
4d81c129-5192-47a7-8e96-56f15a9a252d_http,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_http,
dc358174-9143-4559-8f1d-9c82f8aa667a_http,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_http,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_http,
7e6654c2-f192-439d-9be7-69a4adc7f88f_http,
8e59b87b-2264-4cca-993a-b137beaef0f4_http,
78e4be88-4707-457a-b232-e08e7fb191f7_http,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656_http,
354678be-2d77-43e5-acd3-527d66e47575_http,
89417684-5d59-4c2e-8b5c-9f4525a087c4_http,
dc38efa5-2fb1-4aed-ad8b-64362865f462_http,
daa6e92d-9722-4353-bd91-2aba17a2f098_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: 
551baa61-066c-4133-8848-693e3f38e45f_http,
46ffd76a-1163-4fce-973f-a95ac12666e2_http,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_http,
4e123750-fbfb-4991-930d-efda2e2071ae_http,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_http

result, different first party: null

unsupported: false

passed: true

test failed: 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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0_http,
2b2c596a-47f4-4a38-b4d7-f408027254b8_http

result, different first party: , 

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694_http,
45bda111-36f5-4cba-af47-17f53bc255ef_http,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_http,
d88a1655-b840-4fb7-88ac-68450644649a_http,
01fea522-8483-4538-8719-3849d0c0818c_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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_http,
660baa93-30ce-41ff-bba6-879edeb0311b_http,
5acb01d8-0c36-4846-9204-26566e4e0798_http,
b78097b8-cd9a-4416-942d-8ca66805db24_http,
7f09e611-54ee-4b27-94da-b0894408819a_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: 
efe81322-bc41-43c1-9f2a-efc60712933b_js,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_js,
b0e98059-2520-4716-bcc2-f2efe3980689_js,
f76831a6-090e-4a03-8c56-e81ef1fd258f_js,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_js,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_js,
fa551d24-37e5-4566-ab64-de3420e474f5_js,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_js,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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: 
2670a08e-e954-4bbe-b23f-224b90ca1075_js,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_js,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_js,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_js,
54871a50-ba91-4267-8b5e-5200f05a2e8e_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: 
248c312b-c058-4c05-be9b-239817a7d9fa_js,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_js,
a553c9a8-1901-4af8-8805-a66e0cb047ae_js,
4d81c129-5192-47a7-8e96-56f15a9a252d_js,
63487cfc-7648-4b4b-8b7b-df0b502173c1_js

result, different first party: 
248c312b-c058-4c05-be9b-239817a7d9fa_js,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_js,
a553c9a8-1901-4af8-8805-a66e0cb047ae_js,
4d81c129-5192-47a7-8e96-56f15a9a252d_js,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_js,
dc358174-9143-4559-8f1d-9c82f8aa667a_js,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_js,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_js,
7e6654c2-f192-439d-9be7-69a4adc7f88f_js,
8e59b87b-2264-4cca-993a-b137beaef0f4_js,
78e4be88-4707-457a-b232-e08e7fb191f7_js,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656_js,
354678be-2d77-43e5-acd3-527d66e47575_js,
89417684-5d59-4c2e-8b5c-9f4525a087c4_js,
dc38efa5-2fb1-4aed-ad8b-64362865f462_js,
daa6e92d-9722-4353-bd91-2aba17a2f098_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: 
551baa61-066c-4133-8848-693e3f38e45f_js,
46ffd76a-1163-4fce-973f-a95ac12666e2_js,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_js,
4e123750-fbfb-4991-930d-efda2e2071ae_js,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_js

result, different first party: null

unsupported: false

passed: true

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 first party: 
a5df7538-e481-4697-83c2-d0c429d5a9c0_js,
2b2c596a-47f4-4a38-b4d7-f408027254b8_js

result, different first party: , 

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694_js,
45bda111-36f5-4cba-af47-17f53bc255ef_js,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_js,
d88a1655-b840-4fb7-88ac-68450644649a_js,
01fea522-8483-4538-8719-3849d0c0818c_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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_js,
660baa93-30ce-41ff-bba6-879edeb0311b_js,
5acb01d8-0c36-4846-9204-26566e4e0798_js,
b78097b8-cd9a-4416-942d-8ca66805db24_js,
7f09e611-54ee-4b27-94da-b0894408819a_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: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

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: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

result, different first party: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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

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

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

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

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

unsupported: true, true, true, true, true

passed: undefined

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

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

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

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

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same first party: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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

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

unsupported: true, true

passed: undefined

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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_2728284715261149,
fake_46414653665076133,
fake_3481768429826555,
fake_129698966696411,
fake_5061089092202669

result, different first party: 
fake_10551266422155647,
fake_477851604867813,
fake_8920831712454627,
fake_9680880867332384,
fake_600277461160819

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_03546102598231937,
fake_8622512416876886,
fake_24724056651361082,
fake_040670157903063275,
fake_223670948889789

result, different first party: 
fake_47642791373108606,
fake_47972044050782237,
fake_07425094461481674,
fake_8456181681951505,
fake_0018785458419712242

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_42672801637764946,
fake_5213753043277387,
fake_8724625608687466,
fake_32522207151560734,
fake_796933745172814

result, different first party: 
fake_8521914625561247,
fake_6046318550744698,
fake_23986719599330364,
fake_9804037732051925,
fake_8811580032201385

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_6482854507262883,
fake_6643256805235553,
fake_0002110060368221145,
fake_4579187700109575,
fake_966566674917483

result, different first party: 
fake_13068986404320215,
fake_168011599273177,
fake_49400602426707496,
fake_6149478636412318,
fake_8680977652014308

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_16078752591718537,
fake_3475295568493266,
fake_4405540496911531,
fake_4345283952270629

result, different first party: 
fake_5787633379649553,
fake_678136005096281,
fake_7769936292998509,
fake_06486665061774821

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_8746075644632916,
fake_7649961557411913,
fake_3678873914568872,
fake_450394689284092,
fake_23917368980149445

result, different first party: 
fake_8390424332757647,
fake_36171132431552566,
fake_5431763547304695,
fake_026018879756188218,
fake_6574167058856493

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_8057693314865322,
fake_018654373402335667,
fake_8745093796831305,
fake_7073488437896995,
fake_4989048731471859

result, different first party: 
fake_4739965865887026,
fake_033275641900174735,
fake_9198884427932537,
fake_3111069184252966,
fake_5943402423627726

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_4728117629188926,
fake_8442464951685333,
fake_796325160820013,
fake_10612803531225756,
fake_24512213542685268

result, different first party: 
fake_9016102490135847,
fake_8519962165937391,
fake_29755845672984216,
fake_01174842956792821,
fake_7870816323689753

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_9461593159142891

result, different first party: fake_5120400930868572

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_9694283495192793,
fake_08441252746819394

result, different first party: 
fake_03182991150331205,
fake_44691302781002307

unsupported: false, false

passed: true, true

test failed: 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_8754883340973643,
fake_06757098185138144,
fake_3380747581204948,
fake_7200751753647052,
fake_4501270947889393

result, different first party: 
fake_1473185852397667,
fake_28789801403889137,
fake_013652779536031723,
fake_3775151064516411,
fake_5310287363582209

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_7371759553090023,
fake_5965427485601804,
fake_5412808860413341,
fake_27523186245447717,
fake_22129814269306003

result, different first party: 
fake_34509177379263356,
fake_7687224547145255,
fake_9240970420974761,
fake_955146960967445,
fake_8004017711562585

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, 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

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

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

result, different first party: 2, 2

unsupported: false, false

passed: true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

result, different first party: 2

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

result, different first party: 2, 2

unsupported: false, false

passed: true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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: 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

result, different first party: 2, 2

unsupported: false, false

passed: true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same first party: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

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: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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

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

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

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

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

unsupported: true, true, true, true, true

passed: undefined

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

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

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

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

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same first party: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same first party: 

result, different first party: Error: Unsupported

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

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

unsupported: true, true

passed: undefined

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

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: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
dc358174-9143-4559-8f1d-9c82f8aa667a,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
6bfe177c-474d-4f3c-8f4d-427de07e6de7

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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6,
7e6654c2-f192-439d-9be7-69a4adc7f88f,
8e59b87b-2264-4cca-993a-b137beaef0f4,
78e4be88-4707-457a-b232-e08e7fb191f7,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656,
354678be-2d77-43e5-acd3-527d66e47575,
89417684-5d59-4c2e-8b5c-9f4525a087c4,
dc38efa5-2fb1-4aed-ad8b-64362865f462,
daa6e92d-9722-4353-bd91-2aba17a2f098

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: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e

result, different first party: 

unsupported: false

passed: true

test failed: 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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0,
2b2c596a-47f4-4a38-b4d7-f408027254b8

result, different first party: , 

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

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: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
dc358174-9143-4559-8f1d-9c82f8aa667a,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
6bfe177c-474d-4f3c-8f4d-427de07e6de7

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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6,
7e6654c2-f192-439d-9be7-69a4adc7f88f,
8e59b87b-2264-4cca-993a-b137beaef0f4,
78e4be88-4707-457a-b232-e08e7fb191f7,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656,
354678be-2d77-43e5-acd3-527d66e47575,
89417684-5d59-4c2e-8b5c-9f4525a087c4,
dc38efa5-2fb1-4aed-ad8b-64362865f462,
daa6e92d-9722-4353-bd91-2aba17a2f098

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: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e

result, different first party: 

unsupported: false

passed: true

test failed: 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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0,
2b2c596a-47f4-4a38-b4d7-f408027254b8

result, different first party: , 

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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: 
4234cd7875c9c3757bd1efd620ee7e13,
eff18756ee999bfeb7d58b43257bc90b,
4f66bf8be2c1765a9b75830bb498fc4a,
ff963165dc64f62d57c0b0eebde003f2,
2d0ab02e0b2d9d69f49a20ddacb416ca

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, true

passed: undefined

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

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

result, same first party: 
c663fc36845d66a1c3554eeb54f5bcad,
f0ce8cf65c37e372d3aa6a8799f705ae,
0a3d2c89d357e1abe7449cf76f9a3201,
36d1559ddbb4ad8250d62ab7f7508d5b,
690f3b86cd24df87f6a64d2ec5f7e213

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: 
684f0354ee1c22bb4eccfc7a49b4316a,
37fbf9327bc9e8d9bc90830f9815eaf2,
081878d39fa32f3b5237c213af2d85d7,
cffbfb58741a7654395d7b4f560e08e5,
3bdc609ab4a6d9530fc7fd9bed40a626

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: 
c35ed8424c4ceaa7194f09eae3b63f9d,
254a2e36b5258aae347651e83b8af7f7,
a7d42b368bcd072149a10974051256ec,
96569e5727ca0a3c2b36370719b085f1

result, different first party: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

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: 
1d4a6fe7ca58c9fb9a6f2590b6661a69,
b7e669e0d8f9278faca71993fdbc8e1f,
7ebdc6ff3ae8241ca3a233970a0f0d9d,
1f4977a0d9cb0ff2beb28576e13c3a7d,
2f35782f931739ca612dedc8cff5735d

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: 
883c8be9fe6ab052b633a54b9dbb1c8f,
755d2c5f3caaa46e99f78855bd09e8e8,
b82931ee47f0923a951f78e5a570d9eb,
4a043ccc95ca8a663e677faeae0a9394,
d458fdf6042d47756d5e04adc5fca143

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: 
80418550da246aea104f85a46d92d196,
5301b14f7425a3279976e3ed2c6c171b,
cbf92d91edf592dfb5a97334c6dd368e,
e54a85fadab065b45f65902234745f8f,
9bac83dc4c732a9915dc2c933763d010

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: 687d10391723ed7ce4e3250a653f238c

result, different first party: edc370eb813ced55251d95eb4e2fad87

unsupported: false

passed: true

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

passed: undefined

test failed: 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: 
2a30061915c4826e229e8a3c53f27d19,
4e10150cd7178412aa1c07a7f8ee35d4,
c1ff322fe0130d722c13a9ba76da0c5f,
ea27bc868c68e056b50ea3ec22319dd7,
6a42aa9cdf5a901d7baf1bdcfcf1bf57

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: 
5793e585f11c8aa2850c0f9a546ea7ca,
c5840310e672c7f3676b22a85923b564,
0bb59f8a6e6a8c0c826a794c920ee9c0,
8d381e4ced4fc32d1876adef92ed5ffe,
012db20ef86777dc0473e8889d7719c7

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,
HTTPS used by default; no HSTS cache issue expected

unsupported: , , , , 

passed: true, true, true, true, true

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

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

read: read HSTS flag

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

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

unsupported: false, false, false, false

passed: true, true, true, true

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

read: null

result, same first party: , , , , 

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

unsupported: , , , , 

passed: true, true, true, true, true

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

read: null

result, same first party: , , , , 

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

unsupported: , , , , 

passed: true, true, true, true, true

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

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

read: read HSTS flag

result, same first party: not tested

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

unsupported: , 

passed: true, true

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

read: null

result, same first party: , , , , 

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

unsupported: , , , , 

passed: true, true, true, true, true

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

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

read: read HSTS flag

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

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

unsupported: false, false, false, false

passed: true, true, true, true

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

read: null

result, same first party: , , , , 

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

unsupported: , , , , 

passed: true, true, true, true, true

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

read: null

result, same first party: , , , , 

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

unsupported: , , , , 

passed: true, true, true, true, true

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

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

read: read HSTS flag

result, same first party: not tested

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

unsupported: , 

passed: true, true

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

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

read: read HSTS flag

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

result, different first party: 2

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

result, different first party: 2, 2

unsupported: false, false

passed: true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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: 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

result, different first party: 2, 2

unsupported: false, false

passed: true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
indexedDB
The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
              
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

result, different first party: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

result, different first party: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
dc358174-9143-4559-8f1d-9c82f8aa667a,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
6bfe177c-474d-4f3c-8f4d-427de07e6de7

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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6,
7e6654c2-f192-439d-9be7-69a4adc7f88f,
8e59b87b-2264-4cca-993a-b137beaef0f4,
78e4be88-4707-457a-b232-e08e7fb191f7,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656,
354678be-2d77-43e5-acd3-527d66e47575,
89417684-5d59-4c2e-8b5c-9f4525a087c4,
dc38efa5-2fb1-4aed-ad8b-64362865f462,
daa6e92d-9722-4353-bd91-2aba17a2f098

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same first party: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e

result, different first party: undefined

unsupported: false

passed: true

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 first party: 
a5df7538-e481-4697-83c2-d0c429d5a9c0,
2b2c596a-47f4-4a38-b4d7-f408027254b8

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

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

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: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
dc358174-9143-4559-8f1d-9c82f8aa667a,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
6bfe177c-474d-4f3c-8f4d-427de07e6de7

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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6,
7e6654c2-f192-439d-9be7-69a4adc7f88f,
8e59b87b-2264-4cca-993a-b137beaef0f4,
78e4be88-4707-457a-b232-e08e7fb191f7,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656,
354678be-2d77-43e5-acd3-527d66e47575,
89417684-5d59-4c2e-8b5c-9f4525a087c4,
dc38efa5-2fb1-4aed-ad8b-64362865f462,
daa6e92d-9722-4353-bd91-2aba17a2f098

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same first party: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e

result, different first party: null

unsupported: false

passed: true

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

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

result, same first party: 
a5df7538-e481-4697-83c2-d0c429d5a9c0,
2b2c596a-47f4-4a38-b4d7-f408027254b8

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

unsupported: false, false

passed: true, true

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

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

result, same first party: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

result, different first party: 
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

result, different first party: 
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.,
Error: The request was denied.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }

result, same first party: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
dc358174-9143-4559-8f1d-9c82f8aa667a,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
6bfe177c-474d-4f3c-8f4d-427de07e6de7

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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6,
7e6654c2-f192-439d-9be7-69a4adc7f88f,
8e59b87b-2264-4cca-993a-b137beaef0f4,
78e4be88-4707-457a-b232-e08e7fb191f7,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656,
354678be-2d77-43e5-acd3-527d66e47575,
89417684-5d59-4c2e-8b5c-9f4525a087c4,
dc38efa5-2fb1-4aed-ad8b-64362865f462,
daa6e92d-9722-4353-bd91-2aba17a2f098

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: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e

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

unsupported: false

passed: true

test failed: 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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0,
2b2c596a-47f4-4a38-b4d7-f408027254b8

result, different first party: 
Error: LockManager.query: query() is not allowed in this context,
Error: LockManager.query: query() is not allowed in this context

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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, 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

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

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

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

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

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

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

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

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same first party: Error: No requests received

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

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

unsupported: true, true

passed: undefined

test failed: 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
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, 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

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: 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

result, different first party: 2, 2

unsupported: false, false

passed: true, true

test failed: 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
ServiceWorker
The ServiceWorker API allows websites to run code in the background and store content in the browser for offline use. If a ServiceWorker can be accessed from multiple websites, it can be abused to track users across sites.
              
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: 
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: 
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

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
Unsupported
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

result, different first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

result, different first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 

result, different first party: 

unsupported: false

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

result, different first party: 
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined

unsupported: true, true

passed: undefined

test failed: false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }

read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }

result, same first party: 
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
,
<html>
<head><title>404 Not Found</title></head>
<body>
<center><h1>404 Not Found</h1></center>
<hr><center>nginx/1.18.0 (Ubuntu)</center>
</body>
</html>
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->
<!-- a padding to disable MSIE and Chrome friendly error page -->


result, different first party: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
SharedWorker
The SharedWorker API allows scripts from multiple tabs to share a background thread of computation. If SharedWorker is not partitioned, then it can be abused to shared data between websites in your browser.
              
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

result, different first party: 
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

result, different first party: 
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received,
Error: no SharedWorker message received

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
dc358174-9143-4559-8f1d-9c82f8aa667a,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
6bfe177c-474d-4f3c-8f4d-427de07e6de7

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 {
        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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6,
7e6654c2-f192-439d-9be7-69a4adc7f88f,
8e59b87b-2264-4cca-993a-b137beaef0f4,
78e4be88-4707-457a-b232-e08e7fb191f7,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656,
354678be-2d77-43e5-acd3-527d66e47575,
89417684-5d59-4c2e-8b5c-9f4525a087c4,
dc38efa5-2fb1-4aed-ad8b-64362865f462,
daa6e92d-9722-4353-bd91-2aba17a2f098

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }

result, same first party: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e

result, different first party: Error: Unsupported

unsupported: false

passed: true

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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0,
2b2c596a-47f4-4a38-b4d7-f408027254b8

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

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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: 
d6b32b18783c6f636b00726a5d0de36ee8b4ce5c5c6c44bbd1838f5302ad627e,
88e041852abdbd50a838c3ff8b10f65de0441724b727e57f2971319f882887a2,
561f82f30457eeb6e6cff47a74246f3be27a9070e04f66dda0715f0357e14353,
f13dcb61e0462d161bb0954dc0066c877e357873a2a72735dda0646a2f5e29be,
000dc0fb12d7903f41f39e217af83b50e7f36b73edfd91de4bd75284ab2ee60a

result, different first party: 
4344deacf4bc139acff93f3435ed67b90e9a98327dd74d5d318e66b1255f3818,
92ba909ad143e8e830e987dbf3ee97f5334ea6ec2b9215f0a3d1bb190d31c407,
24eb46e7f8c3b2147724eac53df62a3922dd0174ef778b3b08882b2ebaba3560,
37eb37b603bd2791399534bf2b7a919335d30f08b07bd4dfb6d87aca09d03073,
50d786ad4ba3d8534be7cb177ddcc8b6fdd814b0a89e72d3132af5ec865d1ddc

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: 
fc18ca44f2d9115afc8eeec4ebf7c80b547d67b21c3b3fba7a94f16f89953671,
d8ca4c99b9b15e9718c1decff5a3d25e6534e2dbdc634fad6126704bcb39ea86,
fab53d9dcfe5d37749670402a1877fb143f5618f80e2038344cdcfab253eb7aa,
33fcbdc6501cc5af1b08a223719a34869501fe830c1787399394f0755f140f09,
967a7feca6a6ecafcdd4668ede3d6f25b61dec8af7313f3ca6ce4b7b85e949b9

result, different first party: 
f741c7590504298ed7d834185836fae936d6a1fdf929c1f957aa1f0e5da303c9,
3b6d4689f149d742000efd1fa2eaa0d80a4530ff56863b5363841c4650b9ba55,
7f7beae628c4b27a6c8225dffa0cf7db39ec8866fea6312da9dae9cbe3dec9e7,
9e4f4bb6400d8bc5c273e584d253fe1a8498ad2d37d360fe55a441c02907b534,
cc4c27055c2ad08ab46ae1c22c41bea43625b7da48316c2f7f127fd2f21eb667

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: 
7261562b894b78b587196afb60d66ddaee137b7e35e80951eaddeb6477adf63c,
93be3be0bdb726e37b66e9a8c7be72039fa1d2fc6658a0dfe1d001c5dd29f6bc,
4b22fda9703e9de2943e38114b0ea2e8f0f5b276a3f8481fd7ba0d25daae359e,
b217152090d0d40a51271c998f1256d768748e07fb71814232e90f11c893428c,
7d99d444b2ff8b39b950326129f7d06f9635de4681383bc61efc6fadc3633d29

result, different first party: 
4a5d18ed242b2824ce1293f7efbba8f96cae852c49f550f5e380d67d6d7453be,
9cebee65dbd8cfbb9ef7fc879d4e8a610977e4f582db648695a3e30fff44cc34,
ae9a0b8d9e0d41c816e914fbdef5be5adbf88fe4c5145a332ab20101f376bc86,
b65e40c6b52ead9aa9c973f7e808097999abdac428e923bac815e7c3f816984b,
94ce9cdc34a8fd7c2341f05be4946b229619ba8093f03c8d8256c54dcd8c7f70

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: 
de2e4c8619a5c901cfd475dc9e870969270ce19a7e1512ce774cfaf0a8171a6a,
75f6d8f227cbbdd8681d33f3d5c7ab1f704e89920291479c4f481b8f0ae41381,
87abe2c97010d637c1329636b822d00573955eee9c721e2bb677708c6b162ed1,
999a298e421c0daebe2000cf3d8354647ce57b84677d3ba736fcdcb1346e6b9a,
ff3046709ac148e31f4fd8653a1d9afa910ff73cadcf6fe048406d7853bd3a33

result, different first party: 
04a0ead9838880909df6338c62a307b0d1069cec8f44bbb13c1dfab4d5d9ca85,
fef9e3800be12a4216c79ee934789f8c7f2291c76cc5ade515dad78ea3f6ef61,
42aba374defe6eabeba8495f42edb4cf018880c68e81210f33d190887bf49965,
e89831f955f25f47c67d6d2e3f62970033b13d0ea8e50967ff57a8eeadd1cb15,
ab22f602ce07c755cfcce2e281b05dc7c670e044897d3186754def697007466f

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: 
09df50f8b490bfd4254513bc032b25256d07dd2742fe5e5c9bb7b6305ef93e51,
d59eb9a36da556768c0960760f58f64b9ac1294935ae05eeaa8d17d47396370f,
1e54d4211545b874a59d114a1f8249d4d7c68b931c1c2187633fa2cad0b76517,
283067ad34198b83e01be3df217ee0cf08ec7e17a7520c550bfd6cb93824dbe3

result, different first party: 
ab6d74f5ef2895163e2c4eb701a6ad13a8170b1f14a75a02a27dfc92a0021523,
8c67e993e984df1bde02eaf4d9ccff1d26c1718b2d71075d7a283f6a9e37ef54,
9e8dc391a557d876e21e2181eaa0865b87821f4b778bd0afbdd067a9639ada85,
536f4dead95667263bcc87d66e3eb341e72385da485a06a7491d3d357a14a0ce

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: 
edc384e57af77df846e0672e5f6d12c2736512885114952e37fcf718b9bc8544,
36eb49040118e1f6e8a237703041da0174e3f16f7f0f799dec0eabf337541681,
54f3ce88d096ba5c1cd87f9262beb60f957b7c34c0796285a1991bc9cd49449b,
297ef28be42f675042f1ee1898d5d087322a11f1b81ad58e01ea6e86a9ba19f8,
00c92ae741ccefdbe21bad5082b30ab8ae741a3026a455688fd2c053efdeb9cc

result, different first party: 
26e84c827c44fcc879c80b1a71e30234d2baf740cbb05e8bc4865411b41cd4a9,
abfc048a8265aa155069eb4273b878d59c437c18d2b1d50af83c4c4e2daafb1e,
6af325e6e94780989fd939eb9408798699a43853826bbbd82bcd86fc63cbd3e9,
4c165d0616fac0045f70acebb3ebe53e4c8fda31bd54751460f1b05513087600,
8364b58d0712f1314631959c8982c033c2a35f25338c74fafb1a52b000b00050

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: 
6d05124a143b14c5a9584f4e92a7a040ec7f2d3d06fb36cb273ac8f3c9409c3a,
93533b9af35ac7996b92cc6faf9fa90701c6eedfd841fd5c400fb9aafae6e6e2,
803c16f5bf526cd7f261489e280e98765e6f1e93cb0ff84c3fdf2b88c5f33402,
0ba52cb2355050187ba09d2f51075807e410e3ec1c61cbaf7be5180a00838f5b,
26287fd0bcd7c4eceb9871c080bb45fcc2abe867aa1d5bf27285f0b66a99f4fc

result, different first party: 
f9fc861a0c795eeb0fe68ffd1db091331ebeaf16ccc95bd370761ccaa81879cc,
4658c87954f801b89f9900611dac17079454f48a7b6626c504dc5a6b1cedc351,
498cb61221e330ec497ab5ee5ca41ad8c90af56baf60f5f290c42561cdb175b3,
d8ba1e476c5c9f3245c61dc480afebf1ac8e1f5d4d1af0f754e4e4d0657d6a92,
4a0200886684f9999a618713f1c2e914f3bc31260ca6206b468c632ae0d73fd9

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: 
400fee5d20be225ec3236a273089df0e4d5c8ae60c36e10993c8cacc5bb22814,
666f44e9d1d161167e8f5886bf746fe3b897ec24d0d2a9f41d2197ae9c810d36,
716fb6e85f99a51bbeb090aa70c22e8e8709d1e344e7afdfb964b7314b812c05,
34c4a47122c9a850ac11184da459de2c777fc102989b0790f4ce122c84f101ae,
0c4296493bbc07765e8e228e9d437a6d0f3a7dc6d116a87d56d0e9cecdb474f3

result, different first party: 
b1f489cf36f2240bae43a825309af8db2973871c3e3fb167419906c1e2ef4be1,
c7a64558184145bc1a12037ad090df1fcd4826804a628da4c5410c2b28c63072,
5f840dea76dec09db38d3734ab1da21cf968fc7ba82884db2e7c23d9fd7e50ac,
2dad4eb1895376191f327ea79b03ef91fd20ab96c529d8a3a0693e2a22776103,
7774a867156f1390315fed29084b12aa5efd881706a730414d51aec6ebbef3b8

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: 35b36396a86c9017ba53e1b2508b929dbce9cd3c68714fdee146a09839d31798

result, different first party: 8fe07b9791c1917bb4b30ebd2db44b978e831b64154374ca49883785b575b628

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: 
51194b9ecad714277b195b3ade27a86a6eae8b089abcb84bdcdc9361812f6f53,
b9913441c85efd409d5e59994b1ca2e4b6ccb9c51b5e4bfc8a925475669a0b07

result, different first party: 
24ddf9294fd779931ec89ea79ba8bc336191007299a503ae28fbb73cdb3005da,
004b9c63170e550369c183a981656533b1a03022ac9b83bcafef439662dd8711

unsupported: false, false

passed: true, true

test failed: 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: 
b06066cf9098f4e2044b959ef0d82e0c4996a6bee256f58d5985e2221b6dfa58,
f42da31e62353dceb2fa771511b0f937e703fb077c0b2e5bf281faedebe62c72,
3b5c48953e310194244421080ace4dddeeed8cf4420b7c1fef1a5496e237fe6d,
ff411bbae4c8cd53a9a1cfed7520201e0dfa978d4879fe8719c86c9580ec2e8c,
9b907998e1a0770ff00ff5fb040208c29e9abe0d415aaa14c1252bbb197e6afe

result, different first party: 
14800ede21a6034acf89b007325de6c7c4d3cb02dd8aed5626a314694040bff0,
2febfb84a2dc6f4548756233425131b840d99633a92aafd2ea83edf5ec7dabf9,
054d78bfcfeb938f0b57d3aa2c250b6ba12dab9744775d318f815dcf2a140e7c,
b1eef8f37cc9c70fe61a6fe76fdfb43aaf9329e6fdae7e2639fe0614023a29cb,
124203ab333ae254219fd6eca516dbd5be2ae21e8135a73cb3f19dbbd5254226

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: 
9ff506b4e33cff9f8f0c535d1941fa131dca3e274357a59eafcd2216744c6a07,
225cefb4fe221743633ad6d12180c6913142fd604eb2e32e4f6f1ab40db17e8c,
d5072a6400daa6626c343733652028c70aa974cf992a98a4e2fb08d7894b758c,
4b8e8ca71f11b1442e7430d8d60d6843713dd2d081eae5468e74937cde4b892d,
8b71318831bd9da1affe0d487767d0f326035cdbfe203f16ebd9e68b4696e727

result, different first party: 
b680740e95ed43ec88f97d14550fa3751c14751857135e4f734a8e885845fb06,
e0ac4823c009afad5fbd06caeac74c1bd822bc738d2d61b5f88bd082e5adad4f,
33f5da0f4238f00d03a8504b49a8765e57b9e31f7a93bd9efcc7d6d0ba6c4beb,
8810f98b4811c6a885cabf97c41af39dde3b52a64be5d80858db6bdcd91809dd,
bff8f4d2aa9b33b3d7426737af05f500598133d44af8e4a0a4b671effebaf8be

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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 first party: 1, 1, 1, 1, 1

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

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

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

result, different first party: 2

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

result, different first party: 2, 2

unsupported: false, false

passed: true, true

test failed: false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

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

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Navigation testsWhich browsers prevent websites from sharing tracking data when you click on a link?
When you click a hyperlink to navigate your browser from one site to another, certain browser APIs allow the first site to communicate to the second site. These privacy vulnerabilities can be fixed by introducing new limits on how much data is transfered between sites.',
        
document.referrer
The Referer [sic] request header is a mechanism used by browsers to let a website know where the user is visiting from. This header is inherently tracking users across websites. In recent times, browsers have switched to a policy of trimming a referrer to convey less tracking information, but Referer continues to convey cross-site tracking data by default.
              
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

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

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/

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

unsupported: false

passed: false

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/

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

unsupported: false, false

passed: false, false

test failed: false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }

read: () => document.referrer

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

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

unsupported: false, false, false, false, false

passed: false, false, false, false, false

test failed: false, false, false, false, false
sessionStorage
The sessionStorage API is similar to the localStorage API, but it does not persist across tabs or across browser sessions. Nonetheless, it can be used to track users if they navigate from one website to another. This tracking can be thwarted by partitioning sessionStorage between websites.
              
Passed
write: (secret) => sessionStorage.setItem("secret", secret)

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

result, same first party: 
efe81322-bc41-43c1-9f2a-efc60712933b,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
b0e98059-2520-4716-bcc2-f2efe3980689,
f76831a6-090e-4a03-8c56-e81ef1fd258f,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d

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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
fa551d24-37e5-4566-ab64-de3420e474f5,
15dce9f3-092a-4c2b-8ff7-7500e17e339a,
c07732b1-a6b4-4367-b9a8-5b5d8c304091

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: 
2670a08e-e954-4bbe-b23f-224b90ca1075,
72eeaf18-bb23-4d8a-aebd-3a7114446cca,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
779edab1-e2d0-417b-9363-2c4b3c2cd06f,
54871a50-ba91-4267-8b5e-5200f05a2e8e

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: 
248c312b-c058-4c05-be9b-239817a7d9fa,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
a553c9a8-1901-4af8-8805-a66e0cb047ae,
4d81c129-5192-47a7-8e96-56f15a9a252d,
63487cfc-7648-4b4b-8b7b-df0b502173c1

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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
dc358174-9143-4559-8f1d-9c82f8aa667a,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
6bfe177c-474d-4f3c-8f4d-427de07e6de7

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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6,
7e6654c2-f192-439d-9be7-69a4adc7f88f,
8e59b87b-2264-4cca-993a-b137beaef0f4,
78e4be88-4707-457a-b232-e08e7fb191f7,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656,
354678be-2d77-43e5-acd3-527d66e47575,
89417684-5d59-4c2e-8b5c-9f4525a087c4,
dc38efa5-2fb1-4aed-ad8b-64362865f462,
daa6e92d-9722-4353-bd91-2aba17a2f098

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: 
551baa61-066c-4133-8848-693e3f38e45f,
46ffd76a-1163-4fce-973f-a95ac12666e2,
90eff2a5-3d6c-46ae-adcd-a281584af4ba,
4e123750-fbfb-4991-930d-efda2e2071ae,
dddb0ab1-3b3e-4b39-971e-014f4d8500de

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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e

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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0,
2b2c596a-47f4-4a38-b4d7-f408027254b8

result, different first party: , 

unsupported: false, false

passed: true, true

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

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

result, same first party: 
8922cf3e-a660-4a66-a121-e22a6decc694,
45bda111-36f5-4cba-af47-17f53bc255ef,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
d88a1655-b840-4fb7-88ac-68450644649a,
01fea522-8483-4538-8719-3849d0c0818c

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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d,
660baa93-30ce-41ff-bba6-879edeb0311b,
5acb01d8-0c36-4846-9204-26566e4e0798,
b78097b8-cd9a-4416-942d-8ca66805db24,
7f09e611-54ee-4b27-94da-b0894408819a

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_efe81322-bc41-43c1-9f2a-efc60712933b,
name_f0826ff3-1856-4e36-acb2-c6ad0ab498d9,
name_b0e98059-2520-4716-bcc2-f2efe3980689,
name_f76831a6-090e-4a03-8c56-e81ef1fd258f,
name_ea81f1e3-e0ae-4311-961f-3913bf9bf57d

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_0dc4a687-a8cc-42bb-ac9b-1b240d669085,
name_c7d3b4f4-1755-4d6d-9424-5f6c643b53f9,
name_fa551d24-37e5-4566-ab64-de3420e474f5,
name_15dce9f3-092a-4c2b-8ff7-7500e17e339a,
name_c07732b1-a6b4-4367-b9a8-5b5d8c304091

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_2670a08e-e954-4bbe-b23f-224b90ca1075,
name_72eeaf18-bb23-4d8a-aebd-3a7114446cca,
name_1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
name_779edab1-e2d0-417b-9363-2c4b3c2cd06f,
name_54871a50-ba91-4267-8b5e-5200f05a2e8e

result, different first party: 
name_2670a08e-e954-4bbe-b23f-224b90ca1075,
name_72eeaf18-bb23-4d8a-aebd-3a7114446cca,
name_1a5c7b81-4c1b-4236-8b31-edb58aef14ce,
name_779edab1-e2d0-417b-9363-2c4b3c2cd06f,
name_54871a50-ba91-4267-8b5e-5200f05a2e8e

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_248c312b-c058-4c05-be9b-239817a7d9fa,
name_d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
name_a553c9a8-1901-4af8-8805-a66e0cb047ae,
name_4d81c129-5192-47a7-8e96-56f15a9a252d,
name_63487cfc-7648-4b4b-8b7b-df0b502173c1

result, different first party: 
name_248c312b-c058-4c05-be9b-239817a7d9fa,
name_d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a,
name_a553c9a8-1901-4af8-8805-a66e0cb047ae,
name_4d81c129-5192-47a7-8e96-56f15a9a252d,
name_63487cfc-7648-4b4b-8b7b-df0b502173c1

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_1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7,
name_dc358174-9143-4559-8f1d-9c82f8aa667a,
name_dbdf861d-2be9-4a12-bc4a-d1c358e4cf14,
name_6bfe177c-474d-4f3c-8f4d-427de07e6de7

result, different first party: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

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

read: () => window.name

result, same first party: 
name_34cc24e5-703d-4cf1-92ed-da86f541e9a6,
name_7e6654c2-f192-439d-9be7-69a4adc7f88f,
name_8e59b87b-2264-4cca-993a-b137beaef0f4,
name_78e4be88-4707-457a-b232-e08e7fb191f7,
name_0cb7f3b3-97f1-483b-9b54-0ee683ced0a6

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_fafedf2e-7fa1-43d0-80c7-45ba53483656,
name_354678be-2d77-43e5-acd3-527d66e47575,
name_89417684-5d59-4c2e-8b5c-9f4525a087c4,
name_dc38efa5-2fb1-4aed-ad8b-64362865f462,
name_daa6e92d-9722-4353-bd91-2aba17a2f098

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_551baa61-066c-4133-8848-693e3f38e45f,
name_46ffd76a-1163-4fce-973f-a95ac12666e2,
name_90eff2a5-3d6c-46ae-adcd-a281584af4ba,
name_4e123750-fbfb-4991-930d-efda2e2071ae,
name_dddb0ab1-3b3e-4b39-971e-014f4d8500de

result, different first party: 
name_551baa61-066c-4133-8848-693e3f38e45f,
name_46ffd76a-1163-4fce-973f-a95ac12666e2,
name_90eff2a5-3d6c-46ae-adcd-a281584af4ba,
name_4e123750-fbfb-4991-930d-efda2e2071ae,
name_dddb0ab1-3b3e-4b39-971e-014f4d8500de

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_6abc00c2-61be-4d1a-862f-9793c19c2d8e

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_a5df7538-e481-4697-83c2-d0c429d5a9c0,
name_2b2c596a-47f4-4a38-b4d7-f408027254b8

result, different first party: , 

unsupported: false, false

passed: true, true

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

read: () => window.name

result, same first party: 
name_8922cf3e-a660-4a66-a121-e22a6decc694,
name_45bda111-36f5-4cba-af47-17f53bc255ef,
name_ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
name_d88a1655-b840-4fb7-88ac-68450644649a,
name_01fea522-8483-4538-8719-3849d0c0818c

result, different first party: 
name_8922cf3e-a660-4a66-a121-e22a6decc694,
name_45bda111-36f5-4cba-af47-17f53bc255ef,
name_ee343ad5-e7c4-4a0c-9feb-10a458bc788a,
name_d88a1655-b840-4fb7-88ac-68450644649a,
name_01fea522-8483-4538-8719-3849d0c0818c

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_0938d8d8-8acc-4701-98bd-35bd6ac7037d,
name_660baa93-30ce-41ff-bba6-879edeb0311b,
name_5acb01d8-0c36-4846-9204-26566e4e0798,
name_b78097b8-cd9a-4416-942d-8ca66805db24,
name_7f09e611-54ee-4b27-94da-b0894408819a

result, different first party: 
name_0938d8d8-8acc-4701-98bd-35bd6ac7037d,
name_660baa93-30ce-41ff-bba6-879edeb0311b,
name_5acb01d8-0c36-4846-9204-26566e4e0798,
name_b78097b8-cd9a-4416-942d-8ca66805db24,
name_7f09e611-54ee-4b27-94da-b0894408819a

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, true
result: 
Insecure website never loaded,
Insecure website never loaded,
Insecure website never loaded,
Insecure website never loaded,
Insecure website never loaded
Failed
passed: false, false, false, false, false
result: 
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false, false, false
result: 
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false, false
result: 
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Passed
passed: true, true, true, true, true
result: 
Insecure website never loaded,
Insecure website never loaded,
Insecure website never loaded,
Insecure website never loaded,
Insecure website never loaded
Passed
passed: true, true, true, true, true
result: 
Insecure website never loaded,
Insecure website never loaded,
Insecure website never loaded,
Insecure website never loaded,
Insecure website never loaded
Failed
passed: false, false, false, false, false
result: 
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false
result: Insecure website loaded
Passed
passed: true, true
result: 
Insecure website never loaded,
Insecure website never loaded
Failed
passed: false, false, false, false, false
result: 
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false, false, false
result: 
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Upgradable address
Checks to see if an insecure address entered into the browser's address bar is upgraded to HTTPS whenever possible.
              
Passed
upgraded: true, true, true, true, true
passed: true, true, true, true, true
Passed
upgraded: true, true, true, true, 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
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
Failed
upgraded: false
passed: false
Passed
upgraded: true, true
passed: true, true
Passed
upgraded: true, true, true, true, true
passed: true, true, true, true, true
Passed
upgraded: true, true, true, true, true
passed: true, true, true, true, true
Upgradable hyperlink
Checks to see if the user has clicked on a hyperlink to an insecure address, if the browser upgrades that address to HTTPS whenever possible.
              
Passed
upgraded: true, true, true, true, true
passed: true, true, true, true, true
Passed
upgraded: true, true, true, true, 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
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
Failed
upgraded: false
passed: false
Passed
upgraded: true, true
passed: true, true
Passed
upgraded: true, true, true, true, true
passed: true, true, true, true, true
Passed
upgraded: true, true, true, true, true
passed: true, true, true, true, true
Upgradable image
Checks to see if the browser attempts to upgrade an insecure address for an image to HTTPS whenever possible.
              
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Failed
passed: false, false, false, false
result: 
loaded insecurely,
loaded insecurely,
loaded insecurely,
loaded insecurely
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Failed
passed: false
result: loaded insecurely
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Upgradable script
Checks to see if the browser attempts to upgrade an insecure address for an script to HTTPS whenever possible.
              
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Passed
passed: true, true, true, true, 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
result: blocked, blocked, blocked, blocked
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Passed
passed: true
result: blocked
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Misc testsWhich browsers provide additional assorted privacy protections?
This category includes tests for the presence of miscellaneous privacy features
        
ECH enabled
Encrypted Client Hello (ECH) is a new protocol that hides the website you are visiting from third-party network eavesdroppers.
              
Passed
SNI_status: encrypted
passed: true, true, true, true, true
Failed
SNI_status: plaintext
passed: false, false, false, false, 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
Failed
SNI_status: plaintext
passed: false, false, false, false, false
Failed
SNI_status: plaintext
passed: false, false, false, false, false
Passed
SNI_status: encrypted
passed: true, true, true, true, true
Failed
SNI_status: plaintext
passed: false
Failed
SNI_status: plaintext
passed: false, false
Failed
SNI_status: plaintext
passed: false, true, true, true, true
Passed
SNI_status: encrypted
passed: true, true, true, true, true
GPC enabled first-party
The Global Privacy Control is an HTTP header that can be sent by a browser to instruct a website not to sell the user's personal data to third parties. This test checks to see if the GPC header is sent by default to the top-level website.
              
Passed
header value: 1
passed: true, true, true, true, true
Passed
header value: 1
passed: true, true, true, true, 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
Passed
header value: 1
passed: true, true, true, true, true
Failed
header value: undefined
passed: false, false, false, false, false
Failed
header value: undefined
passed: false, false, false, false, false
Failed
header value: undefined
passed: false
Failed
header value: undefined
passed: false, false
Failed
header value: undefined
passed: false, false, false, false, false
Failed
header value: undefined
passed: false, false, false, false, false
GPC enabled third-party
The Global Privacy Control is an HTTP header that can be sent by a browser to instruct a visited website not to sell the user's personal data to other parties. This test checks to see if the GPC header is sent to third-party elements on the web page.
              
Passed
sec-gpc: 1
passed: true, true, true, true, true
Passed
sec-gpc: 1
passed: true, true, true, true, true
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Passed
sec-gpc: 1
passed: true, true, true, true
Passed
sec-gpc: 1
passed: true, true, true, true, true
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false
Failed
passed: false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
IP address leak
IP addresses can be used to uniquely identify a large percentage of users. A proxy, VPN, or Tor can mask a user's IP address.
              
Failed
passed: false, false, false, false, false
Passed
passed: true, true, true, true, true
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: 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
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Stream isolation
Browsers that use Tor can use a different Tor circuit per top-level website.
              
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true, true, true, true, true
readSameFirstParty: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Failed
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: false, false, false, false, false
readSameFirstParty: 
192.42.116.177,
72.167.47.69,
107.189.30.236,
89.234.157.254,
185.220.100.240
readDifferentFirstParty: 
192.42.116.177,
72.167.47.69,
107.189.30.236,
89.234.157.254,
185.220.100.240
passed: false, false, false, false, false
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
readSameFirstParty: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
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
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
readSameFirstParty: 
217.160.88.146,
45.141.215.169
readDifferentFirstParty: 
2a0b:f4c2:4::97,
2a00:1b88:4::4
passed: true, true
testFailed: false, false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true, true, true, true, true
readSameFirstParty: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Unsupported
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: true, true, true, true, true
readSameFirstParty: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Tor enabled
The Tor network sends the browser's web requests through a series of relays to hide a user's IP address, thereby helping to mask their identity and location. This test checks to see if the Tor network is being used by default.
              
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Passed
IsTorExit: true, true, true, true, true
passed: true, true, true, true, true
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Failed
IsTorExit: false, false, false, false
passed: 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
passed: true, true
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Fingerprinting resistance testsWhich browsers hide what's unique about your device?
Fingerprinting is a technique trackers use to uniquely identify you as you browse the web. A fingerprinting script will measure several characteristics of your browser and, combining this data, will build a fingerprint that may uniquely identify you among web users. Browsers can introduce countermeasures, such as minimizing the distinguishing information disclosed by certain web APIs so your browser is harder to pick out from the crowd (so-called 'fingerprinting resistance').`,
        
Media query screen height
Height of the user's screen in pixels.
              
Passed
expression: undefined
desired expression: undefined
actual value: 1290,1291,1296,1294,1294
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 1291,1291,1294,1290,1294
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 1440
desired value: undefined
passed: false
Passed
expression: undefined
desired expression: undefined
actual value: 900,900
desired value: undefined
passed: true,true
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Media query screen width
Width of the user's screen in pixels.
              
Passed
expression: undefined
desired expression: undefined
actual value: 1208,1201,1205,1200,1200
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 1204,1205,1205,1206,1201
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: 1600,1600,1600,1600,1600
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 1400,1400,1400,1400,1400
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 2560
desired value: undefined
passed: false
Passed
expression: undefined
desired expression: undefined
actual value: 1400,1400
desired value: undefined
passed: true,true
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
outerHeight
Height of the browser window in pixels, including browser chrome.
              
Passed
expression: outerHeight
desired expression: undefined
actual value: 1290,1291,1296,1294,1294
desired value: undefined
passed: true,true,true,true,true
Passed
expression: outerHeight
desired expression: undefined
actual value: 1291,1291,1294,1290,1294
desired value: undefined
passed: true,true,true,true,true
Failed
expression: outerHeight
desired expression: undefined
actual value: 1371,1371,1371,1371,1371
desired value: undefined
passed: false,false,false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 1371,1371,1371,1371,1371
desired value: undefined
passed: false,false,false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 1040,1040,1040,1040
desired value: undefined
passed: false,false,false,false
Passed
expression: outerHeight
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Passed
expression: outerHeight
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Failed
expression: outerHeight
desired expression: undefined
actual value: 1061,1061,1061,1061,1061
desired value: undefined
passed: false,false,false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 1335
desired value: undefined
passed: false
Passed
expression: outerHeight
desired expression: undefined
actual value: 900,900
desired value: undefined
passed: true,true
Failed
expression: outerHeight
desired expression: undefined
actual value: 1371,1371,1371,1371,1371
desired value: undefined
passed: false,false,false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 1371,1371,1371,1371,1371
desired value: undefined
passed: false,false,false,false,false
screen.height
Height of the user's screen, in pixels.
              
Passed
expression: screen.height
desired expression: undefined
actual value: 1290,1291,1296,1294,1294
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screen.height
desired expression: undefined
actual value: 1291,1291,1294,1290,1294
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false
Passed
expression: screen.height
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screen.height
desired expression: undefined
actual value: 900,900,900,900,900
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 1440
desired value: undefined
passed: false
Passed
expression: screen.height
desired expression: undefined
actual value: 900,900
desired value: undefined
passed: true,true
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 1440,1440,1440,1440,1440
desired value: undefined
passed: false,false,false,false,false
screen.width
Width of the user's screen, in pixels.
              
Passed
expression: screen.width
desired expression: undefined
actual value: 1208,1201,1205,1200,1200
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screen.width
desired expression: undefined
actual value: 1204,1205,1205,1206,1201
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false
Passed
expression: screen.width
desired expression: undefined
actual value: 1600,1600,1600,1600,1600
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screen.width
desired expression: undefined
actual value: 1400,1400,1400,1400,1400
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 2560
desired value: undefined
passed: false
Passed
expression: screen.width
desired expression: undefined
actual value: 1400,1400
desired value: undefined
passed: true,true
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 2560,2560,2560,2560,2560
desired value: undefined
passed: false,false,false,false,false
screenX
Position, in pixels, of the left edge of the browser window on screen.
              
Passed
expression: screenX
desired expression: undefined
actual value: 8,7,6,6,5
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 8,1,7,4,1
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screenX
desired expression: undefined
actual value: 22,22,22,22,22
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenX
desired expression: undefined
actual value: 22,22,22,22,22
desired value: undefined
passed: false,false,false,false,false
Passed
expression: screenX
desired expression: undefined
actual value: 4,4,4,4
desired value: undefined
passed: true,true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0,0,0
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0,0,0
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screenX
desired expression: undefined
actual value: 320,320,320,320,320
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenX
desired expression: undefined
actual value: 1358
desired value: undefined
passed: false
Passed
expression: screenX
desired expression: undefined
actual value: 0,0
desired value: undefined
passed: true,true
Failed
expression: screenX
desired expression: undefined
actual value: 22,22,22,22,22
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenX
desired expression: undefined
actual value: 22,22,22,22,22
desired value: undefined
passed: false,false,false,false,false
screenY
Position, in pixels, of the top edge of the browser window on screen.
              
Passed
expression: screenY
desired expression: undefined
actual value: 5,2,7,8,5
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 6,5,0,3,7
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screenY
desired expression: undefined
actual value: 47,47,47,47,47
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenY
desired expression: undefined
actual value: 47,47,47,47,47
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenY
desired expression: undefined
actual value: 25,25,25,25
desired value: undefined
passed: false,false,false,false
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0,0,0
desired value: undefined
passed: true,true,true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0,0,0
desired value: undefined
passed: true,true,true,true,true
Failed
expression: screenY
desired expression: undefined
actual value: 202,202,202,202,202
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenY
desired expression: undefined
actual value: 54
desired value: undefined
passed: false
Passed
expression: screenY
desired expression: undefined
actual value: 0,0
desired value: undefined
passed: true,true
Failed
expression: screenY
desired expression: undefined
actual value: 47,47,47,47,47
desired value: undefined
passed: false,false,false,false,false
Failed
expression: screenY
desired expression: undefined
actual value: 47,47,47,47,47
desired value: undefined
passed: false,false,false,false,false
System font detection
Web pages can detect the presence of a font installed on the user's system. The presence or absence of various fonts is commonly used to fingerprint users.
              
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false,false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true,true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false,false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true
Passed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: true,true
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false,false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false,false,false,false
Tracking query parameter testsWhich browsers remove URL parameters that can track you?
When you browse from one web page to another, tracking companies will frequently attach a 'tracking query parameter' to the address of the second web page. That query parameter may contain a unique identifier that tracks you individually as you browse the web. And these query parameters are frequently synchronized with cookies, making them a powerful tracking vector. Web browsers can protect you from known tracking query parameters by stripping them from web addresses before your browser sends them. (The set of tracking query parameters tested here was largely borrowed from Brave.)`
        
__hsfp
HubSpot tracking parameter
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
__hssc
HubSpot tracking parameter
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
__hstc
HubSpot tracking parameter
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
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, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
_hsenc
HubSpot tracking parameter
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
_openstat
Yandex tracking parameter
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
dclid
DoubleClick Click ID (Google)
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
fbclid
Facebook Click Identifier
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
gclid
Google Click Identifier
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
hsCtaTracking
HubSpot tracking parameter
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
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, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
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, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
ml_subscriber
MailerLite email tracking
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Failed
value: 01752447911282684
passed: false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
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, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Failed
value: 01752447911282684
passed: false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
msclkid
Microsoft Click ID
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
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, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
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, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
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, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Failed
value: 01752447911282684
passed: false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
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, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Failed
value: 01752447911282684
passed: false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
vero_conv
Vero tracking parameter
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Failed
value: 01752447911282684
passed: false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
vero_id
Vero tracking parameter
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
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, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
yclid
Yandex Click ID
              
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false, false, false, false
Passed
passed: true, true, true, true, true
Passed
passed: true, true, true, true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
passed: false
Passed
passed: true, true
Failed
value: 01752447911282684
passed: false, false, false, false, false
Failed
value: 01752447911282684
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, 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
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true, true, true, true, true
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true, true, true, true, true
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false, false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false, false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false, false, false
Adobe Audience Manager
Tests whether the browser blocks the page from loading the tracker at https://dpm.demdex.net/ibs
              
Passed
url: https://dpm.demdex.net/ibs
passed: true, true, true, true, true
Passed
url: https://dpm.demdex.net/ibs
passed: true, true, true, true, 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
Passed
url: https://dpm.demdex.net/ibs
passed: true, true, true, true, true
Passed
url: https://dpm.demdex.net/ibs
passed: true, true, true, true, true
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false, false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false, false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false, false, false
Amazon adsystem
Tests whether the browser blocks the page from loading the tracker at https://s.amazon-adsystem.com/dcm
              
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true, true, true, true
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true, true, true, 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
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true, true, true, true
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true, true, true, true
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false, false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false, false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false, false, false
AppNexus
Tests whether the browser blocks the page from loading the tracker at https://ib.adnxs.com/px?id=178248&t=1
              
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true, true, true, true
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true, true, true, 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
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true, true, true, true
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true, true, true, true
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false, false, false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false, false, false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false, false, false
Bing Ads
Tests whether the browser blocks the page from loading the tracker at https://bat.bing.com/bat.js
              
Passed
url: https://bat.bing.com/bat.js
passed: true, true, true, true, true
Passed
url: https://bat.bing.com/bat.js
passed: true, true, true, true, 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
Passed
url: https://bat.bing.com/bat.js
passed: true, true, true, true, true
Passed
url: https://bat.bing.com/bat.js
passed: true, true, true, true, true
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false, false, false
Failed
url: https://bat.bing.com/bat.js
passed: false
Failed
url: https://bat.bing.com/bat.js
passed: false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false, false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false, false, false
Chartbeat
Tests whether the browser blocks the page from loading the tracker at https://static.chartbeat.com/js/chartbeat.js
              
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
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
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
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Criteo
Tests whether the browser blocks the page from loading the tracker at https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
              
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true, true, true, true
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true, true, true, 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
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true, true, true, true
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true, true, true, true
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false, false, false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false, false, false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false, false, false
DoubleClick (Google)
Tests whether the browser blocks the page from loading the tracker at https://securepubads.g.doubleclick.net/static/glade.js
              
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true, true, true, true
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true, true, true, 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
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true, true, true, true
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true, true, true, true
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false, false, false, false, false
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false, false
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false, false, false, false, false
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false, false, false, false, false
Facebook tracking
Tests whether the browser blocks the page from loading the tracker at https://connect.facebook.net/en_US/fbevents.js
              
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true, true, true, true
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true, true, true, 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
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true, true, true, true
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true, true, true, true
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false, false, false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false, false, false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false, false, false
Google (third-party ad pixel)
Tests whether the browser blocks the page from loading the tracker at https://www.google.com/pagead/1p-user-list/
              
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true, true, true, true, true
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true, true, true, true, 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
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true, true, true, true, true
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true, true, true, true, true
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false, false, false, false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false, false, false, false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false, false, false, false
Google Analytics
Tests whether the browser blocks the page from loading the tracker at https://google-analytics.com/urchin.js
              
Passed
url: https://google-analytics.com/urchin.js
passed: true, true, true, true, true
Passed
url: https://google-analytics.com/urchin.js
passed: true, true, true, true, 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
Passed
url: https://google-analytics.com/urchin.js
passed: true, true, true, true, true
Passed
url: https://google-analytics.com/urchin.js
passed: true, true, true, true, true
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false, false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false, false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false, false, false
Google Tag Manager
Tests whether the browser blocks the page from loading the tracker at https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
              
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true, true, true, true, true
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true, true, true, true, 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
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true, true, true, true, true
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true, true, true, true, true
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, false, false, false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, false, false, false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, false, false, false
Index Exchange
Tests whether the browser blocks the page from loading the tracker at https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
              
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true, true, true, true, true
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true, true, true, true, 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
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true, true, true, true, true
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true, true, true, true, true
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false, false, false, false, false
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false, false
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false, false, false, false, false
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false, false, false, false, false
New Relic
Tests whether the browser blocks the page from loading the tracker at https://js-agent.newrelic.com/nr-1212.min.js
              
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true, true, true, true
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true, true, true, 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
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true, true, true, true
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true, true, true, true
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false, false, false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false, false, false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false, false, false
Quantcast
Tests whether the browser blocks the page from loading the tracker at https://pixel.quantserve.com/pixel
              
Passed
url: https://pixel.quantserve.com/pixel
passed: true, true, true, true, true
Passed
url: https://pixel.quantserve.com/pixel
passed: true, true, true, true, 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
Passed
url: https://pixel.quantserve.com/pixel
passed: true, true, true, true, true
Passed
url: https://pixel.quantserve.com/pixel
passed: true, true, true, true, true
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false, false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false, false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false, false, false
Scorecard Research Beacon
Tests whether the browser blocks the page from loading the tracker at https://sb.scorecardresearch.com/internal-c2/default/cs.js
              
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true, true, true, true
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true, true, true, 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
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true, true, true, true
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true, true, true, true
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false, false, false, false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false, false, false, false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false, false, false, false
Taboola
Tests whether the browser blocks the page from loading the tracker at https://trc.taboola.com/futureplc-tomsguide/trc/3/json
              
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true, true, true, true, true
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true, true, true, true, 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
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true, true, true, true, true
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true, true, true, true, true
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false, false, false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false, false, false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false, false, false
Twitter pixel
Tests whether the browser blocks the page from loading the tracker at https://t.co/i/adsct
              
Passed
url: https://t.co/i/adsct
passed: true, true, true, true, true
Passed
url: https://t.co/i/adsct
passed: true, true, true, true, 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
Passed
url: https://t.co/i/adsct
passed: true, true, true, true, true
Passed
url: https://t.co/i/adsct
passed: true, true, true, true, true
Failed
url: https://t.co/i/adsct
passed: false, false, false, false, false
Failed
url: https://t.co/i/adsct
passed: false
Failed
url: https://t.co/i/adsct
passed: false, false
Failed
url: https://t.co/i/adsct
passed: false, false, false, false, false
Failed
url: https://t.co/i/adsct
passed: false, false, false, false, false
Yandex Ads
Tests whether the browser blocks the page from loading the tracker at https://yandex.ru/ads/system/header-bidding.js
              
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true, true, true, true, true
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true, true, true, true, 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
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true, true, true, true, true
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true, true, true, true, true
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false, false, false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false, false, false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false, false, false
Tracking cookie protection testsWhich browsers block important known tracking cookies?
A large fraction of web pages on the web have hidden third-party trackers that read and write cookies in your browser. These cookies can be used to track your browsing across websites. This section checks to see if a browser stops cross-site tracking by cookies from 20 of the largest trackers listed by https://whotracks.me.`,
        
Adobe
Tests whether the browser stops cookies from munchkin.marketo.net from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false
Passed
passed: true, true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://munchkin.marketo.net/munchkin.js
cookieFound: false, false, false, false, false
Adobe Audience Manager
Tests whether the browser stops cookies from dpm.demdex.net from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://dpm.demdex.net/ibs
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://dpm.demdex.net/ibs
cookieFound: false
Passed
passed: true, true
url: https://dpm.demdex.net/ibs
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://dpm.demdex.net/ibs
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://dpm.demdex.net/ibs
cookieFound: false, false, false, false, false
Amazon adsystem
Tests whether the browser stops cookies from s.amazon-adsystem.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://s.amazon-adsystem.com/dcm
cookieFound: false
Passed
passed: true, true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://s.amazon-adsystem.com/dcm
cookieFound: false, false, false, false, false
AppNexus
Tests whether the browser stops cookies from ib.adnxs.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false
Passed
passed: true, true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://ib.adnxs.com/px?id=178248&t=1
cookieFound: false, false, false, false, false
Bing Ads
Tests whether the browser stops cookies from bat.bing.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://bat.bing.com/bat.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://bat.bing.com/bat.js
cookieFound: false
Passed
passed: true, true
url: https://bat.bing.com/bat.js
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://bat.bing.com/bat.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://bat.bing.com/bat.js
cookieFound: false, false, false, false, false
Chartbeat
Tests whether the browser stops cookies from static.chartbeat.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
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
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
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://static.chartbeat.com/js/chartbeat.js
cookieFound: false, false, false, false, false
Criteo
Tests whether the browser stops cookies from dis.criteo.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false
Passed
passed: true, true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
cookieFound: false, false, false, false, false
DoubleClick (Google)
Tests whether the browser stops cookies from securepubads.g.doubleclick.net from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false
Passed
passed: true, true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://securepubads.g.doubleclick.net/static/glade.js
cookieFound: false, false, false, false, false
Facebook tracking
Tests whether the browser stops cookies from connect.facebook.net from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false
Passed
passed: true, true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://connect.facebook.net/en_US/fbevents.js
cookieFound: false, false, false, false, false
Google (third-party ad pixel)
Tests whether the browser stops cookies from www.google.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false
Passed
passed: true, true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://www.google.com/pagead/1p-user-list/
cookieFound: false, false, false, false, false
Google Analytics
Tests whether the browser stops cookies from google-analytics.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://google-analytics.com/urchin.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
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
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
url: https://google-analytics.com/urchin.js
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://google-analytics.com/urchin.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://google-analytics.com/urchin.js
cookieFound: false, false, false, false, false
Google Tag Manager
Tests whether the browser stops cookies from www.googletagmanager.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
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
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
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
cookieFound: false, false, false, false, false
Index Exchange
Tests whether the browser stops cookies from dsum-sec.casalemedia.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false
Passed
passed: true, true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
cookieFound: false, false, false, false, false
New Relic
Tests whether the browser stops cookies from js-agent.newrelic.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
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
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
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://js-agent.newrelic.com/nr-1212.min.js
cookieFound: false, false, false, false, false
Quantcast
Tests whether the browser stops cookies from pixel.quantserve.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://pixel.quantserve.com/pixel
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://pixel.quantserve.com/pixel
cookieFound: false
Passed
passed: true, true
url: https://pixel.quantserve.com/pixel
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://pixel.quantserve.com/pixel
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://pixel.quantserve.com/pixel
cookieFound: false, false, false, false, false
Scorecard Research Beacon
Tests whether the browser stops cookies from sb.scorecardresearch.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
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
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
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
cookieFound: false, false, false, false, false
Taboola
Tests whether the browser stops cookies from trc.taboola.com from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false
Passed
passed: true, true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
cookieFound: false, false, false, false, false
Twitter pixel
Tests whether the browser stops cookies from t.co from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://t.co/i/adsct
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
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
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
url: https://t.co/i/adsct
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://t.co/i/adsct
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://t.co/i/adsct
cookieFound: false, false, false, false, false
Yandex Ads
Tests whether the browser stops cookies from yandex.ru from tracking users across websites.
              
Passed
passed: true, true, true, true, true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, 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
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
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false
Passed
passed: true, true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false, false
Passed
passed: true, true, true, true, true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false, false, false, false, false
Passed
passed: true, true, true, true, true
url: https://yandex.ru/ads/system/header-bidding.js
cookieFound: false, false, false, false, false
Cross-session first-party tracking testsWhich browsers prevent websites from tracking you across browser sessions?
A common vulnerability of web browsers is that they allow websites ("first parties") to 'tag' your browser with some tracking data. This tag can be used to re-identify you when you return to a website you visited before. This category of leaks can be prevented by browser if they clean or isolate data between browser sessions. (In cases where a user has logged into a website or entered detailed information, it may be justifiable for a browser to retain information across sessions. These tests check when no such justification exists: when you have entered no significant information into a website, will the browser still retain data that allows you to be tracked across sessions?)
        
Alt-Svc
Alt-Svc allows the server to indicate to the web browser that a resource should be loaded on a different server. Because this is a persistent setting, it could be used to track users across websites if it is not correctly partitioned.
              
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

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

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: h2, h2, h2, h2, h2

result, different session: h2, h2, h2, h2, h2

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
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

result, different session: h2, h2, h2, h2

unsupported: false, false, false, false

passed: true, true, true, true

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

result, different session: h2

unsupported: false

passed: true

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

result, different session: h2, h2

unsupported: true, true

passed: undefined

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

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

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
efe81322-bc41-43c1-9f2a-efc60712933b_1p,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_1p,
b0e98059-2520-4716-bcc2-f2efe3980689_1p,
f76831a6-090e-4a03-8c56-e81ef1fd258f_1p,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_1p,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_1p,
fa551d24-37e5-4566-ab64-de3420e474f5_1p,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_1p,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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: 
2670a08e-e954-4bbe-b23f-224b90ca1075_1p,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_1p,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_1p,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_1p,
54871a50-ba91-4267-8b5e-5200f05a2e8e_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: 
248c312b-c058-4c05-be9b-239817a7d9fa_1p,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_1p,
a553c9a8-1901-4af8-8805-a66e0cb047ae_1p,
4d81c129-5192-47a7-8e96-56f15a9a252d_1p,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_1p,
dc358174-9143-4559-8f1d-9c82f8aa667a_1p,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_1p,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_1p

result, different session: 
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined

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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_1p,
7e6654c2-f192-439d-9be7-69a4adc7f88f_1p,
8e59b87b-2264-4cca-993a-b137beaef0f4_1p,
78e4be88-4707-457a-b232-e08e7fb191f7_1p,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_1p

result, different session: 
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 
551baa61-066c-4133-8848-693e3f38e45f_1p,
46ffd76a-1163-4fce-973f-a95ac12666e2_1p,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_1p,
4e123750-fbfb-4991-930d-efda2e2071ae_1p,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_1p

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

unsupported: false

passed: true

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.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true

passed: undefined

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694_1p,
45bda111-36f5-4cba-af47-17f53bc255ef_1p,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_1p,
d88a1655-b840-4fb7-88ac-68450644649a_1p,
01fea522-8483-4538-8719-3849d0c0818c_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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_1p,
660baa93-30ce-41ff-bba6-879edeb0311b_1p,
5acb01d8-0c36-4846-9204-26566e4e0798_1p,
b78097b8-cd9a-4416-942d-8ca66805db24_1p,
7f09e611-54ee-4b27-94da-b0894408819a_1p

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

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
efe81322-bc41-43c1-9f2a-efc60712933b_1p_http,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_1p_http,
b0e98059-2520-4716-bcc2-f2efe3980689_1p_http,
f76831a6-090e-4a03-8c56-e81ef1fd258f_1p_http,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_1p_http,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_1p_http,
fa551d24-37e5-4566-ab64-de3420e474f5_1p_http,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_1p_http,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
2670a08e-e954-4bbe-b23f-224b90ca1075_1p_http,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_1p_http,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_1p_http,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_1p_http,
54871a50-ba91-4267-8b5e-5200f05a2e8e_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
248c312b-c058-4c05-be9b-239817a7d9fa_1p_http,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_1p_http,
a553c9a8-1901-4af8-8805-a66e0cb047ae_1p_http,
4d81c129-5192-47a7-8e96-56f15a9a252d_1p_http,
63487cfc-7648-4b4b-8b7b-df0b502173c1_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_1p_http,
dc358174-9143-4559-8f1d-9c82f8aa667a_1p_http,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_1p_http,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_1p_http

result, different session: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

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

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

result, same session: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_1p_http,
7e6654c2-f192-439d-9be7-69a4adc7f88f_1p_http,
8e59b87b-2264-4cca-993a-b137beaef0f4_1p_http,
78e4be88-4707-457a-b232-e08e7fb191f7_1p_http,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
fafedf2e-7fa1-43d0-80c7-45ba53483656_1p_http,
354678be-2d77-43e5-acd3-527d66e47575_1p_http,
89417684-5d59-4c2e-8b5c-9f4525a087c4_1p_http,
dc38efa5-2fb1-4aed-ad8b-64362865f462_1p_http,
daa6e92d-9722-4353-bd91-2aba17a2f098_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
551baa61-066c-4133-8848-693e3f38e45f_1p_http,
46ffd76a-1163-4fce-973f-a95ac12666e2_1p_http,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_1p_http,
4e123750-fbfb-4991-930d-efda2e2071ae_1p_http,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_1p_http

result, different session: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_1p_http

unsupported: false

passed: false

test failed: 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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0_1p_http,
2b2c596a-47f4-4a38-b4d7-f408027254b8_1p_http

result, different session: , 

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694_1p_http,
45bda111-36f5-4cba-af47-17f53bc255ef_1p_http,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_1p_http,
d88a1655-b840-4fb7-88ac-68450644649a_1p_http,
01fea522-8483-4538-8719-3849d0c0818c_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_1p_http,
660baa93-30ce-41ff-bba6-879edeb0311b_1p_http,
5acb01d8-0c36-4846-9204-26566e4e0798_1p_http,
b78097b8-cd9a-4416-942d-8ca66805db24_1p_http,
7f09e611-54ee-4b27-94da-b0894408819a_1p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
efe81322-bc41-43c1-9f2a-efc60712933b_1p_js,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_1p_js,
b0e98059-2520-4716-bcc2-f2efe3980689_1p_js,
f76831a6-090e-4a03-8c56-e81ef1fd258f_1p_js,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_1p_js,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_1p_js,
fa551d24-37e5-4566-ab64-de3420e474f5_1p_js,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_1p_js,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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: 
2670a08e-e954-4bbe-b23f-224b90ca1075_1p_js,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_1p_js,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_1p_js,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_1p_js,
54871a50-ba91-4267-8b5e-5200f05a2e8e_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: 
248c312b-c058-4c05-be9b-239817a7d9fa_1p_js,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_1p_js,
a553c9a8-1901-4af8-8805-a66e0cb047ae_1p_js,
4d81c129-5192-47a7-8e96-56f15a9a252d_1p_js,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_1p_js,
dc358174-9143-4559-8f1d-9c82f8aa667a_1p_js,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_1p_js,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_1p_js,
7e6654c2-f192-439d-9be7-69a4adc7f88f_1p_js,
8e59b87b-2264-4cca-993a-b137beaef0f4_1p_js,
78e4be88-4707-457a-b232-e08e7fb191f7_1p_js,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656_1p_js,
354678be-2d77-43e5-acd3-527d66e47575_1p_js,
89417684-5d59-4c2e-8b5c-9f4525a087c4_1p_js,
dc38efa5-2fb1-4aed-ad8b-64362865f462_1p_js,
daa6e92d-9722-4353-bd91-2aba17a2f098_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: 
551baa61-066c-4133-8848-693e3f38e45f_1p_js,
46ffd76a-1163-4fce-973f-a95ac12666e2_1p_js,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_1p_js,
4e123750-fbfb-4991-930d-efda2e2071ae_1p_js,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_1p_js

result, different session: null

unsupported: false

passed: true

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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0_1p_js,
2b2c596a-47f4-4a38-b4d7-f408027254b8_1p_js

result, different session: , 

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694_1p_js,
45bda111-36f5-4cba-af47-17f53bc255ef_1p_js,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_1p_js,
d88a1655-b840-4fb7-88ac-68450644649a_1p_js,
01fea522-8483-4538-8719-3849d0c0818c_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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_1p_js,
660baa93-30ce-41ff-bba6-879edeb0311b_1p_js,
5acb01d8-0c36-4846-9204-26566e4e0798_1p_js,
b78097b8-cd9a-4416-942d-8ca66805db24_1p_js,
7f09e611-54ee-4b27-94da-b0894408819a_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: 
efe81322-bc41-43c1-9f2a-efc60712933b_1p,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_1p,
b0e98059-2520-4716-bcc2-f2efe3980689_1p,
f76831a6-090e-4a03-8c56-e81ef1fd258f_1p,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_1p,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_1p,
fa551d24-37e5-4566-ab64-de3420e474f5_1p,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_1p,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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: 
2670a08e-e954-4bbe-b23f-224b90ca1075_1p,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_1p,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_1p,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_1p,
54871a50-ba91-4267-8b5e-5200f05a2e8e_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: 
248c312b-c058-4c05-be9b-239817a7d9fa_1p,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_1p,
a553c9a8-1901-4af8-8805-a66e0cb047ae_1p,
4d81c129-5192-47a7-8e96-56f15a9a252d_1p,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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

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: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

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

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

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

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 
551baa61-066c-4133-8848-693e3f38e45f_1p,
46ffd76a-1163-4fce-973f-a95ac12666e2_1p,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_1p,
4e123750-fbfb-4991-930d-efda2e2071ae_1p,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_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

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

unsupported: true, true

passed: undefined

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694_1p,
45bda111-36f5-4cba-af47-17f53bc255ef_1p,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_1p,
d88a1655-b840-4fb7-88ac-68450644649a_1p,
01fea522-8483-4538-8719-3849d0c0818c_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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_1p,
660baa93-30ce-41ff-bba6-879edeb0311b_1p,
5acb01d8-0c36-4846-9204-26566e4e0798_1p,
b78097b8-cd9a-4416-942d-8ca66805db24_1p,
7f09e611-54ee-4b27-94da-b0894408819a_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_5474228067289362,
fake_5086212112522341,
fake_06836651204634125,
fake_5880595816770928,
fake_7797567831465351

result, different session: 
fake_5971849580709068,
fake_486311278505698,
fake_7897974030725947,
fake_5184644077535874,
fake_12071334595787864

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_0025664677748222786,
fake_5793361754036292,
fake_2605462726212353,
fake_06153011979072187,
fake_42944751687848703

result, different session: 
fake_44856043755820596,
fake_12464891423347901,
fake_2387942431049388,
fake_52621352982461,
fake_35649236941413154

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_305924816163367,
fake_7297478479246755,
fake_8965034498438504,
fake_034684162840160404,
fake_4154997662151556

result, different session: 
fake_6667281406049503,
fake_05007538512256149,
fake_00708578991033848,
fake_6625561347514448,
fake_2940385456115391

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_5217024732137452,
fake_8079324146103655,
fake_834237905955304,
fake_6875237442652375,
fake_15407367799765437

result, different session: 
fake_8800191342378654,
fake_8701611573519863,
fake_6923945067943642,
fake_6595530196041199,
fake_7352393968849076

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_7023454300223078,
fake_006596452828969479,
fake_2702207781749879,
fake_7269647948027145

result, different session: 
fake_6569660756039057,
fake_5092169718647492,
fake_062103930947805086,
fake_2607120155296594

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_5780391058003431,
fake_2414196392714556,
fake_22600758104007856,
fake_49870894018169176,
fake_2721308459958349

result, different session: 
fake_19463665331640168,
fake_16454937429842365,
fake_1082262317958893,
fake_5650071674292898,
fake_16832355076722338

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_8107030139960374,
fake_7249246464746559,
fake_11626397568887836,
fake_3959351607334065,
fake_9366598493414091

result, different session: 
fake_8142584517742752,
fake_6560073359185117,
fake_7668831627032082,
fake_6153032360464818,
fake_02690238376342613

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_514251171007998,
fake_5467295288441789,
fake_9250589003527938,
fake_8197321518110545,
fake_8918471628659157

result, different session: 
fake_7786498498914085,
fake_3944273918266683,
fake_9514722558720767,
fake_615028755274311,
fake_2183010108519532

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: fake_5284324448782325

result, different session: fake_5284324448782325

unsupported: false

passed: false

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_047467419896156215,
fake_06037465723098179

result, different session: 
fake_3376826068957983,
fake_33093370609776307

unsupported: false, false

passed: true, true

test failed: 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_04932633351736526,
fake_838146046753409,
fake_9645239281824884,
fake_006647560528006746,
fake_3163055434233233

result, different session: 
fake_1399915696056877,
fake_6956026201741452,
fake_5281958726817995,
fake_1261909140381161,
fake_1487912660257278

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_515452100046081,
fake_286449695275403,
fake_07383655333204531,
fake_054840941215857475,
fake_6220573782050713

result, different session: 
fake_24802582509024118,
fake_7538535210903174,
fake_2098201505556736,
fake_16117551056792312,
fake_4889057340231444

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, 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

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
Failed
write: (key) => key

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

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 2, 2, 2, 2, 2

result, different session: 4, 4, 4, 4, 4

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 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

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

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

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 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

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

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

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 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

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

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

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 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

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

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

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
indexedDB
The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
              
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
efe81322-bc41-43c1-9f2a-efc60712933b_1p,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_1p,
b0e98059-2520-4716-bcc2-f2efe3980689_1p,
f76831a6-090e-4a03-8c56-e81ef1fd258f_1p,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_1p,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_1p,
fa551d24-37e5-4566-ab64-de3420e474f5_1p,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_1p,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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: 
2670a08e-e954-4bbe-b23f-224b90ca1075_1p,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_1p,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_1p,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_1p,
54871a50-ba91-4267-8b5e-5200f05a2e8e_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: 
248c312b-c058-4c05-be9b-239817a7d9fa_1p,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_1p,
a553c9a8-1901-4af8-8805-a66e0cb047ae_1p,
4d81c129-5192-47a7-8e96-56f15a9a252d_1p,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_1p,
dc358174-9143-4559-8f1d-9c82f8aa667a_1p,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_1p,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_1p,
7e6654c2-f192-439d-9be7-69a4adc7f88f_1p,
8e59b87b-2264-4cca-993a-b137beaef0f4_1p,
78e4be88-4707-457a-b232-e08e7fb191f7_1p,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656_1p,
354678be-2d77-43e5-acd3-527d66e47575_1p,
89417684-5d59-4c2e-8b5c-9f4525a087c4_1p,
dc38efa5-2fb1-4aed-ad8b-64362865f462_1p,
daa6e92d-9722-4353-bd91-2aba17a2f098_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: 
551baa61-066c-4133-8848-693e3f38e45f_1p,
46ffd76a-1163-4fce-973f-a95ac12666e2_1p,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_1p,
4e123750-fbfb-4991-930d-efda2e2071ae_1p,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_1p

result, different session: undefined

unsupported: false

passed: true

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: 
a5df7538-e481-4697-83c2-d0c429d5a9c0_1p,
2b2c596a-47f4-4a38-b4d7-f408027254b8_1p

result, different session: undefined

unsupported: false, false

passed: true, true

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694_1p,
45bda111-36f5-4cba-af47-17f53bc255ef_1p,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_1p,
d88a1655-b840-4fb7-88ac-68450644649a_1p,
01fea522-8483-4538-8719-3849d0c0818c_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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_1p,
660baa93-30ce-41ff-bba6-879edeb0311b_1p,
5acb01d8-0c36-4846-9204-26566e4e0798_1p,
b78097b8-cd9a-4416-942d-8ca66805db24_1p,
7f09e611-54ee-4b27-94da-b0894408819a_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: 
efe81322-bc41-43c1-9f2a-efc60712933b_1p,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_1p,
b0e98059-2520-4716-bcc2-f2efe3980689_1p,
f76831a6-090e-4a03-8c56-e81ef1fd258f_1p,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_1p,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_1p,
fa551d24-37e5-4566-ab64-de3420e474f5_1p,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_1p,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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: 
2670a08e-e954-4bbe-b23f-224b90ca1075_1p,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_1p,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_1p,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_1p,
54871a50-ba91-4267-8b5e-5200f05a2e8e_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: 
248c312b-c058-4c05-be9b-239817a7d9fa_1p,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_1p,
a553c9a8-1901-4af8-8805-a66e0cb047ae_1p,
4d81c129-5192-47a7-8e96-56f15a9a252d_1p,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_1p,
dc358174-9143-4559-8f1d-9c82f8aa667a_1p,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_1p,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_1p,
7e6654c2-f192-439d-9be7-69a4adc7f88f_1p,
8e59b87b-2264-4cca-993a-b137beaef0f4_1p,
78e4be88-4707-457a-b232-e08e7fb191f7_1p,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_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: 
fafedf2e-7fa1-43d0-80c7-45ba53483656_1p,
354678be-2d77-43e5-acd3-527d66e47575_1p,
89417684-5d59-4c2e-8b5c-9f4525a087c4_1p,
dc38efa5-2fb1-4aed-ad8b-64362865f462_1p,
daa6e92d-9722-4353-bd91-2aba17a2f098_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: 
551baa61-066c-4133-8848-693e3f38e45f_1p,
46ffd76a-1163-4fce-973f-a95ac12666e2_1p,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_1p,
4e123750-fbfb-4991-930d-efda2e2071ae_1p,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_1p

result, different session: null

unsupported: false

passed: true

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

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

result, same session: 
a5df7538-e481-4697-83c2-d0c429d5a9c0_1p,
2b2c596a-47f4-4a38-b4d7-f408027254b8_1p

result, different session: , 

unsupported: false, false

passed: true, true

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

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

result, same session: 
8922cf3e-a660-4a66-a121-e22a6decc694_1p,
45bda111-36f5-4cba-af47-17f53bc255ef_1p,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_1p,
d88a1655-b840-4fb7-88ac-68450644649a_1p,
01fea522-8483-4538-8719-3849d0c0818c_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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_1p,
660baa93-30ce-41ff-bba6-879edeb0311b_1p,
5acb01d8-0c36-4846-9204-26566e4e0798_1p,
b78097b8-cd9a-4416-942d-8ca66805db24_1p,
7f09e611-54ee-4b27-94da-b0894408819a_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, 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

result, different session: 2, 2, 2, 2

unsupported: false, false, false, false

passed: true, true, true, true

test failed: false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

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

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

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

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

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

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: Error: No requests received

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

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

unsupported: true, true

passed: undefined

test failed: 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
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, 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

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
Failed
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

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

test failed: 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
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, 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

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
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

test failed: false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Cross-session third-party tracking testsWhich browsers prevent third-party trackers from tracking you across browser sessions?
A common vulnerability of web browsers is that they allow third-party trackers to 'tag' your browser with some tracking data. This tag can be used to re-identify you when you return to a website you visited before. This category of leaks can be prevented by browser if they clean or isolate data between browser sessions. (In cases where a user has logged into a website or entered detailed information, it may be justifiable for a browser to retain information across sessions. These tests check when no such justification exists: when you have entered no significant information into a website, will the browser still retain data that allows you to be tracked across sessions?)
        
Alt-Svc
Alt-Svc allows the server to indicate to the web browser that a resource should be loaded on a different server. Because this is a persistent setting, it could be used to track users across websites if it is not correctly partitioned.
              
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }

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

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: h2, h2, h2, h2, h2

result, different session: 
Error: Failed to fetch,
h2,
h2,
h2,
h2

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
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

result, different session: h2, h2, h2, h2

unsupported: false, false, false, false

passed: true, true, true, true

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
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: h3

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

result, different session: h2, h2

unsupported: true, true

passed: undefined

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

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

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: h3, h3, h3, h3, h3

result, different session: h2, h2, h2, h2, h2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

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

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

unsupported: true, true, true, true, true

passed: undefined

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

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

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

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

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
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: 
2670a08e-e954-4bbe-b23f-224b90ca1075_3p,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_3p,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_3p,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_3p,
54871a50-ba91-4267-8b5e-5200f05a2e8e_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: 
248c312b-c058-4c05-be9b-239817a7d9fa_3p,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_3p,
a553c9a8-1901-4af8-8805-a66e0cb047ae_3p,
4d81c129-5192-47a7-8e96-56f15a9a252d_3p,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_3p,
dc358174-9143-4559-8f1d-9c82f8aa667a_3p,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_3p,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_3p

result, different session: 
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined

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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_3p,
7e6654c2-f192-439d-9be7-69a4adc7f88f_3p,
8e59b87b-2264-4cca-993a-b137beaef0f4_3p,
78e4be88-4707-457a-b232-e08e7fb191f7_3p,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_3p

result, different session: 
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 
551baa61-066c-4133-8848-693e3f38e45f_3p,
46ffd76a-1163-4fce-973f-a95ac12666e2_3p,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_3p,
4e123750-fbfb-4991-930d-efda2e2071ae_3p,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_3p

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

unsupported: false

passed: true

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.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true

passed: undefined

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694_3p,
45bda111-36f5-4cba-af47-17f53bc255ef_3p,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_3p,
d88a1655-b840-4fb7-88ac-68450644649a_3p,
01fea522-8483-4538-8719-3849d0c0818c_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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_3p,
660baa93-30ce-41ff-bba6-879edeb0311b_3p,
5acb01d8-0c36-4846-9204-26566e4e0798_3p,
b78097b8-cd9a-4416-942d-8ca66805db24_3p,
7f09e611-54ee-4b27-94da-b0894408819a_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: 
efe81322-bc41-43c1-9f2a-efc60712933b_3p_http,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_3p_http,
b0e98059-2520-4716-bcc2-f2efe3980689_3p_http,
f76831a6-090e-4a03-8c56-e81ef1fd258f_3p_http,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_3p_http,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_3p_http,
fa551d24-37e5-4566-ab64-de3420e474f5_3p_http,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_3p_http,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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
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: 
248c312b-c058-4c05-be9b-239817a7d9fa_3p_http,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_3p_http,
a553c9a8-1901-4af8-8805-a66e0cb047ae_3p_http,
4d81c129-5192-47a7-8e96-56f15a9a252d_3p_http,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_3p_http,
dc358174-9143-4559-8f1d-9c82f8aa667a_3p_http,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_3p_http,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_3p_http

result, different session: , , , 

unsupported: false, false, false, false

passed: true, true, true, true

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

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

result, same session: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_3p_http,
7e6654c2-f192-439d-9be7-69a4adc7f88f_3p_http,
8e59b87b-2264-4cca-993a-b137beaef0f4_3p_http,
78e4be88-4707-457a-b232-e08e7fb191f7_3p_http,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_3p_http

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 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

passed: undefined

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 
efe81322-bc41-43c1-9f2a-efc60712933b_3p_js,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_3p_js,
b0e98059-2520-4716-bcc2-f2efe3980689_3p_js,
f76831a6-090e-4a03-8c56-e81ef1fd258f_3p_js,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_3p_js,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_3p_js,
fa551d24-37e5-4566-ab64-de3420e474f5_3p_js,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_3p_js,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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
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: 
248c312b-c058-4c05-be9b-239817a7d9fa_3p_js,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_3p_js,
a553c9a8-1901-4af8-8805-a66e0cb047ae_3p_js,
4d81c129-5192-47a7-8e96-56f15a9a252d_3p_js,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_3p_js,
dc358174-9143-4559-8f1d-9c82f8aa667a_3p_js,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_3p_js,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_3p_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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_3p_js,
7e6654c2-f192-439d-9be7-69a4adc7f88f_3p_js,
8e59b87b-2264-4cca-993a-b137beaef0f4_3p_js,
78e4be88-4707-457a-b232-e08e7fb191f7_3p_js,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_3p_js

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 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

passed: undefined

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 
efe81322-bc41-43c1-9f2a-efc60712933b_3p,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_3p,
b0e98059-2520-4716-bcc2-f2efe3980689_3p,
f76831a6-090e-4a03-8c56-e81ef1fd258f_3p,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_3p,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_3p,
fa551d24-37e5-4566-ab64-de3420e474f5_3p,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_3p,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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: , , , , 

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: 
248c312b-c058-4c05-be9b-239817a7d9fa_3p,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_3p,
a553c9a8-1901-4af8-8805-a66e0cb047ae_3p,
4d81c129-5192-47a7-8e96-56f15a9a252d_3p,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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

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: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

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

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported

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

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: Error: Unsupported

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

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

unsupported: true, true

passed: undefined

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: , , , , 

result, different session: , , , , 

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 
fake_5142258363659362,
fake_7905978607903494,
fake_7933545412772223,
fake_9395011437999314,
fake_10552811213848279

result, different session: 
fake_1329252094484663,
fake_8413126657827448,
fake_7473639505112546,
fake_3408783477162738,
fake_9807546623127721

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_5787570351006042,
fake_9957240289134732,
fake_7050459469014436,
fake_07370379501550484,
fake_33450097204059115

result, different session: 
fake_8699838268627302,
fake_4166457653079496,
fake_2026273929838407,
fake_561802217177471,
fake_5440523266270361

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_28966964252693383,
fake_019738868423635925,
fake_3884794423595914,
fake_3026989896488237,
fake_21116842823011917

result, different session: 
fake_02770001359112806,
fake_445206081498315,
fake_8507394664761683,
fake_38505583108535846,
fake_1445563145464106

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_24423137107378023,
fake_5947352967463477,
fake_7784068819036742,
fake_14168102747476197,
fake_354730440289875

result, different session: 
fake_19630652290041928,
fake_6194442771574682,
fake_26816814356026986,
fake_018369321307787123,
fake_8643184801978085

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_10188406546600337,
fake_45316188521851997,
fake_4064922610525814,
fake_163069519719369

result, different session: 
fake_25461297486181933,
fake_7826559812400349,
fake_5765902128759299,
fake_00263234715279137

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_525697280872585,
fake_4914158368798154,
fake_3308952008736914,
fake_03169459280044351,
fake_050332893765114184

result, different session: 
fake_5197401843835763,
fake_872694563507505,
fake_637385736855582,
fake_22097037074162262,
fake_9670416780589692

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_18488438020929387,
fake_2502030518319045,
fake_2683365376747091,
fake_7248663093703105,
fake_8087949491518249

result, different session: 
fake_4648658074340024,
fake_041421707932709495,
fake_7017614718518339,
fake_5024384303483311,
fake_933439467324982

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_680690460760317,
fake_844066890585081,
fake_2975040022484827,
fake_1777914731169914,
fake_13013746794042746

result, different session: 
fake_2606656256254123,
fake_8483828980753987,
fake_31363922059893556,
fake_9296586936441933,
fake_6416494500337637

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: fake_1496021251235089

result, different session: fake_1496021251235089

unsupported: false

passed: false

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_8577219154589086,
fake_1646002783964462

result, different session: 
fake_7768316845734149,
fake_8565790868112695

unsupported: false, false

passed: true, true

test failed: 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_940434799095289,
fake_8512545867592445,
fake_8339308883520102,
fake_4928335509846047,
fake_8523630452590649

result, different session: 
fake_727231085370313,
fake_7031015297524859,
fake_4276050347582858,
fake_876907741383099,
fake_7112944488061061

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_43470683062190996,
fake_010300034033267513,
fake_08918988781105197,
fake_8899897290173191,
fake_3124359912318382

result, different session: 
fake_8813179180751272,
fake_5547876454555138,
fake_043540409643271216,
fake_8767071765600045,
fake_799603164994934

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, 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

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
Failed
write: (key) => key

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

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 1, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: false, true, true, true, true

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

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

result, same session: 2, 2, 2, 2, 2

result, different session: 2, 4, 4, 4, 4

unsupported: false, false, false, false, false

passed: false, 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, 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

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

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

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 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

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

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

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 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

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

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

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 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

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

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

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
indexedDB
The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
              
Unsupported
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

result, different session: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

result, different session: 
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
2670a08e-e954-4bbe-b23f-224b90ca1075_3p,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_3p,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_3p,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_3p,
54871a50-ba91-4267-8b5e-5200f05a2e8e_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: 
248c312b-c058-4c05-be9b-239817a7d9fa_3p,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_3p,
a553c9a8-1901-4af8-8805-a66e0cb047ae_3p,
4d81c129-5192-47a7-8e96-56f15a9a252d_3p,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_3p,
dc358174-9143-4559-8f1d-9c82f8aa667a_3p,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_3p,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_3p,
7e6654c2-f192-439d-9be7-69a4adc7f88f_3p,
8e59b87b-2264-4cca-993a-b137beaef0f4_3p,
78e4be88-4707-457a-b232-e08e7fb191f7_3p,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_3p

result, different session: undefined

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }

read: () => IdbKeyVal.get("secret")

result, same session: 
551baa61-066c-4133-8848-693e3f38e45f_3p,
46ffd76a-1163-4fce-973f-a95ac12666e2_3p,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_3p,
4e123750-fbfb-4991-930d-efda2e2071ae_3p,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_3p

result, different session: undefined

unsupported: false

passed: true

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.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true

passed: undefined

test failed: 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: 
8922cf3e-a660-4a66-a121-e22a6decc694_3p,
45bda111-36f5-4cba-af47-17f53bc255ef_3p,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_3p,
d88a1655-b840-4fb7-88ac-68450644649a_3p,
01fea522-8483-4538-8719-3849d0c0818c_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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_3p,
660baa93-30ce-41ff-bba6-879edeb0311b_3p,
5acb01d8-0c36-4846-9204-26566e4e0798_3p,
b78097b8-cd9a-4416-942d-8ca66805db24_3p,
7f09e611-54ee-4b27-94da-b0894408819a_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: 
efe81322-bc41-43c1-9f2a-efc60712933b_3p,
f0826ff3-1856-4e36-acb2-c6ad0ab498d9_3p,
b0e98059-2520-4716-bcc2-f2efe3980689_3p,
f76831a6-090e-4a03-8c56-e81ef1fd258f_3p,
ea81f1e3-e0ae-4311-961f-3913bf9bf57d_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: 
0dc4a687-a8cc-42bb-ac9b-1b240d669085_3p,
c7d3b4f4-1755-4d6d-9424-5f6c643b53f9_3p,
fa551d24-37e5-4566-ab64-de3420e474f5_3p,
15dce9f3-092a-4c2b-8ff7-7500e17e339a_3p,
c07732b1-a6b4-4367-b9a8-5b5d8c304091_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: 
2670a08e-e954-4bbe-b23f-224b90ca1075_3p,
72eeaf18-bb23-4d8a-aebd-3a7114446cca_3p,
1a5c7b81-4c1b-4236-8b31-edb58aef14ce_3p,
779edab1-e2d0-417b-9363-2c4b3c2cd06f_3p,
54871a50-ba91-4267-8b5e-5200f05a2e8e_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: 
248c312b-c058-4c05-be9b-239817a7d9fa_3p,
d6b220c7-b43f-4ea5-8108-1dbf7ab46e0a_3p,
a553c9a8-1901-4af8-8805-a66e0cb047ae_3p,
4d81c129-5192-47a7-8e96-56f15a9a252d_3p,
63487cfc-7648-4b4b-8b7b-df0b502173c1_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: 
1a6d4de5-b9ea-4a44-8c3d-ca077f2310f7_3p,
dc358174-9143-4559-8f1d-9c82f8aa667a_3p,
dbdf861d-2be9-4a12-bc4a-d1c358e4cf14_3p,
6bfe177c-474d-4f3c-8f4d-427de07e6de7_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: 
34cc24e5-703d-4cf1-92ed-da86f541e9a6_3p,
7e6654c2-f192-439d-9be7-69a4adc7f88f_3p,
8e59b87b-2264-4cca-993a-b137beaef0f4_3p,
78e4be88-4707-457a-b232-e08e7fb191f7_3p,
0cb7f3b3-97f1-483b-9b54-0ee683ced0a6_3p

result, different session: , , , , 

unsupported: false, false, false, false, false

passed: true, true, true, true, true

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

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

result, same session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true, true, true, true

passed: undefined

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

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

result, same session: 
551baa61-066c-4133-8848-693e3f38e45f_3p,
46ffd76a-1163-4fce-973f-a95ac12666e2_3p,
90eff2a5-3d6c-46ae-adcd-a281584af4ba_3p,
4e123750-fbfb-4991-930d-efda2e2071ae_3p,
dddb0ab1-3b3e-4b39-971e-014f4d8500de_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: 6abc00c2-61be-4d1a-862f-9793c19c2d8e_3p

result, different session: null

unsupported: false

passed: true

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.

result, different session: 
Error: The operation is insecure.,
Error: The operation is insecure.

unsupported: true, true

passed: undefined

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

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

result, same session: 
8922cf3e-a660-4a66-a121-e22a6decc694_3p,
45bda111-36f5-4cba-af47-17f53bc255ef_3p,
ee343ad5-e7c4-4a0c-9feb-10a458bc788a_3p,
d88a1655-b840-4fb7-88ac-68450644649a_3p,
01fea522-8483-4538-8719-3849d0c0818c_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: 
0938d8d8-8acc-4701-98bd-35bd6ac7037d_3p,
660baa93-30ce-41ff-bba6-879edeb0311b_3p,
5acb01d8-0c36-4846-9204-26566e4e0798_3p,
b78097b8-cd9a-4416-942d-8ca66805db24_3p,
7f09e611-54ee-4b27-94da-b0894408819a_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, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

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

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
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

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

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

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

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

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

unsupported: true, true, true, true, true

passed: undefined

test failed: false, false, false, false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: 1, 1, 1, 1, 1

result, different session: 2, 2, 2, 2, 2

unsupported: false, false, false, false, false

passed: true, true, true, true, true

test failed: false, false, false, false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }

read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }

result, same session: Error: No requests received

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

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

unsupported: true, true

passed: undefined

test failed: 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
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, 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

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
Failed
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

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

test failed: 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
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, 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

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
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }

read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }

result, same session: 1

result, different session: 1

unsupported: false

passed: false

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

result, different session: 2, 2

unsupported: false, false

passed: true, true

test failed: 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
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, 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, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false
leak detected: 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
leak detected: 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
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, 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, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false
leak detected: 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
leak detected: 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
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, 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, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false
leak detected: 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
leak detected: 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
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, 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, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false
leak detected: 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
leak detected: 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
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, 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, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false
leak detected: 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
leak detected: 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
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, 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, 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
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
leak detected: 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
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, 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, 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
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
leak detected: 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
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, 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
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
Failed
passed: false, true, false, false, false
leak detected: true, false, true, true, true
Passed
passed: true
leak detected: false
Passed
passed: true, true
leak detected: false, false
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
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, 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, false, false, false, false
leak detected: true, true, true, true, true
Failed
passed: false, false, false, false
leak detected: 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
leak detected: 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
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, 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
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
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true
leak detected: false
Passed
passed: true, true
leak detected: false, false
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
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, 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, false, false, false, false
leak detected: true, true, true, true, true
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
Failed
passed: false, false, false, false, false
leak detected: true, true, true, true, true
Passed
passed: true
leak detected: false
Passed
passed: true, true
leak detected: 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