Android Browsers

(default settings)
brave logo
brave
1.73
chrome logo
chrome
131.0
cromite logo
cromite
130.0
duckduckgo logo
duckduckgo
5.222
edge logo
edge
131.0
firefox logo
firefox
133.0
focus logo
focus
133.0
opera logo
opera
86.4
samsung logo
samsung
27.0
tor logo
tor
14.0
vivaldi logo
vivaldi
7.0
yandex logo
yandex
24.12
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
result, different first party: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: h2, h2
unsupported: true, true
passed: undefined
test failed: false, false
Failed
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
result, different first party: h3, h3, h3
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different first party: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: h2, h2, h2
unsupported: true, true, true
passed: undefined
test failed: 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
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
result, different first party: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: h2, h2
unsupported: false, false
passed: true, true
test failed: 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=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.
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.
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.
result, different first party:
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.
result, different first party:
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.
unsupported: false, false
passed: undefined
test failed: true, true
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false
passed: true, true
test failed: 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:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false
passed: undefined
test failed: true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: The operation is insecure.,
Error: The operation is insecure.
unsupported: false, false
passed: undefined
test failed: true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false
passed: undefined
test failed: true, true
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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
143d61f8-2894-4529-ad80-0a53e9ebc6cc,
143d61f8-2894-4529-ad80-0a53e9ebc6cc,
143d61f8-2894-4529-ad80-0a53e9ebc6cc
result, different first party:
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
ff5789e9-e545-4690-9fea-1af9b462597e,
ff5789e9-e545-4690-9fea-1af9b462597e,
ff5789e9-e545-4690-9fea-1af9b462597e
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')
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
2f149f9d-7d24-4463-baa9-df54b4e81d63,
2f149f9d-7d24-4463-baa9-df54b4e81d63
result, different first party:
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p,
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p,
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p
result, different first party:
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p,
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p,
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0
result, different first party:
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
39122539-ac2b-4685-b7fc-0e032c9e090b,
39122539-ac2b-4685-b7fc-0e032c9e090b,
39122539-ac2b-4685-b7fc-0e032c9e090b
result, different first party:
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
cee0a24e-86b6-4713-865e-7c8c9dbc0330,
7e3c6442-4764-430e-ac99-8d3376daab80,
916da71a-153b-4626-878f-ff051279512b
result, different first party:
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
c97b5d06-2396-4bb1-9f7d-6fde65072b04,
c97b5d06-2396-4bb1-9f7d-6fde65072b04,
c97b5d06-2396-4bb1-9f7d-6fde65072b04
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')
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
a31f089a-366d-46aa-8a3d-39c59eae3ef3_3p,
a31f089a-366d-46aa-8a3d-39c59eae3ef3_3p,
a31f089a-366d-46aa-8a3d-39c59eae3ef3_3p
result, different first party:
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
c6728d83-23bd-4322-814e-ddcad72e88c4,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5
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 (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
1af58a1e-55c5-4125-ba6b-5729d21fd23c,
1af58a1e-55c5-4125-ba6b-5729d21fd23c,
1af58a1e-55c5-4125-ba6b-5729d21fd23c
result, different first party:
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
4f69eb13-b603-4269-81bb-78ce896b6e33_3p,
4f69eb13-b603-4269-81bb-78ce896b6e33_3p
result, different first party:
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')
unsupported: false, false
passed: true, true
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
9978c55e-bfb4-434b-b846-23d42090a687_http,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_http,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_http
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_http,
f2da4c27-b927-49c2-9e18-25f272c9328f_http,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_http
result, different first party:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_http,
f2da4c27-b927-49c2-9e18-25f272c9328f_http,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_http
unsupported: false, false, false
passed: false, false, false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
c7054ae3-6667-4a7e-a612-ca3225829997_http,
c98891bc-9d3d-40e1-963c-02a2e673d255_http
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
a57cc61c-4dad-4d58-8993-b1599b60f30d_http,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_http,
c3405b81-ce4e-47fb-9288-741b29aece7c_http
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_http,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_http,
6df13641-2d34-4529-b349-3c5772849016_http
result, different first party:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_http,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_http,
6df13641-2d34-4529-b349-3c5772849016_http
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
03ddb668-d164-434b-8703-85d4fc2e66dc_http,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_http,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_http
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_http,
7e3c6442-4764-430e-ac99-8d3376daab80_http,
916da71a-153b-4626-878f-ff051279512b_http
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_http,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_http,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_http
result, different first party:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_http,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_http,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_http
unsupported: false, false, false
passed: false, false, false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
bef24721-ae28-44cf-b4e7-18ba6b47af22_http,
b752f8b5-1d43-4024-b85c-d0610aaad620_http,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_http
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
c6728d83-23bd-4322-814e-ddcad72e88c4_http,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5_http
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
0f00b752-b58d-4191-84f3-6ca6518adaf2_http,
2233c25f-133b-4283-8605-f1b3293a7bd9_http,
42b37351-62ab-4493-8ca7-365d6a7f4847_http
result, different first party:
0f00b752-b58d-4191-84f3-6ca6518adaf2_http,
2233c25f-133b-4283-8605-f1b3293a7bd9_http,
42b37351-62ab-4493-8ca7-365d6a7f4847_http
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
2769613e-97f8-44a3-837f-189b84b9e278_http,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_http
result, different first party:
2769613e-97f8-44a3-837f-189b84b9e278_http,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_http
unsupported: false, false
passed: false, false
test failed: 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=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
9978c55e-bfb4-434b-b846-23d42090a687_js,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_js,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_js
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_js,
f2da4c27-b927-49c2-9e18-25f272c9328f_js,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_js
result, different first party:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_js,
f2da4c27-b927-49c2-9e18-25f272c9328f_js,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
c7054ae3-6667-4a7e-a612-ca3225829997_js,
c98891bc-9d3d-40e1-963c-02a2e673d255_js
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
a57cc61c-4dad-4d58-8993-b1599b60f30d_js,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_js,
c3405b81-ce4e-47fb-9288-741b29aece7c_js
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_js,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_js,
6df13641-2d34-4529-b349-3c5772849016_js
result, different first party:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_js,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_js,
6df13641-2d34-4529-b349-3c5772849016_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
03ddb668-d164-434b-8703-85d4fc2e66dc_js,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_js,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_js
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_js,
7e3c6442-4764-430e-ac99-8d3376daab80_js,
916da71a-153b-4626-878f-ff051279512b_js
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_js,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_js,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_js
result, different first party:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_js,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_js,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
bef24721-ae28-44cf-b4e7-18ba6b47af22_js,
b752f8b5-1d43-4024-b85c-d0610aaad620_js,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_js
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
c6728d83-23bd-4322-814e-ddcad72e88c4_js,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5_js
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
0f00b752-b58d-4191-84f3-6ca6518adaf2_js,
2233c25f-133b-4283-8605-f1b3293a7bd9_js,
42b37351-62ab-4493-8ca7-365d6a7f4847_js
result, different first party:
0f00b752-b58d-4191-84f3-6ca6518adaf2_js,
2233c25f-133b-4283-8605-f1b3293a7bd9_js,
42b37351-62ab-4493-8ca7-365d6a7f4847_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
2769613e-97f8-44a3-837f-189b84b9e278_js,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_js
result, different first party:
2769613e-97f8-44a3-837f-189b84b9e278_js,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_js
unsupported: false, false
passed: false, false
test failed: 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:
9978c55e-bfb4-434b-b846-23d42090a687,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: 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:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1,
f2da4c27-b927-49c2-9e18-25f272c9328f,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc
result, different first party:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1,
f2da4c27-b927-49c2-9e18-25f272c9328f,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc
unsupported: false, false, false
passed: false, false, false
test failed: 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:
c7054ae3-6667-4a7e-a612-ca3225829997,
c98891bc-9d3d-40e1-963c-02a2e673d255
result, different first party: ,
unsupported: false, false
passed: true, true
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:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: 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:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c,
715f3890-7ef6-4e6d-8c5e-f67837724eb4,
6df13641-2d34-4529-b349-3c5772849016
result, different first party:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c,
715f3890-7ef6-4e6d-8c5e-f67837724eb4,
6df13641-2d34-4529-b349-3c5772849016
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: true, true, true
passed: undefined
test failed: 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
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: true, true, true
passed: undefined
test failed: 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:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5,
c2905ef6-4c9e-4027-8a34-105ee0be95a2,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572
result, different first party:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5,
c2905ef6-4c9e-4027-8a34-105ee0be95a2,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572
unsupported: false, false, false
passed: false, false, false
test failed: 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:
bef24721-ae28-44cf-b4e7-18ba6b47af22,
b752f8b5-1d43-4024-b85c-d0610aaad620,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party:
Error: Unsupported,
Error: Unsupported
unsupported: true, true
passed: undefined
test failed: 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:
0f00b752-b58d-4191-84f3-6ca6518adaf2,
2233c25f-133b-4283-8605-f1b3293a7bd9,
42b37351-62ab-4493-8ca7-365d6a7f4847
result, different first party:
0f00b752-b58d-4191-84f3-6ca6518adaf2,
2233c25f-133b-4283-8605-f1b3293a7bd9,
42b37351-62ab-4493-8ca7-365d6a7f4847
unsupported: false, false, false
passed: false, false, false
test failed: 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:
2769613e-97f8-44a3-837f-189b84b9e278,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306
result, different first party:
2769613e-97f8-44a3-837f-189b84b9e278,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306
unsupported: false, false
passed: false, false
test failed: 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_054592321342699535,
fake_956919120871953,
fake_8229939879478254
result, different first party:
fake_23144733763967262,
fake_4136132852561927,
fake_7414173947322802
unsupported: false, false, false
passed: true, true, true
test failed: 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_08415713922929102,
fake_7834476053041051,
fake_15257679729551743
result, different first party:
fake_19881872408639611,
fake_8334756599450519,
fake_6919572850147298
unsupported: false, false, false
passed: true, true, true
test failed: 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_2585936478091153,
fake_5386617428159388
result, different first party:
fake_32526985122306584,
fake_9929689797599532
unsupported: false, false
passed: true, true
test failed: 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 first party:
fake_891910587843846,
fake_7541618713874148,
fake_4231224474397046
result, different first party:
fake_891910587843846,
fake_7541618713874148,
fake_4231224474397046
unsupported: false, false, false
passed: false, false, false
test failed: 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_07333598895657345,
fake_1301042558465304,
fake_9983623540013735
result, different first party:
fake_538681439308365,
fake_913500313071653,
fake_8904744601123966
unsupported: false, false, false
passed: true, true, true
test failed: 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_34978056845212313,
fake_1024275498015248,
fake_5776727007995095
result, different first party:
fake_2811799825204173,
fake_6402965901773912,
fake_7322373944342717
unsupported: false, false, false
passed: true, true, true
test failed: 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_4449195265678292,
fake_36154859069303713,
fake_06346516205919861
result, different first party:
fake_8357717135993343,
fake_6934345821624301,
fake_8735076984693728
unsupported: false, false, false
passed: true, true, true
test failed: 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_31645228424221794,
fake_9130438601813033,
fake_9954610202747298
result, different first party:
fake_9251851704189402,
fake_5129956836982579,
fake_2484946263943899
unsupported: false, false, false
passed: true, true, true
test failed: 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_5404840072143149,
fake_9210208998390881,
fake_8796860756818621
result, different first party:
fake_8907494048179727,
fake_46303892408801484,
fake_8071753495342546
unsupported: false, false, false
passed: true, true, true
test failed: 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_6505289449729375,
fake_8383328563811632
result, different first party:
fake_7050479975439929,
fake_018699556183228605
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_041733584940245594,
fake_7994545577323866,
fake_12885141295656166
result, different first party:
fake_3057435936371269,
fake_7382976536147559,
fake_31046892557682604
unsupported: false, false, false
passed: true, true, true
test failed: 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_68279872888712,
fake_9485941873298387
result, different first party:
fake_9080093145329433,
fake_4951916856079648
unsupported: false, false
passed: true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 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 first party: 1, 1, 1
result, different first party: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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 first party: 1, 1, 1
result, different first party: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Unsupported
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:
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
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
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:
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
unsupported: true, true, true
passed: undefined
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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 first party: 1, 1
result, different first party: 1, 1
unsupported: false, false
passed: false, false
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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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 first party: 1, 1, 1
result, different first party: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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 first party: 1, 1, 1
result, different first party: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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:
9978c55e-bfb4-434b-b846-23d42090a687,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false
passed: true, true, true
test failed: 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:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1,
f2da4c27-b927-49c2-9e18-25f272c9328f,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false
passed: true, true, true
test failed: 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:
c7054ae3-6667-4a7e-a612-ca3225829997,
c98891bc-9d3d-40e1-963c-02a2e673d255
result, different first party:
Error: Unsupported,
Error: Unsupported
unsupported: false, false
passed: true, true
test failed: false, false
Failed
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:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
result, different first party:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
unsupported: false, false, false
passed: false, false, false
test failed: 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:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c,
715f3890-7ef6-4e6d-8c5e-f67837724eb4,
6df13641-2d34-4529-b349-3c5772849016
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false
passed: true, true, true
test failed: 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:
03ddb668-d164-434b-8703-85d4fc2e66dc,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: true, true, true
passed: undefined
test failed: 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:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5,
c2905ef6-4c9e-4027-8a34-105ee0be95a2,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false
passed: true, true, true
test failed: 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:
bef24721-ae28-44cf-b4e7-18ba6b47af22,
b752f8b5-1d43-4024-b85c-d0610aaad620,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false
passed: true, true, true
test failed: 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
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:
0f00b752-b58d-4191-84f3-6ca6518adaf2,
2233c25f-133b-4283-8605-f1b3293a7bd9,
42b37351-62ab-4493-8ca7-365d6a7f4847
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false
passed: true, true, true
test failed: 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:
2769613e-97f8-44a3-837f-189b84b9e278,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306
result, different first party:
Error: Unsupported,
Error: Unsupported
unsupported: false, false
passed: true, true
test failed: 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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
9978c55e-bfb4-434b-b846-23d42090a687,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1,
f2da4c27-b927-49c2-9e18-25f272c9328f,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
c7054ae3-6667-4a7e-a612-ca3225829997,
c98891bc-9d3d-40e1-963c-02a2e673d255
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
result, different first party:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c,
715f3890-7ef6-4e6d-8c5e-f67837724eb4,
6df13641-2d34-4529-b349-3c5772849016
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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:
03ddb668-d164-434b-8703-85d4fc2e66dc,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
cee0a24e-86b6-4713-865e-7c8c9dbc0330,
7e3c6442-4764-430e-ac99-8d3376daab80,
916da71a-153b-4626-878f-ff051279512b
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5,
c2905ef6-4c9e-4027-8a34-105ee0be95a2,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
bef24721-ae28-44cf-b4e7-18ba6b47af22,
b752f8b5-1d43-4024-b85c-d0610aaad620,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2
result, different first party:
bef24721-ae28-44cf-b4e7-18ba6b47af22,
b752f8b5-1d43-4024-b85c-d0610aaad620,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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:
c6728d83-23bd-4322-814e-ddcad72e88c4,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5
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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
0f00b752-b58d-4191-84f3-6ca6518adaf2,
2233c25f-133b-4283-8605-f1b3293a7bd9,
42b37351-62ab-4493-8ca7-365d6a7f4847
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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:
2769613e-97f8-44a3-837f-189b84b9e278,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: 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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
9978c55e-bfb4-434b-b846-23d42090a687,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1,
f2da4c27-b927-49c2-9e18-25f272c9328f,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
c7054ae3-6667-4a7e-a612-ca3225829997,
c98891bc-9d3d-40e1-963c-02a2e673d255
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
result, different first party:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c,
715f3890-7ef6-4e6d-8c5e-f67837724eb4,
6df13641-2d34-4529-b349-3c5772849016
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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:
03ddb668-d164-434b-8703-85d4fc2e66dc,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
cee0a24e-86b6-4713-865e-7c8c9dbc0330,
7e3c6442-4764-430e-ac99-8d3376daab80,
916da71a-153b-4626-878f-ff051279512b
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5,
c2905ef6-4c9e-4027-8a34-105ee0be95a2,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
bef24721-ae28-44cf-b4e7-18ba6b47af22,
b752f8b5-1d43-4024-b85c-d0610aaad620,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2
result, different first party:
bef24721-ae28-44cf-b4e7-18ba6b47af22,
b752f8b5-1d43-4024-b85c-d0610aaad620,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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:
c6728d83-23bd-4322-814e-ddcad72e88c4,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5
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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
0f00b752-b58d-4191-84f3-6ca6518adaf2,
2233c25f-133b-4283-8605-f1b3293a7bd9,
42b37351-62ab-4493-8ca7-365d6a7f4847
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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:
2769613e-97f8-44a3-837f-189b84b9e278,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: 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:
d442685efb9dcfaf1d7065b1b0a6ccba,
dbdb3f1c3741197daa6027e04c7c018e,
96f4d9c6d4025aa43534b86da3f14496
result, different first party:
d985500cb7f961e854e4b7a73814ff21,
302d9dacc2f0c3983d9a93ff7f1daab6,
349446b1408252b949d57f9096045ef8
unsupported: false, false, false
passed: true, true, true
test failed: 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:
ce86f69029c2021e367993859f12b898,
a16d9d498410114ff80e663d83e1224a,
eb7f4d6b9cf9a6a86c67f0da9259678a
result, different first party:
7180bc275c90a4971c80da57e06a5e84,
02a28cf39fae0265cec246c538159c6a,
4dbdc2fa0b0563e976d196a4b8d95c81
unsupported: false, false, false
passed: true, true, true
test failed: 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
passed: undefined
test failed: false, false
Failed
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:
140cb333bf49362a129c36da2bc27f54,
fff1d127ae8cabcd267bdbef71d6658c,
59149fd7bf2705fa2cb8d7596745df97
result, different first party:
140cb333bf49362a129c36da2bc27f54,
fff1d127ae8cabcd267bdbef71d6658c,
59149fd7bf2705fa2cb8d7596745df97
unsupported: false, false, false
passed: false, false, false
test failed: 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:
ca468b9b2ca95240d6bdb671d9ee77fd,
42d9cdefd4f70f47fce0fc88ad4d9a7a,
a88c3293322cb10189d2a1469da92169
result, different first party:
ebef753cfeb8d797cc854720739712c8,
0dce47561b4783efb1e473237b63513f,
0417ceb4b1cbed79aca8527278682bd8
unsupported: false, false, false
passed: true, true, true
test failed: 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:
c78f580b14595f974d2924ec8a8eeb6e,
0a500c49d6eea36dafbca85578b0880e,
96045c4dc41333798703f6d96eba97c2
result, different first party:
30fe8e542085057061f5ec7fe8d1a7a2,
22d5ffc8d0812b8900a0ee70cad6a0b1,
afe5c4f2ab342e385a521db62d2b9402
unsupported: false, false, false
passed: true, true, true
test failed: 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:
42f88f27b1b555d8f2acabc6c1e26ea8,
bfedfe5da9b43a021f2dd2b30c588557,
1ed3d55c64298dd002fe00651cd69a5a
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: 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:
70224ff0bda5cd3067e69404a3d76996,
566c44956550c8f002f7d3bb690114c3,
8abc7851bdad082ba09a06166d85ca25
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: 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
passed: undefined
test failed: 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
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:
2de488ab2599664ac27c17b65eadf27c,
24cbe0e71ca95c292a0c15a763638201,
a7720638177e232e03430b7e783b59ef
result, different first party:
3338c8d3779301f465129a1b065b3efc,
c7b7d33f36c4f66291b013d14144d9da,
b37ff0bab801b65e0752475c98ba269b
unsupported: false, false, false
passed: true, true, true
test failed: 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:
f23147cb0878e16e7736a05324e92126,
8085209e9299c29a924460143da7bf7f
result, different first party: , dd0a029497aa77e6d077b65dee6aa6d4
unsupported: false, false
passed: true, true
test failed: 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
result, different first party: Used http, Used http, Used http
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: 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
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
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested
result, different first party: Used http, Used http, Used http
unsupported: false, false, false
passed: true, true, true
test failed: 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
unsupported: , ,
passed: true, true, true
test failed: false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: 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
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
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https
unsupported: false, false
passed: false, false
test failed: 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
result, different first party: Used http, Used http, Used http
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: 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
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
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested
result, different first party: Used http, Used http, Used http
unsupported: false, false, false
passed: true, true, true
test failed: 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
unsupported: , ,
passed: true, true, true
test failed: false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: 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
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
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https
unsupported: false, false
passed: false, false
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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 first party: 1, 1, 1
result, different first party: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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 first party: 1, 1, 1
result, different first party: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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:
9978c55e-bfb4-434b-b846-23d42090a687,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc
result, different first party: undefined
unsupported: false, false, false
passed: true, true, true
test failed: 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:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1,
f2da4c27-b927-49c2-9e18-25f272c9328f,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc
result, different first party: undefined
unsupported: false, false, false
passed: true, true, true
test failed: 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:
c7054ae3-6667-4a7e-a612-ca3225829997,
c98891bc-9d3d-40e1-963c-02a2e673d255
result, different first party:
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same first party:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
result, different first party:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
unsupported: false, false, false
passed: false, false, false
test failed: 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:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c,
715f3890-7ef6-4e6d-8c5e-f67837724eb4,
6df13641-2d34-4529-b349-3c5772849016
result, different first party: undefined
unsupported: false, false, false
passed: true, true, true
test failed: 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:
03ddb668-d164-434b-8703-85d4fc2e66dc,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8
result, different first party: undefined
unsupported: false, false, false
passed: true, true, true
test failed: 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:
cee0a24e-86b6-4713-865e-7c8c9dbc0330,
7e3c6442-4764-430e-ac99-8d3376daab80,
916da71a-153b-4626-878f-ff051279512b
result, different first party: undefined
unsupported: false, false, false
passed: true, true, true
test failed: 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:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5,
c2905ef6-4c9e-4027-8a34-105ee0be95a2,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572
result, different first party: undefined
unsupported: false, false, false
passed: true, true, true
test failed: 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:
bef24721-ae28-44cf-b4e7-18ba6b47af22,
b752f8b5-1d43-4024-b85c-d0610aaad620,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2
result, different first party: undefined
unsupported: false, false, false
passed: true, true, true
test failed: 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:
c6728d83-23bd-4322-814e-ddcad72e88c4,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5
result, different first party:
Error: IDBFactory.open: The operation is insecure,
Error: IDBFactory.open: 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:
0f00b752-b58d-4191-84f3-6ca6518adaf2,
2233c25f-133b-4283-8605-f1b3293a7bd9,
42b37351-62ab-4493-8ca7-365d6a7f4847
result, different first party: undefined
unsupported: false, false, false
passed: true, true, true
test failed: 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:
2769613e-97f8-44a3-837f-189b84b9e278,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306
result, different first party: undefined
unsupported: false, false
passed: true, true
test failed: 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:
9978c55e-bfb4-434b-b846-23d42090a687,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1,
f2da4c27-b927-49c2-9e18-25f272c9328f,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
c7054ae3-6667-4a7e-a612-ca3225829997,
c98891bc-9d3d-40e1-963c-02a2e673d255
result, different first party:
Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.,
Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
result, different first party:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c,
715f3890-7ef6-4e6d-8c5e-f67837724eb4,
6df13641-2d34-4529-b349-3c5772849016
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
03ddb668-d164-434b-8703-85d4fc2e66dc,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
cee0a24e-86b6-4713-865e-7c8c9dbc0330,
7e3c6442-4764-430e-ac99-8d3376daab80,
916da71a-153b-4626-878f-ff051279512b
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5,
c2905ef6-4c9e-4027-8a34-105ee0be95a2,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
bef24721-ae28-44cf-b4e7-18ba6b47af22,
b752f8b5-1d43-4024-b85c-d0610aaad620,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
c6728d83-23bd-4322-814e-ddcad72e88c4,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5
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:
0f00b752-b58d-4191-84f3-6ca6518adaf2,
2233c25f-133b-4283-8605-f1b3293a7bd9,
42b37351-62ab-4493-8ca7-365d6a7f4847
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
2769613e-97f8-44a3-837f-189b84b9e278,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: 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:
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')
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')
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')
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')
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')
result, different first party:
Error: The request was denied.,
Error: The request was denied.
unsupported: false, false
passed: undefined
test failed: true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')
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')
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')
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')
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: queryResult.held[0] is undefined,
Error: queryResult.held[0] is undefined,
Error: queryResult.held[0] is undefined
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
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: queryResult.held[0] is undefined,
Error: queryResult.held[0] is undefined,
Error: queryResult.held[0] is undefined
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
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')
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')
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')
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')
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: queryResult.held[0] is undefined,
Error: queryResult.held[0] is undefined
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: undefined
test failed: true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')
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')
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')
result, different first party:
Error: Cannot read properties of undefined (reading 'name'),
Error: Cannot read properties of undefined (reading 'name')
unsupported: false, false
passed: undefined
test failed: true, true
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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same first party: 1, 1, 1
result, different first party: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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 first party: 1, 1, 1
result, different first party: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: , ,
result, different first party: , ,
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: , ,
result, different first party: , ,
unsupported: false, false, false
passed: undefined
test failed: true, true, true
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=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: ,
result, different first party:
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.,
Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.
unsupported: false, false
passed: undefined
test failed: true, true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: , ,
result, different first party: , ,
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: , ,
result, different first party: , ,
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: , ,
result, different first party: , ,
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Unsupported
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party:
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined
result, different first party:
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: , ,
result, different first party: , ,
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: , ,
result, different first party: , ,
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Unsupported
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party:
Error: navigator.serviceWorker is undefined,
Error: navigator.serviceWorker is undefined
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=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: , ,
result, different first party: , ,
unsupported: false, false, false
passed: undefined
test failed: true, true, true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: ,
result, different first party: ,
unsupported: false, false
passed: undefined
test failed: true, true
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.
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
result, different first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
result, different first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
result, different first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
unsupported: true, true
passed: undefined
test failed: false, false
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
result, different first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
result, different first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
result, different first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
result, different first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
unsupported: true, true, true
passed: undefined
test failed: 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:
Error: no SharedWorker message received,
Error: no SharedWorker message received
result, different first party:
Error: SharedWorker constructor: StorageAccess denied.,
Error: SharedWorker constructor: StorageAccess denied.
unsupported: false, false
passed: undefined
test failed: true, true
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
result, different first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
result, different first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
unsupported: true, true
passed: undefined
test failed: 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:
74f1deedc127395ef0dcff9bd8691907494170de25ae5b802b892e4d8d246bac,
5136bbb6ccec944d5fc6bc6c78d2dcf8b08c9294a1973d724e41c765dcfbb400,
12b9ce421df33a448e926fccf2b9ba93120b82bbf6603e1da2ac0e616f9b315b
result, different first party:
656053a7c44df3eb67a064ea31e01d2eb7eac1cd59ba4361b8fe95cb841e8dc6,
39f9d7a4d5d62bd05459c9528b1eb606704fb78b5cf72256f1935a7c8b3c2854,
1b8c09ef30abdbeec7e19fe22e9a419b7411b82dd3cf82f77894dda984068eb1
unsupported: false, false, false
passed: true, true, true
test failed: 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:
7798d55c96929b4fabc6d36805d91b83684c3a49595ba8449be2b95466cb1f64,
dea268fdc76cff166c9fb26f8c3482fef06c02ce3d3bfad63450c9604a437b10,
bbb3085ede4af18b1ac40a34d18dcb3992212d4ef8584fad7c89cb969ccdef6d
result, different first party:
a215824a1283de904db8bfc0af71ec7c62ba9eafba75f3c3f013e2cc7bd0028d,
296c1fb618e813e3249663f6a736461e35fba235c00456d87bb822b813b79385,
b740dd757e8cf721e72f4273d523be7d9fd1371eabe75c8f7b7c44168bbc866c
unsupported: false, false, false
passed: true, true, true
test failed: 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:
6059f96e5aafbf7dec483e2c3a316cc2715ddd5135c66def1bfe9f8f8ca30ffd,
c3803909cd1854eca33b8425f653b55198b3cc848a0bec0b73ff379f68a76da2
result, different first party:
97aa852821f25255b47a364dd22d95eb86398657a75ebde6ebc16ba38b83c4b7,
883deb36b2dae6700a4e91bfba6fd1d4420c1ca267777476a032eeebda5dbe12
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:
33593076fddfff3cd741a840611bdabf6c0e0c058a030fa4990e0fcc4cdf31c4,
edabf7ad23bcd897d3a4911e4c04cc8e8d902a5cb215db7fd0b9742ad9fd5561,
bd9649df15a70408d4e9b410077f8e91fcc6e94fb90b230898ddc165315c9468
result, different first party:
462f4068add63b72cbfd140f37b4fff74e4fb78d0851c0a44e51aaec9a7a5419,
acdf3d2cdd58aa4c310446fe9d9de80eb29609a8f7940e0cb27f7de9275c6096,
97579c263ae4941ea0379009dbba4c57ec0179256de4ac1125b56cf068d1ebe3
unsupported: false, false, false
passed: true, true, true
test failed: 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:
ce2572cd036432014039a3dc7727c68940c7ef94c83cad01300c0c9195f3215b,
a6ad3e128cd2d47ed34250c73a3c289efaec38554cecf930ad8d4fd90cc3c156,
1e96cb9e90444cf3ac9aa034b7eb73841fb258af786cb0b0c2523f42b5b94df5
result, different first party:
a7fd276ecb895465a21da5a052cc69011910625d12af44692c814d1768cf8255,
62d7414ca758257c4bf9e96623c1442390d2084b1ef594de4890a61ba12787ee,
af23a9110ed2f772241c41c769fbc725faf9234f446f7ea4b6658aafc050adf1
unsupported: false, false, false
passed: true, true, true
test failed: 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:
05178f71b039e12ce841b4a9233717b5675748ef622bc2e4b01817d7b98f7c43,
1d1132bcb63f7d6929f25c5db850c0d07e398f52d950a7e6e1119eac8b731ff7,
12cd185563135cd18c0fe8ab4b2e6ed97db4ecd8f6a6464b8e8ced742911a945
result, different first party:
4a0d4674426b128ef4d9601eaaf690f3a46d1cbf2274b0f7ecbbdb4faa630725,
9cbe0d8313ab77f52f859973c55fe96dec2e9488ba51ee77a28ee358df7e685c,
1660b594718ba58e3c5b80bf7b923e1e8703fcf8f07469ded15aef3f55a8f947
unsupported: false, false, false
passed: true, true, true
test failed: 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:
c4dfbe48905dec8da10c7f637369e0f6e165572b0dfb063276bd3a25010130b1,
b515588000c1bef6f3c680b501e36d95a38f1b264491da9f763bf60f0ab60056,
2a779ce20bf68a7a7d705d0204708cf2fa2b3859b398c6c4dbd1a44838735cac
result, different first party:
60a9b465cb807fa9933ecd0028854b8f2babe0d4b2d5362e3027099eefe61c75,
37b3daf3260ef552273f111939031dc0da4936c69b6d1192443244c46c540599,
7a5b5e407e138969be5f23aa7de9d3f8f5c42d62d422853a6ecb99041b5ba2df
unsupported: false, false, false
passed: true, true, true
test failed: 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:
276bcd745f7d20fa955c208db05ecf035be4bb87110263e81552d701a4fc147a,
14924f5786ff39c54c6c35abd23cbdf0e797a0f3201df9de62bb68a233925b0d,
9fa44dd1cefb9d05fe6d0d7522f394cf6abaac7aa11cf534157d9fc479182fcd
result, different first party:
f5e8016ed116920a2d18c86816a4e680801e02e9bd9db90a7406837401306030,
966a2c7b2cf4b668b08dbcf747770278770f9c81fa66c7ac3edfc7d9a061a736,
ee61d87af8b668b7cd020edd3d5776bbc91aa1d7b883ffff42ba231f312f879d
unsupported: false, false, false
passed: true, true, true
test failed: 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:
66496c370bab6005b041783b5a990b1a876b9826733e4e7d8dc79c5f4fed95fd,
ec70ba822c4ac841ad39715af83edbafbf5466277bbfbd7a1aa9f8f3103a1935,
325c01a4f41656eb2db931b1cf7b2be96d0528fb4d8e2091b15efa6dcf4f209b
result, different first party:
498469599162d931872acd0c1b20acf65ffc18682b2447e3f94d94882eef21ad,
b74b504a3775d3afdbe44e457ca09e11a7a82ce318b5cdc83f8636d388a2feeb,
8de205f6b381c6be2229d58454702e261b975b7390a4e70a87934bca4fd03292
unsupported: false, false, false
passed: true, true, true
test failed: 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:
18de93ea3bcc7ad5ec303524e3f630d3f7724c3ee00a45eed0b0ec4edae4fcb1,
20fb157a64b9dd3b12d3f9afa9c1279e53db3313746b84dca49c585b98924ff3
result, different first party:
92769eaf7c59d9a87d683ff0ad4e1edabe0dc19b1f0d0d02394aa15a1ed67948,
02d5860f1980a56eb7ecd36ecfffe1d5d5526735d723194a0c41635021dae39d
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:
243cf314deab0a7a96c553a04c21f42ae2b871c1a77b21665ba295c4cd41bbbe,
ab593257d41cb89525f94582c1be7940d5abf467a794d9a8084351fbaa28f4fc,
a7702de3a514cf176e453e9466ddaa5e6a8552a3fa15fb27aa4bdd2464fb2234
result, different first party:
2f1a08b84e367cb72dbc57a9b87000e9a55c0c687d5e215987405a60bef87b50,
51e69215f838553185b4c88e5f7525eadb95955b0b5e8a78fd09c371feb7f857,
a9821a9dc17330c94125cef9b077b23f23bd28e275011da8923c828b52978d44
unsupported: false, false, false
passed: true, true, true
test failed: 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:
3d13f1361edf24d56e5e35bf86e53d0d4188db3c8f27122f149c564445561c30,
81406d7f193cc40c2140fccb431206e4599b804ec4403a2764dad1f0b2ea2a9e
result, different first party:
57daacd315270fb21af68e6e25e2b7af8c98d69638c9855f01db18f69e537f35,
83a512ae628b4f13ffaef8c22cd19670cd55f56ea15e3ad14d0b25ea955e4c0c
unsupported: false, false
passed: true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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 first party: 1, 1, 1
result, different first party: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
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
result, different first party: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: 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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false
passed: false, false, false
test failed: 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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
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: ,
unsupported: false, false
passed: true, true
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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false
passed: false, false, false
test failed: 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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false
passed: false, false, false
test failed: 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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false
passed: false, false, false
test failed: 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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false
passed: false, false, false
test failed: 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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false
passed: false, false, false
test failed: 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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false
passed: false, false, false
test failed: 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/
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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false
passed: false, false, false
test failed: 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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false
passed: false, false
test failed: 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:
9978c55e-bfb4-434b-b846-23d42090a687,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1,
f2da4c27-b927-49c2-9e18-25f272c9328f,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
c7054ae3-6667-4a7e-a612-ca3225829997,
c98891bc-9d3d-40e1-963c-02a2e673d255
result, different first party:
Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document.,
Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document.
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
result, different first party:
a57cc61c-4dad-4d58-8993-b1599b60f30d,
aa5d30c0-0c9c-4088-ada9-3428936be9b2,
c3405b81-ce4e-47fb-9288-741b29aece7c
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c,
715f3890-7ef6-4e6d-8c5e-f67837724eb4,
6df13641-2d34-4529-b349-3c5772849016
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
03ddb668-d164-434b-8703-85d4fc2e66dc,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
cee0a24e-86b6-4713-865e-7c8c9dbc0330,
7e3c6442-4764-430e-ac99-8d3376daab80,
916da71a-153b-4626-878f-ff051279512b
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5,
c2905ef6-4c9e-4027-8a34-105ee0be95a2,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
bef24721-ae28-44cf-b4e7-18ba6b47af22,
b752f8b5-1d43-4024-b85c-d0610aaad620,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
c6728d83-23bd-4322-814e-ddcad72e88c4,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5
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:
0f00b752-b58d-4191-84f3-6ca6518adaf2,
2233c25f-133b-4283-8605-f1b3293a7bd9,
42b37351-62ab-4493-8ca7-365d6a7f4847
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
2769613e-97f8-44a3-837f-189b84b9e278,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: 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_9978c55e-bfb4-434b-b846-23d42090a687,
name_56a6d2e4-9823-4238-8e1f-a5a862efc2aa,
name_1f9112af-ba70-45ec-be2c-776fdc1d7dbc
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_d7ee9d12-7df5-4a82-b115-15b2e9f531d1,
name_f2da4c27-b927-49c2-9e18-25f272c9328f,
name_4de0e09a-506a-4647-a0a4-a42e98b7f5dc
result, different first party:
name_d7ee9d12-7df5-4a82-b115-15b2e9f531d1,
name_f2da4c27-b927-49c2-9e18-25f272c9328f,
name_4de0e09a-506a-4647-a0a4-a42e98b7f5dc
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_c7054ae3-6667-4a7e-a612-ca3225829997,
name_c98891bc-9d3d-40e1-963c-02a2e673d255
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_a57cc61c-4dad-4d58-8993-b1599b60f30d,
name_aa5d30c0-0c9c-4088-ada9-3428936be9b2,
name_c3405b81-ce4e-47fb-9288-741b29aece7c
result, different first party:
name_a57cc61c-4dad-4d58-8993-b1599b60f30d,
name_aa5d30c0-0c9c-4088-ada9-3428936be9b2,
name_c3405b81-ce4e-47fb-9288-741b29aece7c
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_4b6d1163-5e20-4f4b-909f-2e990ac4d13c,
name_715f3890-7ef6-4e6d-8c5e-f67837724eb4,
name_6df13641-2d34-4529-b349-3c5772849016
result, different first party:
name_4b6d1163-5e20-4f4b-909f-2e990ac4d13c,
name_715f3890-7ef6-4e6d-8c5e-f67837724eb4,
name_6df13641-2d34-4529-b349-3c5772849016
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_03ddb668-d164-434b-8703-85d4fc2e66dc,
name_1c00c1f6-a501-46c5-aeb4-476b0e14c57d,
name_69d2c505-d494-4fd1-b2c7-f0c5ad702fc8
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_cee0a24e-86b6-4713-865e-7c8c9dbc0330,
name_7e3c6442-4764-430e-ac99-8d3376daab80,
name_916da71a-153b-4626-878f-ff051279512b
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_c5490f42-7fe7-4bbe-81bf-ef30a44999a5,
name_c2905ef6-4c9e-4027-8a34-105ee0be95a2,
name_8c45d9ed-f12b-4b35-8bdd-b280be7b5572
result, different first party:
name_c5490f42-7fe7-4bbe-81bf-ef30a44999a5,
name_c2905ef6-4c9e-4027-8a34-105ee0be95a2,
name_8c45d9ed-f12b-4b35-8bdd-b280be7b5572
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_bef24721-ae28-44cf-b4e7-18ba6b47af22,
name_b752f8b5-1d43-4024-b85c-d0610aaad620,
name_3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2
result, different first party: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Passed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_c6728d83-23bd-4322-814e-ddcad72e88c4,
name_9eccf5e5-8b47-4f4f-bef1-589ec70f48b5
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_0f00b752-b58d-4191-84f3-6ca6518adaf2,
name_2233c25f-133b-4283-8605-f1b3293a7bd9,
name_42b37351-62ab-4493-8ca7-365d6a7f4847
result, different first party:
name_0f00b752-b58d-4191-84f3-6ca6518adaf2,
name_2233c25f-133b-4283-8605-f1b3293a7bd9,
name_42b37351-62ab-4493-8ca7-365d6a7f4847
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_2769613e-97f8-44a3-837f-189b84b9e278,
name_7bf7d308-02fa-44f1-8c73-ae9ae1e01306
result, different first party:
name_2769613e-97f8-44a3-837f-189b84b9e278,
name_7bf7d308-02fa-44f1-8c73-ae9ae1e01306
unsupported: false, false
passed: false, false
test failed: 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
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Passed
passed: true, true
result:
Insecure website never loaded,
Insecure website never loaded
Failed
passed: false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Passed
passed: true, true, true
result:
Insecure website never loaded,
Insecure website never loaded,
Insecure website never loaded
Failed
passed: false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Passed
passed: true, true
result:
Insecure website never loaded,
Insecure website never loaded
Failed
passed: false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false
result:
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
passed: true, true, true
Passed
upgraded: true, true, true
passed: true, true, true
Passed
upgraded: true, true
passed: true, true
Failed
upgraded: false, false, false
passed: false, false, false
Passed
upgraded: true, true, true
passed: true, true, true
Failed
upgraded: false, false, false
passed: false, false, false
Passed
upgraded: true, true, true
passed: true, true, true
Failed
upgraded: false, false, false
passed: false, false, false
Failed
upgraded: false, false, false
passed: false, false, false
Passed
upgraded: true, true
passed: true, true
Passed
upgraded: true, true, true
passed: true, true, true
Failed
upgraded: false, false
passed: false, false
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
passed: true, true, true
Passed
upgraded: true, true, true
passed: true, true, true
Passed
upgraded: true, true
passed: true, true
Failed
upgraded: false, false, false
passed: false, false, false
Passed
upgraded: true, true, true
passed: true, true, true
Failed
upgraded: false, false, false
passed: false, false, false
Passed
upgraded: true, true, true
passed: true, true, true
Failed
upgraded: false, false, false
passed: false, false, false
Passed
upgraded: true, true, true
passed: true, true, true
Passed
upgraded: true, true
passed: true, true
Passed
upgraded: true, true, true
passed: true, true, true
Failed
upgraded: true, false
passed: true, false
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
result: upgraded, upgraded, upgraded
Passed
passed: true, true, true
result: upgraded, upgraded, upgraded
Passed
passed: true, true
result: upgraded, upgraded
Failed
passed: false, false, false
result:
loaded insecurely,
loaded insecurely,
loaded insecurely
Passed
passed: true, true, true
result: upgraded, upgraded, upgraded
Passed
passed: true, true, true
result: upgraded, upgraded, upgraded
Passed
passed: true, true, true
result: upgraded, upgraded, upgraded
Passed
passed: true, true, true
result: upgraded, upgraded, upgraded
Passed
passed: true, true, true
result: upgraded, upgraded, upgraded
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true, true, true
result: upgraded, upgraded, upgraded
Passed
passed: true, true
result: 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
result: blocked, blocked, blocked
Passed
passed: true, true, true
result: blocked, blocked, blocked
Passed
passed: true, true
result: blocked, blocked
Passed
passed: true, true, true
result: blocked, blocked, blocked
Passed
passed: true, true, true
result: blocked, blocked, blocked
Passed
passed: true, true, true
result: blocked, blocked, blocked
Passed
passed: true, true, true
result: upgraded, upgraded, upgraded
Passed
passed: true, true, true
result: blocked, blocked, blocked
Passed
passed: true, true, true
result: blocked, blocked, blocked
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true, true, true
result: blocked, blocked, blocked
Passed
passed: true, true
result: 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
Passed
SNI_status: encrypted
passed: true, true, true
Failed
SNI_status: plaintext
passed: false, false
Failed
SNI_status: plaintext
passed: false, false, false
Failed
SNI_status: plaintext
passed: false, true, true
Failed
SNI_status: plaintext
passed: false, false, true
Failed
SNI_status: plaintext
passed: false, true, true
Failed
SNI_status: plaintext
passed: false, false, false
Failed
SNI_status: plaintext
passed: false, false, false
Failed
SNI_status: plaintext
passed: false, false
Passed
SNI_status: encrypted
passed: true, true, true
Passed
SNI_status: encrypted
passed: 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
Failed
header value: undefined
passed: false, false, false
Passed
header value: 1
passed: true, true
Passed
header value: 1
passed: true, true, true
Failed
header value: undefined
passed: false, false, false
Failed
header value: undefined
passed: false, false, false
Passed
header value: 1
passed: true, true, true
Failed
header value: undefined
passed: false, false, false
Failed
header value: undefined
passed: false, false, false
Passed
header value: 1
passed: true, true
Failed
header value: undefined
passed: false, false, false
Failed
header value: undefined
passed: 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
Failed
passed: false, false, false
Passed
sec-gpc: 1
passed: true, true
Failed
passed: false, false, false
Failed
passed: false, false, false
Failed
passed: false, false, false
Passed
sec-gpc: 1
passed: true, true, true
Failed
passed: false, false, false
Failed
passed: false, false, false
Passed
sec-gpc: 1
passed: true, true
Failed
passed: false, false, false
Failed
passed: 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
Failed
passed: false, false, false
Failed
passed: false, false
Failed
passed: false, false, false
Failed
passed: false, false, false
Failed
passed: false, false, false
Failed
passed: false, false, false
Failed
passed: false, false, false
Failed
passed: false, false, false
Passed
passed: true, true
Failed
passed: false, false, false
Failed
passed: 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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: 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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: 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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported
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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: 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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: 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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: 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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: 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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: 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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false
Passed
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: false, false
readSameFirstParty:
2001:67c:6ec:203:192:42:116:192,
2001:67c:6ec:203:192:42:116:210
readDifferentFirstParty:
195.47.238.89,
185.132.53.12
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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: 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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported
testFailed: 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
passed: false, false, false
Failed
IsTorExit: false, false, false
passed: false, false, false
Failed
IsTorExit: false, false
passed: false, false
Failed
IsTorExit: false, false, false
passed: false, false, false
Failed
IsTorExit: false, false, false
passed: false, false, false
Failed
IsTorExit: false, false, false
passed: false, false, false
Failed
IsTorExit: false, false, false
passed: false, false, false
Failed
IsTorExit: false, false, false
passed: false, false, false
Failed
IsTorExit: false, false, false
passed: false, false, false
Passed
IsTorExit: true, true
passed: true, true
Failed
IsTorExit: false, false, false
passed: false, false, false
Failed
IsTorExit: false, false
passed: 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.
Failed
expression: undefined
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 661,662
desired value: undefined
passed: false,false
Failed
expression: undefined
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: 1715,1715,1715
desired value: undefined
passed: true,true,true
Failed
expression: undefined
desired expression: undefined
actual value: undefined
desired value: undefined
passed: false,false
Failed
expression: undefined
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 800,800
desired value: undefined
passed: false,false
Media query screen width
Width of the user's screen in pixels.
Failed
expression: undefined
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 355,356
desired value: undefined
passed: false,false
Failed
expression: undefined
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Passed
expression: undefined
desired expression: undefined
actual value: 980,980,980
desired value: undefined
passed: true,true,true
Passed
expression: undefined
desired expression: undefined
actual value: 980,980
desired value: undefined
passed: true,true
Failed
expression: undefined
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: undefined
desired expression: undefined
actual value: 360,360
desired value: undefined
passed: false,false
outerHeight
Height of the browser window in pixels, including browser chrome.
Failed
expression: outerHeight
desired expression: undefined
actual value: 916,916,916
desired value: undefined
passed: false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 670,670,670
desired value: undefined
passed: false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 661,662
desired value: undefined
passed: false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 670,670,670
desired value: undefined
passed: false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 622,622,622
desired value: undefined
passed: false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 725,725,725
desired value: undefined
passed: false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 725,725,725
desired value: undefined
passed: false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 614,614,614
desired value: undefined
passed: false,false,false
Passed
expression: outerHeight
desired expression: undefined
actual value: 1715,1715,1715
desired value: undefined
passed: true,true,true
Passed
expression: outerHeight
desired expression: undefined
actual value: 1822,1822
desired value: undefined
passed: true,true
Failed
expression: outerHeight
desired expression: undefined
actual value: 582,582,582
desired value: undefined
passed: false,false,false
Failed
expression: outerHeight
desired expression: undefined
actual value: 618,618
desired value: undefined
passed: false,false
screen.height
Height of the user's screen, in pixels.
Failed
expression: screen.height
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 661,662
desired value: undefined
passed: false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Passed
expression: screen.height
desired expression: undefined
actual value: 1715,1715,1715
desired value: undefined
passed: true,true,true
Passed
expression: screen.height
desired expression: undefined
actual value: 1822,1822
desired value: undefined
passed: true,true
Failed
expression: screen.height
desired expression: undefined
actual value: 800,800,800
desired value: undefined
passed: false,false,false
Failed
expression: screen.height
desired expression: undefined
actual value: 800,800
desired value: undefined
passed: false,false
screen.width
Width of the user's screen, in pixels.
Failed
expression: screen.width
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 355,356
desired value: undefined
passed: false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Passed
expression: screen.width
desired expression: undefined
actual value: 980,980,980
desired value: undefined
passed: true,true,true
Passed
expression: screen.width
desired expression: undefined
actual value: 980,980
desired value: undefined
passed: true,true
Failed
expression: screen.width
desired expression: undefined
actual value: 360,360,360
desired value: undefined
passed: false,false,false
Failed
expression: screen.width
desired expression: undefined
actual value: 360,360
desired value: undefined
passed: false,false
screenX
Position, in pixels, of the left edge of the browser window on screen.
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0
desired value: undefined
passed: true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0
desired value: undefined
passed: true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenX
desired expression: undefined
actual value: 0,0
desired value: undefined
passed: true,true
screenY
Position, in pixels, of the top edge of the browser window on screen.
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0
desired value: undefined
passed: true,true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Failed
expression: screenY
desired expression: undefined
actual value: 83,83,83
desired value: undefined
passed: false,false,false
Failed
expression: screenY
desired expression: undefined
actual value: 83,83,83
desired value: undefined
passed: false,false,false
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0
desired value: undefined
passed: true,true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0,0
desired value: undefined
passed: true,true,true
Passed
expression: screenY
desired expression: undefined
actual value: 0,0
desired value: undefined
passed: true,true
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
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
__hssc
HubSpot tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
__hstc
HubSpot tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
__s
Drip.com email address tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
_hsenc
HubSpot tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
_openstat
Yandex tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
dclid
DoubleClick Click ID (Google)
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
fbclid
Facebook Click Identifier
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
gclid
Google Click Identifier
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
hsCtaTracking
HubSpot tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
mc_eid
Mailchimp Email ID (email recipient's address)
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
mkt_tok
Adobe Marketo tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
ml_subscriber
MailerLite email tracking
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
ml_subscriber_hash
MailerLite email tracking
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
msclkid
Microsoft Click ID
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
oly_anon_id
Omeda marketing 'anonymous' customer id
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
oly_enc_id
Omeda marketing 'known' customer id
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
rb_clickid
Unknown high-entropy tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
s_cid
Adobe Site Catalyst tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
vero_conv
Vero tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
vero_id
Vero tracking parameter
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
wickedid
Wicked Reports e-commerce tracking
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
yclid
Yandex Click ID
Passed
passed: true, true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: false, false, false
Passed
passed: true, true
Failed
value: 6398485611208986
passed: false, false, false
Failed
value: 6398485611208986
passed: 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
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true, true, true
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true, true, true
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: 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
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false
Passed
url: https://dpm.demdex.net/ibs
passed: true, true, true
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false
Passed
url: https://dpm.demdex.net/ibs
passed: true, true, true
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false
Failed
url: https://dpm.demdex.net/ibs
passed: 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
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true, true
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true, true
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true, true
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: 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
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true, true
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true, true
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true, true
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, 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
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: 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
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false
Passed
url: https://bat.bing.com/bat.js
passed: true, true, true
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false
Passed
url: https://bat.bing.com/bat.js
passed: true, true, true
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false
Chartbeat
Tests whether the browser blocks the page from loading the tracker at https://static.chartbeat.com/js/chartbeat.js
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true, true, true
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true, true, true
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true, true, true
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, 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
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: 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
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true, true
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true, true
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, 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
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: 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
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false, false, false
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true, true
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false, false, false
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false, false, false
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true, true
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true, true
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false, false, 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
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: 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
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true, true
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true, true
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, 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
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: 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
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false, false
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true, true
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true, true, true
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false, false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false, false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false, false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false, false
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false, 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
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: 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
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false
Passed
url: https://google-analytics.com/urchin.js
passed: true, true, true
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false
Passed
url: https://google-analytics.com/urchin.js
passed: true, true, true
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false
Failed
url: https://google-analytics.com/urchin.js
passed: 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
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true, true, true
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, 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
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: 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
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false, false, false
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true, true
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: 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
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: 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
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: 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
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
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: 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
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true, true
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true, true
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, 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
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: 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
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false
Passed
url: https://pixel.quantserve.com/pixel
passed: true, true, true
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false
Passed
url: https://pixel.quantserve.com/pixel
passed: true, true, true
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: 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
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false, false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true, true
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false, false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false, false
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true, true
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false, false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false, 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
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: 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
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true, true, true
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true, true, true
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, 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
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: 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
Failed
url: https://t.co/i/adsct
passed: false, false, false
Passed
url: https://t.co/i/adsct
passed: true, true
Passed
url: https://t.co/i/adsct
passed: true, true, true
Failed
url: https://t.co/i/adsct
passed: false, false, false
Failed
url: https://t.co/i/adsct
passed: false, false, false
Passed
url: https://t.co/i/adsct
passed: true, true, true
Failed
url: https://t.co/i/adsct
passed: false, false, false
Failed
url: https://t.co/i/adsct
passed: false, false, false
Failed
url: https://t.co/i/adsct
passed: false, false
Failed
url: https://t.co/i/adsct
passed: false, false, false
Failed
url: https://t.co/i/adsct
passed: 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
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true, true
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true, true, true
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true, true, true
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, 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
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: 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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
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
result, different session: h3, h2, h3
unsupported: false, false, false
passed: false, true, false
test failed: 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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different session: h2, h2, h2
unsupported: true, true, true
passed: undefined
test failed: 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
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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different session: h2, h2
unsupported: false, false
passed: true, true
test failed: 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.
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
143d61f8-2894-4529-ad80-0a53e9ebc6cc_1p,
143d61f8-2894-4529-ad80-0a53e9ebc6cc_1p,
143d61f8-2894-4529-ad80-0a53e9ebc6cc_1p
result, different session:
143d61f8-2894-4529-ad80-0a53e9ebc6cc_1p,
143d61f8-2894-4529-ad80-0a53e9ebc6cc_1p,
143d61f8-2894-4529-ad80-0a53e9ebc6cc_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
c745bf91-cf98-4e5f-8375-d1de83cf19d5_1p,
c745bf91-cf98-4e5f-8375-d1de83cf19d5_1p,
c745bf91-cf98-4e5f-8375-d1de83cf19d5_1p
result, different session:
c745bf91-cf98-4e5f-8375-d1de83cf19d5_1p,
c745bf91-cf98-4e5f-8375-d1de83cf19d5_1p,
c745bf91-cf98-4e5f-8375-d1de83cf19d5_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
c7054ae3-6667-4a7e-a612-ca3225829997_1p,
c7054ae3-6667-4a7e-a612-ca3225829997_1p
result, different session:
c7054ae3-6667-4a7e-a612-ca3225829997_1p,
c7054ae3-6667-4a7e-a612-ca3225829997_1p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
15571fa3-0642-4589-90a9-ec73a7a073d9_1p,
15571fa3-0642-4589-90a9-ec73a7a073d9_1p,
15571fa3-0642-4589-90a9-ec73a7a073d9_1p
result, different session:
15571fa3-0642-4589-90a9-ec73a7a073d9_1p,
15571fa3-0642-4589-90a9-ec73a7a073d9_1p,
15571fa3-0642-4589-90a9-ec73a7a073d9_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_1p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_1p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_1p
result, different session:
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_1p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_1p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
6b80d03e-105e-4201-b76d-0596f346aaac_1p,
6b80d03e-105e-4201-b76d-0596f346aaac_1p,
6b80d03e-105e-4201-b76d-0596f346aaac_1p
result, different session:
6b80d03e-105e-4201-b76d-0596f346aaac_1p,
6b80d03e-105e-4201-b76d-0596f346aaac_1p,
6b80d03e-105e-4201-b76d-0596f346aaac_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_1p,
7e3c6442-4764-430e-ac99-8d3376daab80_1p,
916da71a-153b-4626-878f-ff051279512b_1p
result, different session:
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
c97b5d06-2396-4bb1-9f7d-6fde65072b04_1p,
c97b5d06-2396-4bb1-9f7d-6fde65072b04_1p,
c97b5d06-2396-4bb1-9f7d-6fde65072b04_1p
result, different session:
c97b5d06-2396-4bb1-9f7d-6fde65072b04_1p,
c97b5d06-2396-4bb1-9f7d-6fde65072b04_1p,
c97b5d06-2396-4bb1-9f7d-6fde65072b04_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
a31f089a-366d-46aa-8a3d-39c59eae3ef3_1p,
a31f089a-366d-46aa-8a3d-39c59eae3ef3_1p,
a31f089a-366d-46aa-8a3d-39c59eae3ef3_1p
result, different session:
a31f089a-366d-46aa-8a3d-39c59eae3ef3_1p,
a31f089a-366d-46aa-8a3d-39c59eae3ef3_1p,
a31f089a-366d-46aa-8a3d-39c59eae3ef3_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
c6728d83-23bd-4322-814e-ddcad72e88c4_1p,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5_1p
result, different session:
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
1af58a1e-55c5-4125-ba6b-5729d21fd23c_1p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_1p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_1p
result, different session:
1af58a1e-55c5-4125-ba6b-5729d21fd23c_1p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_1p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
2769613e-97f8-44a3-837f-189b84b9e278_1p,
2769613e-97f8-44a3-837f-189b84b9e278_1p
result, different session:
2769613e-97f8-44a3-837f-189b84b9e278_1p,
2769613e-97f8-44a3-837f-189b84b9e278_1p
unsupported: false, false
passed: false, false
test failed: 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.
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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
9978c55e-bfb4-434b-b846-23d42090a687_1p_http,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_1p_http,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_1p_http
result, different session:
9978c55e-bfb4-434b-b846-23d42090a687_1p_http,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_1p_http,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_1p_http
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_1p_http,
f2da4c27-b927-49c2-9e18-25f272c9328f_1p_http,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_1p_http
result, different session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_1p_http,
f2da4c27-b927-49c2-9e18-25f272c9328f_1p_http,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_1p_http
unsupported: false, false, false
passed: false, false, false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
c7054ae3-6667-4a7e-a612-ca3225829997_1p_http,
c98891bc-9d3d-40e1-963c-02a2e673d255_1p_http
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
a57cc61c-4dad-4d58-8993-b1599b60f30d_1p_http,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_1p_http,
c3405b81-ce4e-47fb-9288-741b29aece7c_1p_http
result, different session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_1p_http,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_1p_http,
c3405b81-ce4e-47fb-9288-741b29aece7c_1p_http
unsupported: false, false, false
passed: false, false, false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_1p_http,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_1p_http,
6df13641-2d34-4529-b349-3c5772849016_1p_http
result, different session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_1p_http,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_1p_http,
6df13641-2d34-4529-b349-3c5772849016_1p_http
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
03ddb668-d164-434b-8703-85d4fc2e66dc_1p_http,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_1p_http,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_1p_http
result, different session:
03ddb668-d164-434b-8703-85d4fc2e66dc_1p_http,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_1p_http,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_1p_http
unsupported: false, false, false
passed: false, false, false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_1p_http,
7e3c6442-4764-430e-ac99-8d3376daab80_1p_http,
916da71a-153b-4626-878f-ff051279512b_1p_http
result, different session: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_1p_http,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_1p_http,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_1p_http
result, different session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_1p_http,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_1p_http,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_1p_http
unsupported: false, false, false
passed: false, false, false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_1p_http,
b752f8b5-1d43-4024-b85c-d0610aaad620_1p_http,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_1p_http
result, different session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_1p_http,
b752f8b5-1d43-4024-b85c-d0610aaad620_1p_http,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_1p_http
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
c6728d83-23bd-4322-814e-ddcad72e88c4_1p_http,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5_1p_http
result, different session: ,
unsupported: false, false
passed: true, true
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_1p_http,
2233c25f-133b-4283-8605-f1b3293a7bd9_1p_http,
42b37351-62ab-4493-8ca7-365d6a7f4847_1p_http
result, different session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_1p_http,
2233c25f-133b-4283-8605-f1b3293a7bd9_1p_http,
42b37351-62ab-4493-8ca7-365d6a7f4847_1p_http
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
2769613e-97f8-44a3-837f-189b84b9e278_1p_http,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_1p_http
result, different session:
2769613e-97f8-44a3-837f-189b84b9e278_1p_http,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_1p_http
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
9978c55e-bfb4-434b-b846-23d42090a687_1p_js,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_1p_js,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_1p_js
result, different session:
9978c55e-bfb4-434b-b846-23d42090a687_1p_js,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_1p_js,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_1p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_1p_js,
f2da4c27-b927-49c2-9e18-25f272c9328f_1p_js,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_1p_js
result, different session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_1p_js,
f2da4c27-b927-49c2-9e18-25f272c9328f_1p_js,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_1p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
c7054ae3-6667-4a7e-a612-ca3225829997_1p_js,
c98891bc-9d3d-40e1-963c-02a2e673d255_1p_js
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_1p_js,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_1p_js,
c3405b81-ce4e-47fb-9288-741b29aece7c_1p_js
result, different session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_1p_js,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_1p_js,
c3405b81-ce4e-47fb-9288-741b29aece7c_1p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_1p_js,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_1p_js,
6df13641-2d34-4529-b349-3c5772849016_1p_js
result, different session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_1p_js,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_1p_js,
6df13641-2d34-4529-b349-3c5772849016_1p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
03ddb668-d164-434b-8703-85d4fc2e66dc_1p_js,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_1p_js,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_1p_js
result, different session:
03ddb668-d164-434b-8703-85d4fc2e66dc_1p_js,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_1p_js,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_1p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_1p_js,
7e3c6442-4764-430e-ac99-8d3376daab80_1p_js,
916da71a-153b-4626-878f-ff051279512b_1p_js
result, different session: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_1p_js,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_1p_js,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_1p_js
result, different session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_1p_js,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_1p_js,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_1p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_1p_js,
b752f8b5-1d43-4024-b85c-d0610aaad620_1p_js,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_1p_js
result, different session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_1p_js,
b752f8b5-1d43-4024-b85c-d0610aaad620_1p_js,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_1p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
c6728d83-23bd-4322-814e-ddcad72e88c4_1p_js,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5_1p_js
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_1p_js,
2233c25f-133b-4283-8605-f1b3293a7bd9_1p_js,
42b37351-62ab-4493-8ca7-365d6a7f4847_1p_js
result, different session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_1p_js,
2233c25f-133b-4283-8605-f1b3293a7bd9_1p_js,
42b37351-62ab-4493-8ca7-365d6a7f4847_1p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
2769613e-97f8-44a3-837f-189b84b9e278_1p_js,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_1p_js
result, different session:
2769613e-97f8-44a3-837f-189b84b9e278_1p_js,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_1p_js
unsupported: false, false
passed: false, false
test failed: false, false
CookieStore
The Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.
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 session:
9978c55e-bfb4-434b-b846-23d42090a687_1p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_1p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_1p
result, different session:
9978c55e-bfb4-434b-b846-23d42090a687_1p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_1p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_1p
unsupported: false, false, false
passed: false, false, false
test failed: 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 session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_1p,
f2da4c27-b927-49c2-9e18-25f272c9328f_1p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_1p
result, different session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_1p,
f2da4c27-b927-49c2-9e18-25f272c9328f_1p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_1p
unsupported: false, false, false
passed: false, false, false
test failed: 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:
c7054ae3-6667-4a7e-a612-ca3225829997_1p,
c98891bc-9d3d-40e1-963c-02a2e673d255_1p
result, different session: ,
unsupported: false, false
passed: true, true
test failed: 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 session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_1p,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_1p,
c3405b81-ce4e-47fb-9288-741b29aece7c_1p
result, different session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_1p,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_1p,
c3405b81-ce4e-47fb-9288-741b29aece7c_1p
unsupported: false, false, false
passed: false, false, false
test failed: 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 session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_1p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_1p,
6df13641-2d34-4529-b349-3c5772849016_1p
result, different session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_1p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_1p,
6df13641-2d34-4529-b349-3c5772849016_1p
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: true, true, true
passed: undefined
test failed: 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
result, different session:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: true, true, true
passed: undefined
test failed: 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 session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_1p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_1p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_1p
result, different session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_1p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_1p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_1p
unsupported: false, false, false
passed: false, false, false
test failed: 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 session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_1p,
b752f8b5-1d43-4024-b85c-d0610aaad620_1p,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_1p
result, different session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_1p,
b752f8b5-1d43-4024-b85c-d0610aaad620_1p,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_1p
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session:
Error: Unsupported,
Error: Unsupported
unsupported: true, true
passed: undefined
test failed: 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 session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_1p,
2233c25f-133b-4283-8605-f1b3293a7bd9_1p,
42b37351-62ab-4493-8ca7-365d6a7f4847_1p
result, different session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_1p,
2233c25f-133b-4283-8605-f1b3293a7bd9_1p,
42b37351-62ab-4493-8ca7-365d6a7f4847_1p
unsupported: false, false, false
passed: false, false, false
test failed: 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 session:
2769613e-97f8-44a3-837f-189b84b9e278_1p,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_1p
result, different session:
2769613e-97f8-44a3-837f-189b84b9e278_1p,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_1p
unsupported: false, false
passed: false, false
test failed: 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.
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_569238780501222,
fake_17072572442348877,
fake_5503817118297865
result, different session:
fake_569238780501222,
fake_17072572442348877,
fake_5503817118297865
unsupported: false, false, false
passed: false, false, false
test failed: 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_43222439005919777,
fake_92502649145961,
fake_986392264168843
result, different session:
fake_43222439005919777,
fake_92502649145961,
fake_986392264168843
unsupported: false, false, false
passed: false, false, false
test failed: 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_21352710122680985,
fake_9407930093020727
result, different session:
fake_21352710122680985,
fake_9407930093020727
unsupported: false, false
passed: false, false
test failed: 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_3022987121559737,
fake_7866906404744494,
fake_12837563053105416
result, different session:
fake_3022987121559737,
fake_7866906404744494,
fake_12837563053105416
unsupported: false, false, false
passed: false, false, false
test failed: 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_6996912814794891,
fake_7513197593876888,
fake_19701344828879974
result, different session:
fake_6996912814794891,
fake_7513197593876888,
fake_19701344828879974
unsupported: false, false, false
passed: false, false, false
test failed: 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_722345791285621,
fake_6272616737513894,
fake_3733160688705879
result, different session:
fake_722345791285621,
fake_6272616737513894,
fake_3733160688705879
unsupported: false, false, false
passed: false, false, false
test failed: 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_13863915606242783,
fake_23464477191778021,
fake_7032250049301743
result, different session:
fake_2402514084555758,
fake_05927253090936646,
fake_39642715152290453
unsupported: false, false, false
passed: true, true, true
test failed: 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_008942488988772368,
fake_5704566911550613,
fake_7637929956841034
result, different session:
fake_008942488988772368,
fake_5704566911550613,
fake_7637929956841034
unsupported: false, false, false
passed: false, false, false
test failed: 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_980877134197532,
fake_5961353536478387,
fake_7173111411265574
result, different session:
fake_980877134197532,
fake_5961353536478387,
fake_7173111411265574
unsupported: false, false, false
passed: false, false, false
test failed: 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_018753568477895666,
fake_01343339921813791
result, different session:
fake_7435398875344812,
fake_9275704697325244
unsupported: false, false
passed: true, true
test failed: 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_38761964873432997,
fake_9212432966514197,
fake_4507714366656337
result, different session:
fake_38761964873432997,
fake_9212432966514197,
fake_4507714366656337
unsupported: false, false, false
passed: false, false, false
test failed: 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_4591096248087603,
fake_3882485990149176
result, different session:
fake_4591096248087603,
fake_3882485990149176
unsupported: false, false
passed: false, false
test failed: 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.
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
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
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
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Unsupported
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:
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
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
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:
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
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
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
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
font cache
Web fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
9978c55e-bfb4-434b-b846-23d42090a687_1p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_1p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_1p
result, different session:
9978c55e-bfb4-434b-b846-23d42090a687_1p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_1p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_1p,
f2da4c27-b927-49c2-9e18-25f272c9328f_1p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_1p
result, different session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_1p,
f2da4c27-b927-49c2-9e18-25f272c9328f_1p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
c7054ae3-6667-4a7e-a612-ca3225829997_1p,
c98891bc-9d3d-40e1-963c-02a2e673d255_1p
result, different session:
c7054ae3-6667-4a7e-a612-ca3225829997_1p,
c98891bc-9d3d-40e1-963c-02a2e673d255_1p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_1p,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_1p,
c3405b81-ce4e-47fb-9288-741b29aece7c_1p
result, different session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_1p,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_1p,
c3405b81-ce4e-47fb-9288-741b29aece7c_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_1p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_1p,
6df13641-2d34-4529-b349-3c5772849016_1p
result, different session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_1p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_1p,
6df13641-2d34-4529-b349-3c5772849016_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
03ddb668-d164-434b-8703-85d4fc2e66dc_1p,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_1p,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_1p
result, different session:
03ddb668-d164-434b-8703-85d4fc2e66dc_1p,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_1p,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_1p
unsupported: false, false, false
passed: false, false, false
test failed: 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:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_1p,
7e3c6442-4764-430e-ac99-8d3376daab80_1p,
916da71a-153b-4626-878f-ff051279512b_1p
result, different session: undefined
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_1p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_1p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_1p
result, different session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_1p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_1p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_1p,
b752f8b5-1d43-4024-b85c-d0610aaad620_1p,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_1p
result, different session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_1p,
b752f8b5-1d43-4024-b85c-d0610aaad620_1p,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_1p
unsupported: false, false, false
passed: false, false, false
test failed: 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:
c6728d83-23bd-4322-814e-ddcad72e88c4_1p,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5_1p
result, different session: undefined
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_1p,
2233c25f-133b-4283-8605-f1b3293a7bd9_1p,
42b37351-62ab-4493-8ca7-365d6a7f4847_1p
result, different session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_1p,
2233c25f-133b-4283-8605-f1b3293a7bd9_1p,
42b37351-62ab-4493-8ca7-365d6a7f4847_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
2769613e-97f8-44a3-837f-189b84b9e278_1p,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_1p
result, different session:
2769613e-97f8-44a3-837f-189b84b9e278_1p,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_1p
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
9978c55e-bfb4-434b-b846-23d42090a687_1p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_1p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_1p
result, different session:
9978c55e-bfb4-434b-b846-23d42090a687_1p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_1p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_1p,
f2da4c27-b927-49c2-9e18-25f272c9328f_1p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_1p
result, different session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_1p,
f2da4c27-b927-49c2-9e18-25f272c9328f_1p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
c7054ae3-6667-4a7e-a612-ca3225829997_1p,
c98891bc-9d3d-40e1-963c-02a2e673d255_1p
result, different session:
c7054ae3-6667-4a7e-a612-ca3225829997_1p,
c98891bc-9d3d-40e1-963c-02a2e673d255_1p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_1p,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_1p,
c3405b81-ce4e-47fb-9288-741b29aece7c_1p
result, different session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_1p,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_1p,
c3405b81-ce4e-47fb-9288-741b29aece7c_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_1p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_1p,
6df13641-2d34-4529-b349-3c5772849016_1p
result, different session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_1p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_1p,
6df13641-2d34-4529-b349-3c5772849016_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
03ddb668-d164-434b-8703-85d4fc2e66dc_1p,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_1p,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_1p
result, different session:
03ddb668-d164-434b-8703-85d4fc2e66dc_1p,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_1p,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_1p,
7e3c6442-4764-430e-ac99-8d3376daab80_1p,
916da71a-153b-4626-878f-ff051279512b_1p
result, different session: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_1p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_1p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_1p
result, different session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_1p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_1p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_1p,
b752f8b5-1d43-4024-b85c-d0610aaad620_1p,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_1p
result, different session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_1p,
b752f8b5-1d43-4024-b85c-d0610aaad620_1p,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
c6728d83-23bd-4322-814e-ddcad72e88c4_1p,
9eccf5e5-8b47-4f4f-bef1-589ec70f48b5_1p
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_1p,
2233c25f-133b-4283-8605-f1b3293a7bd9_1p,
42b37351-62ab-4493-8ca7-365d6a7f4847_1p
result, different session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_1p,
2233c25f-133b-4283-8605-f1b3293a7bd9_1p,
42b37351-62ab-4493-8ca7-365d6a7f4847_1p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
2769613e-97f8-44a3-837f-189b84b9e278_1p,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_1p
result, different session:
2769613e-97f8-44a3-837f-189b84b9e278_1p,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_1p
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session:
Error: No requests received,
Error: No requests received
unsupported: true, true
passed: undefined
test failed: false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
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
result, different session: h3, h2, h3
unsupported: false, false, false
passed: false, true, false
test failed: 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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different session: h2, h2, h2
unsupported: true, true, true
passed: undefined
test failed: 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
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
result, different session: h2, h2, h2
unsupported: false, false, false
passed: true, true, true
test failed: 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
result, different session: h2, h2
unsupported: false, false
passed: true, true
test failed: 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.
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
9978c55e-bfb4-434b-b846-23d42090a687_3p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_3p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_3p
result, different session:
9978c55e-bfb4-434b-b846-23d42090a687_3p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_3p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
c745bf91-cf98-4e5f-8375-d1de83cf19d5_3p,
c745bf91-cf98-4e5f-8375-d1de83cf19d5_3p,
c745bf91-cf98-4e5f-8375-d1de83cf19d5_3p
result, different session:
c745bf91-cf98-4e5f-8375-d1de83cf19d5_3p,
c745bf91-cf98-4e5f-8375-d1de83cf19d5_3p,
c745bf91-cf98-4e5f-8375-d1de83cf19d5_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.
result, different session:
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.,
Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.
unsupported: true, true
passed: undefined
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p,
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p,
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p
result, different session:
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p,
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p,
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_3p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_3p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_3p
result, different session:
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_3p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_3p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
6b80d03e-105e-4201-b76d-0596f346aaac_3p,
6b80d03e-105e-4201-b76d-0596f346aaac_3p,
6b80d03e-105e-4201-b76d-0596f346aaac_3p
result, different session:
6b80d03e-105e-4201-b76d-0596f346aaac_3p,
6b80d03e-105e-4201-b76d-0596f346aaac_3p,
6b80d03e-105e-4201-b76d-0596f346aaac_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_3p,
7e3c6442-4764-430e-ac99-8d3376daab80_3p,
916da71a-153b-4626-878f-ff051279512b_3p
result, different session:
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined,
Error: cacheKeys[0] is undefined
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
1a184507-9b7a-45eb-a7c2-93b91227080c_3p,
1a184507-9b7a-45eb-a7c2-93b91227080c_3p,
1a184507-9b7a-45eb-a7c2-93b91227080c_3p
result, different session:
1a184507-9b7a-45eb-a7c2-93b91227080c_3p,
1a184507-9b7a-45eb-a7c2-93b91227080c_3p,
1a184507-9b7a-45eb-a7c2-93b91227080c_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
62cb741f-c8c7-452b-a081-453be7d8a485_3p,
62cb741f-c8c7-452b-a081-453be7d8a485_3p,
62cb741f-c8c7-452b-a081-453be7d8a485_3p
result, different session:
62cb741f-c8c7-452b-a081-453be7d8a485_3p,
62cb741f-c8c7-452b-a081-453be7d8a485_3p,
62cb741f-c8c7-452b-a081-453be7d8a485_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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.
result, different session:
Error: The operation is insecure.,
Error: The operation is insecure.
unsupported: true, true
passed: undefined
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
1af58a1e-55c5-4125-ba6b-5729d21fd23c_3p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_3p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_3p
result, different session:
1af58a1e-55c5-4125-ba6b-5729d21fd23c_3p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_3p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
2769613e-97f8-44a3-837f-189b84b9e278_3p,
2769613e-97f8-44a3-837f-189b84b9e278_3p
result, different session:
2769613e-97f8-44a3-837f-189b84b9e278_3p,
2769613e-97f8-44a3-837f-189b84b9e278_3p
unsupported: false, false
passed: false, false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
9978c55e-bfb4-434b-b846-23d42090a687_3p_http,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_3p_http,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_3p_http
result, different session: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_3p_http,
f2da4c27-b927-49c2-9e18-25f272c9328f_3p_http,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_3p_http
result, different session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_3p_http,
f2da4c27-b927-49c2-9e18-25f272c9328f_3p_http,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_3p_http
unsupported: false, false, false
passed: false, false, false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session: ,
result, different session: ,
unsupported: true, true
passed: undefined
test failed: false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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
passed: undefined
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_3p_http,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_3p_http,
6df13641-2d34-4529-b349-3c5772849016_3p_http
result, different session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_3p_http,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_3p_http,
6df13641-2d34-4529-b349-3c5772849016_3p_http
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
03ddb668-d164-434b-8703-85d4fc2e66dc_3p_http,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_3p_http,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_3p_http
result, different session:
03ddb668-d164-434b-8703-85d4fc2e66dc_3p_http,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_3p_http,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_3p_http
unsupported: false, false, false
passed: false, false, false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_3p_http,
7e3c6442-4764-430e-ac99-8d3376daab80_3p_http,
916da71a-153b-4626-878f-ff051279512b_3p_http
result, different session: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_3p_http,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_3p_http,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_3p_http
result, different session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_3p_http,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_3p_http,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_3p_http
unsupported: false, false, false
passed: false, false, false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session: , ,
result, different session: , ,
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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
passed: undefined
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_3p_http,
2233c25f-133b-4283-8605-f1b3293a7bd9_3p_http,
42b37351-62ab-4493-8ca7-365d6a7f4847_3p_http
result, different session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_3p_http,
2233c25f-133b-4283-8605-f1b3293a7bd9_3p_http,
42b37351-62ab-4493-8ca7-365d6a7f4847_3p_http
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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: , 7bf7d308-02fa-44f1-8c73-ae9ae1e01306_3p_http
result, different session: , 7bf7d308-02fa-44f1-8c73-ae9ae1e01306_3p_http
unsupported: true, false
passed: , false
test failed: 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=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
9978c55e-bfb4-434b-b846-23d42090a687_3p_js,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_3p_js,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_3p_js
result, different session: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_3p_js,
f2da4c27-b927-49c2-9e18-25f272c9328f_3p_js,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_3p_js
result, different session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_3p_js,
f2da4c27-b927-49c2-9e18-25f272c9328f_3p_js,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_3p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: ,
result, different session: ,
unsupported: true, true
passed: undefined
test failed: false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${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
passed: undefined
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_3p_js,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_3p_js,
6df13641-2d34-4529-b349-3c5772849016_3p_js
result, different session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_3p_js,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_3p_js,
6df13641-2d34-4529-b349-3c5772849016_3p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
03ddb668-d164-434b-8703-85d4fc2e66dc_3p_js,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_3p_js,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_3p_js
result, different session:
03ddb668-d164-434b-8703-85d4fc2e66dc_3p_js,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_3p_js,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_3p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_3p_js,
7e3c6442-4764-430e-ac99-8d3376daab80_3p_js,
916da71a-153b-4626-878f-ff051279512b_3p_js
result, different session: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_3p_js,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_3p_js,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_3p_js
result, different session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_3p_js,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_3p_js,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_3p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: , ,
result, different session: , ,
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${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
passed: undefined
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_3p_js,
2233c25f-133b-4283-8605-f1b3293a7bd9_3p_js,
42b37351-62ab-4493-8ca7-365d6a7f4847_3p_js
result, different session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_3p_js,
2233c25f-133b-4283-8605-f1b3293a7bd9_3p_js,
42b37351-62ab-4493-8ca7-365d6a7f4847_3p_js
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: , 7bf7d308-02fa-44f1-8c73-ae9ae1e01306_3p_js
result, different session: , 7bf7d308-02fa-44f1-8c73-ae9ae1e01306_3p_js
unsupported: true, false
passed: , false
test failed: 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:
9978c55e-bfb4-434b-b846-23d42090a687_3p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_3p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_3p
result, different session: , ,
unsupported: false, false, false
passed: true, true, true
test failed: 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 session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_3p,
f2da4c27-b927-49c2-9e18-25f272c9328f_3p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_3p
result, different session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_3p,
f2da4c27-b927-49c2-9e18-25f272c9328f_3p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_3p
unsupported: false, false, false
passed: false, false, false
test failed: 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
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
passed: undefined
test failed: 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 session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_3p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_3p,
6df13641-2d34-4529-b349-3c5772849016_3p
result, different session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_3p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_3p,
6df13641-2d34-4529-b349-3c5772849016_3p
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: true, true, true
passed: undefined
test failed: 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
result, different session:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: true, true, true
passed: undefined
test failed: 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 session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_3p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_3p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_3p
result, different session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_3p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_3p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_3p
unsupported: false, false, false
passed: false, false, false
test failed: 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
passed: undefined
test failed: 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
result, different session:
Error: Unsupported,
Error: Unsupported
unsupported: true, true
passed: undefined
test failed: 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 session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_3p,
2233c25f-133b-4283-8605-f1b3293a7bd9_3p,
42b37351-62ab-4493-8ca7-365d6a7f4847_3p
result, different session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_3p,
2233c25f-133b-4283-8605-f1b3293a7bd9_3p,
42b37351-62ab-4493-8ca7-365d6a7f4847_3p
unsupported: false, false, false
passed: false, false, false
test failed: 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 session: , 7bf7d308-02fa-44f1-8c73-ae9ae1e01306_3p
result, different session: , 7bf7d308-02fa-44f1-8c73-ae9ae1e01306_3p
unsupported: true, false
passed: , false
test failed: 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.
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_13701908661772477,
fake_7335769880511802,
fake_6789443205525427
result, different session:
fake_13701908661772477,
fake_7335769880511802,
fake_6789443205525427
unsupported: false, false, false
passed: false, false, false
test failed: 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_2606214166941896,
fake_98892331874411,
fake_16715275003583763
result, different session:
fake_2606214166941896,
fake_98892331874411,
fake_16715275003583763
unsupported: false, false, false
passed: false, false, false
test failed: 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_9709609440332068,
fake_3035006232703512
result, different session:
fake_9709609440332068,
fake_3035006232703512
unsupported: false, false
passed: false, false
test failed: 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_8902596237771276,
fake_27654904796171054,
fake_07993483919583322
result, different session:
fake_8902596237771276,
fake_27654904796171054,
fake_07993483919583322
unsupported: false, false, false
passed: false, false, false
test failed: 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_8700454849283183,
fake_47240549587205005,
fake_6250719364349695
result, different session:
fake_8700454849283183,
fake_47240549587205005,
fake_6250719364349695
unsupported: false, false, false
passed: false, false, false
test failed: 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_9463367888024996,
fake_1675031346189122,
fake_10423592763967737
result, different session:
fake_9463367888024996,
fake_1675031346189122,
fake_10423592763967737
unsupported: false, false, false
passed: false, false, false
test failed: 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_9222907956780206,
fake_614073889740024,
fake_9122092430901363
result, different session:
fake_9919063088219755,
fake_21036631845457499,
fake_16012924420296515
unsupported: false, false, false
passed: true, true, true
test failed: 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_0652015928223495,
fake_7183730413419567,
fake_4768646863392392
result, different session:
fake_0652015928223495,
fake_7183730413419567,
fake_4768646863392392
unsupported: false, false, false
passed: false, false, false
test failed: 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_02429344528697097,
fake_2286816423593796,
fake_9392838026813912
result, different session:
fake_02429344528697097,
fake_2286816423593796,
fake_9392838026813912
unsupported: false, false, false
passed: false, false, false
test failed: 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_008485564663313516,
fake_47038794296878916
result, different session:
fake_11145116128505905,
fake_03129273052393322
unsupported: false, false
passed: true, true
test failed: 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_7761095145045331,
fake_7556630848150618,
fake_6787302999490874
result, different session:
fake_7761095145045331,
fake_7556630848150618,
fake_6787302999490874
unsupported: false, false, false
passed: false, false, false
test failed: 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_22819427598693998,
fake_3450278961432762
result, different session:
fake_22819427598693998,
fake_3450278961432762
unsupported: false, false
passed: false, false
test failed: 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.
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
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
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
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Unsupported
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:
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
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Unsupported
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:
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
unsupported: true, true, true
passed: undefined
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
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
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
font cache
Web fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
9978c55e-bfb4-434b-b846-23d42090a687_3p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_3p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_3p
result, different session:
9978c55e-bfb4-434b-b846-23d42090a687_3p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_3p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_3p,
f2da4c27-b927-49c2-9e18-25f272c9328f_3p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_3p
result, different session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_3p,
f2da4c27-b927-49c2-9e18-25f272c9328f_3p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_3p
unsupported: false, false, false
passed: false, false, false
test failed: 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.
result, different session:
Error: The user denied permission to access the database.,
Error: The user denied permission to access the database.
unsupported: true, true
passed: undefined
test failed: false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_3p,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_3p,
c3405b81-ce4e-47fb-9288-741b29aece7c_3p
result, different session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_3p,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_3p,
c3405b81-ce4e-47fb-9288-741b29aece7c_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_3p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_3p,
6df13641-2d34-4529-b349-3c5772849016_3p
result, different session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_3p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_3p,
6df13641-2d34-4529-b349-3c5772849016_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
03ddb668-d164-434b-8703-85d4fc2e66dc_3p,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_3p,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_3p
result, different session:
03ddb668-d164-434b-8703-85d4fc2e66dc_3p,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_3p,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_3p
unsupported: false, false, false
passed: false, false, false
test failed: 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:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_3p,
7e3c6442-4764-430e-ac99-8d3376daab80_3p,
916da71a-153b-4626-878f-ff051279512b_3p
result, different session: undefined
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_3p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_3p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_3p
result, different session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_3p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_3p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_3p,
b752f8b5-1d43-4024-b85c-d0610aaad620_3p,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_3p
result, different session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_3p,
b752f8b5-1d43-4024-b85c-d0610aaad620_3p,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_3p
unsupported: false, false, false
passed: false, false, false
test failed: 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: IDBFactory.open: The operation is insecure,
Error: IDBFactory.open: The operation is insecure
result, different session:
Error: IDBFactory.open: The operation is insecure,
Error: IDBFactory.open: The operation is insecure
unsupported: true, true
passed: undefined
test failed: false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_3p,
2233c25f-133b-4283-8605-f1b3293a7bd9_3p,
42b37351-62ab-4493-8ca7-365d6a7f4847_3p
result, different session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_3p,
2233c25f-133b-4283-8605-f1b3293a7bd9_3p,
42b37351-62ab-4493-8ca7-365d6a7f4847_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
2769613e-97f8-44a3-837f-189b84b9e278_3p,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_3p
result, different session:
2769613e-97f8-44a3-837f-189b84b9e278_3p,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_3p
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
9978c55e-bfb4-434b-b846-23d42090a687_3p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_3p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_3p
result, different session:
9978c55e-bfb4-434b-b846-23d42090a687_3p,
56a6d2e4-9823-4238-8e1f-a5a862efc2aa_3p,
1f9112af-ba70-45ec-be2c-776fdc1d7dbc_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_3p,
f2da4c27-b927-49c2-9e18-25f272c9328f_3p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_3p
result, different session:
d7ee9d12-7df5-4a82-b115-15b2e9f531d1_3p,
f2da4c27-b927-49c2-9e18-25f272c9328f_3p,
4de0e09a-506a-4647-a0a4-a42e98b7f5dc_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Unsupported
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.,
Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.
result, different session:
Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.,
Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.
unsupported: true, true
passed: undefined
test failed: false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_3p,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_3p,
c3405b81-ce4e-47fb-9288-741b29aece7c_3p
result, different session:
a57cc61c-4dad-4d58-8993-b1599b60f30d_3p,
aa5d30c0-0c9c-4088-ada9-3428936be9b2_3p,
c3405b81-ce4e-47fb-9288-741b29aece7c_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_3p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_3p,
6df13641-2d34-4529-b349-3c5772849016_3p
result, different session:
4b6d1163-5e20-4f4b-909f-2e990ac4d13c_3p,
715f3890-7ef6-4e6d-8c5e-f67837724eb4_3p,
6df13641-2d34-4529-b349-3c5772849016_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
03ddb668-d164-434b-8703-85d4fc2e66dc_3p,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_3p,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_3p
result, different session:
03ddb668-d164-434b-8703-85d4fc2e66dc_3p,
1c00c1f6-a501-46c5-aeb4-476b0e14c57d_3p,
69d2c505-d494-4fd1-b2c7-f0c5ad702fc8_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
cee0a24e-86b6-4713-865e-7c8c9dbc0330_3p,
7e3c6442-4764-430e-ac99-8d3376daab80_3p,
916da71a-153b-4626-878f-ff051279512b_3p
result, different session: , ,
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_3p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_3p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_3p
result, different session:
c5490f42-7fe7-4bbe-81bf-ef30a44999a5_3p,
c2905ef6-4c9e-4027-8a34-105ee0be95a2_3p,
8c45d9ed-f12b-4b35-8bdd-b280be7b5572_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_3p,
b752f8b5-1d43-4024-b85c-d0610aaad620_3p,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_3p
result, different session:
bef24721-ae28-44cf-b4e7-18ba6b47af22_3p,
b752f8b5-1d43-4024-b85c-d0610aaad620_3p,
3fdec9c8-cd8e-42b4-9e1d-a8a3e8a4b0e2_3p
unsupported: false, false, false
passed: false, false, false
test failed: 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.
result, different session:
Error: The operation is insecure.,
Error: The operation is insecure.
unsupported: true, true
passed: undefined
test failed: false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_3p,
2233c25f-133b-4283-8605-f1b3293a7bd9_3p,
42b37351-62ab-4493-8ca7-365d6a7f4847_3p
result, different session:
0f00b752-b58d-4191-84f3-6ca6518adaf2_3p,
2233c25f-133b-4283-8605-f1b3293a7bd9_3p,
42b37351-62ab-4493-8ca7-365d6a7f4847_3p
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
2769613e-97f8-44a3-837f-189b84b9e278_3p,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_3p
result, different session:
2769613e-97f8-44a3-837f-189b84b9e278_3p,
7bf7d308-02fa-44f1-8c73-ae9ae1e01306_3p
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session:
Error: No requests received,
Error: No requests received
unsupported: true, true
passed: undefined
test failed: false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: 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, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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.
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2, 2
unsupported: false, false, false
passed: true, true, true
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: 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
result, different session: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1, 1
result, different session: 1, 1, 1
unsupported: false, false, false
passed: false, false, false
test failed: false, false, false
Failed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false