Android Browsers

(default settings)
brave logo
brave
1.81
chrome logo
chrome
139.0
cromite logo
cromite
130.0
duckduckgo logo
duckduckgo
5.243
edge logo
edge
138.0
firefox logo
firefox
141.0
focus logo
focus
141.0
opera logo
opera
90.6
samsung logo
samsung
28.0
tor logo
tor
14.5
vivaldi logo
vivaldi
7.5
yandex logo
yandex
25.6
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
result, different first party: h2, h2
unsupported: false, false
passed: true, true
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
result, different first party: h2, h2
unsupported: false, false
passed: true, true
test failed: false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }
read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }
result, same first party: Error: Unsupported
result, different first party: h2
unsupported: true
passed: undefined
test failed: false
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
result, different first party: h3, h3
unsupported: false, false
passed: false, false
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
result, different first party: h2, h2
unsupported: false, false
passed: true, true
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
result, different first party: h2, h2
unsupported: false, false
passed: true, true
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
result, different first party: h2, h2
unsupported: false, false
passed: true, true
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
result, different first party: h2, h2
unsupported: false, false
passed: true, true
test failed: 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
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }
read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }
result, same first party: Error: Unsupported
result, different first party: h2
unsupported: true
passed: undefined
test failed: false
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
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
result, different first party: h2
unsupported: false
passed: true
test failed: 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=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${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
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=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party: Error: Failed to fetch
result, different first party: Error: Failed to fetch
unsupported: false
passed: true
test failed: false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
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=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${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: 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=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.
result, different first party:
Error: NetworkError when attempting to fetch resource.,
Error: NetworkError when attempting to fetch resource.
unsupported: false, false
passed: undefined
test failed: true, true
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${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
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=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${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: NetworkError when attempting to fetch resource.
result, different first party: Error: NetworkError when attempting to fetch resource.
unsupported: false
passed: undefined
test failed: true
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async (secret) => {
      let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
      let result = await response.json();
      let blobUrl = decodeURIComponent(result.blobUrl);
      let blobResponse = await fetch(blobUrl);
      return blobResponse.text();
    }
result, same first party:
Error: Failed to fetch,
Error: Failed to fetch
result, different first party:
Error: Failed to fetch,
Error: Failed to fetch
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (secret) => {
      try {
        let blobURL = URL.createObjectURL(new Blob([secret]));
        fetch(`${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
result, different first party: Error: Failed to fetch
unsupported: false
passed: true
test failed: 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
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
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
result, different first party: Error: no BroadcastChannel message
unsupported: false
passed: undefined
test failed: true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
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
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
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
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
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
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
result, different first party: Error: The operation is insecure.
unsupported: false
passed: undefined
test failed: true
Passed
write: (secret) => {
      try {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data === "request") {
            bc.postMessage(secret);
          }
        };
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () =>
      new Promise((resolve, reject) => {
        let bc = new BroadcastChannel("secrets");
        bc.onmessage = (event) => {
          if (event.data !== "request") {
            resolve(event.data);
          }
        };
        bc.postMessage("request");
        setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000);
      })
result, same first party:
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
result, different first party: Error: no BroadcastChannel message
unsupported: false
passed: undefined
test failed: 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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
fb524904-5702-43e1-ac11-04c5cf20f587,
fb524904-5702-43e1-ac11-04c5cf20f587
result, different first party:
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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
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
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party: 2f149f9d-7d24-4463-baa9-df54b4e81d63
result, different first party: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.
unsupported: false
passed: true
test failed: false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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
result, different first party:
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p,
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0
result, different first party:
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
39122539-ac2b-4685-b7fc-0e032c9e090b,
39122539-ac2b-4685-b7fc-0e032c9e090b
result, different first party:
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined
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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
69e5b0e4-70f8-48e9-9743-0c8924e002e0,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389
result, different first party:
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
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')
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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
a31f089a-366d-46aa-8a3d-39c59eae3ef3_3p,
a31f089a-366d-46aa-8a3d-39c59eae3ef3_3p
result, different first party:
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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: 7938b722-8d2a-43e4-9a9c-5c6862a8801a
result, different first party: Error: The operation is insecure.
unsupported: false
passed: true
test failed: false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same first party:
1af58a1e-55c5-4125-ba6b-5729d21fd23c,
1af58a1e-55c5-4125-ba6b-5729d21fd23c
result, different first party:
Error: Cannot read properties of undefined (reading 'url'),
Error: Cannot read properties of undefined (reading 'url')
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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
result, different first party: Error: Cannot read properties of undefined (reading 'url')
unsupported: false
passed: true
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_http,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_http
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_http,
3994da5b-a26d-4958-affd-b8e0c773fe1f_http
result, different first party:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_http,
3994da5b-a26d-4958-affd-b8e0c773fe1f_http
unsupported: false, false
passed: false, false
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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43_http
result, different first party: null
unsupported: false
passed: true
test failed: false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_http,
75ad195c-7360-4024-acbd-7cc73f3a88da_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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
697630c9-dcc2-4455-8a29-27655f87372d_http,
b0b81741-ce0a-4da9-a847-8546019db2c8_http
result, different first party:
697630c9-dcc2-4455-8a29-27655f87372d_http,
b0b81741-ce0a-4da9-a847-8546019db2c8_http
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_http,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_http,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_http
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
e866cb47-f99b-49ef-9363-fff628d0cdf2_http,
30ed29fc-999b-4192-8147-b8ac04c45a12_http
result, different first party:
e866cb47-f99b-49ef-9363-fff628d0cdf2_http,
30ed29fc-999b-4192-8147-b8ac04c45a12_http
unsupported: false, false
passed: false, false
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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
02fa9553-d71b-467b-83b5-a138eda6698d_http,
8730e3a9-f808-4678-bf99-7c0bee79f73c_http
result, different first party:
02fa9553-d71b-467b-83b5-a138eda6698d_http,
8730e3a9-f808-4678-bf99-7c0bee79f73c_http
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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: 7938b722-8d2a-43e4-9a9c-5c6862a8801a_http
result, different first party: null
unsupported: false
passed: true
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same first party:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_http,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_http
result, different first party:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_http,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_http
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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: 3012f5f3-b088-4785-a968-57354668da41_http
result, different first party: 3012f5f3-b088-4785-a968-57354668da41_http
unsupported: false
passed: false
test failed: 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=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_js,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_js
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_js,
3994da5b-a26d-4958-affd-b8e0c773fe1f_js
result, different first party:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_js,
3994da5b-a26d-4958-affd-b8e0c773fe1f_js
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43_js
result, different first party: null
unsupported: false
passed: true
test failed: false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_js,
75ad195c-7360-4024-acbd-7cc73f3a88da_js
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
697630c9-dcc2-4455-8a29-27655f87372d_js,
b0b81741-ce0a-4da9-a847-8546019db2c8_js
result, different first party:
697630c9-dcc2-4455-8a29-27655f87372d_js,
b0b81741-ce0a-4da9-a847-8546019db2c8_js
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_js,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_js
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_js,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_js
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
e866cb47-f99b-49ef-9363-fff628d0cdf2_js,
30ed29fc-999b-4192-8147-b8ac04c45a12_js
result, different first party:
e866cb47-f99b-49ef-9363-fff628d0cdf2_js,
30ed29fc-999b-4192-8147-b8ac04c45a12_js
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
02fa9553-d71b-467b-83b5-a138eda6698d_js,
8730e3a9-f808-4678-bf99-7c0bee79f73c_js
result, different first party:
02fa9553-d71b-467b-83b5-a138eda6698d_js,
8730e3a9-f808-4678-bf99-7c0bee79f73c_js
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party: 7938b722-8d2a-43e4-9a9c-5c6862a8801a_js
result, different first party: null
unsupported: false
passed: true
test failed: false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_js,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_js
result, different first party:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_js,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_js
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party: 3012f5f3-b088-4785-a968-57354668da41_js
result, different first party: 3012f5f3-b088-4785-a968-57354668da41_js
unsupported: false
passed: false
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2
result, different first party: ,
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 first party:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892,
3994da5b-a26d-4958-affd-b8e0c773fe1f
result, different first party:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892,
3994da5b-a26d-4958-affd-b8e0c773fe1f
unsupported: false, false
passed: false, false
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: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43
result, different first party: null
unsupported: false
passed: true
test failed: 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:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
result, different first party: ,
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 first party:
697630c9-dcc2-4455-8a29-27655f87372d,
b0b81741-ce0a-4da9-a847-8546019db2c8
result, different first party:
697630c9-dcc2-4455-8a29-27655f87372d,
b0b81741-ce0a-4da9-a847-8546019db2c8
unsupported: false, false
passed: false, false
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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f
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:
69e5b0e4-70f8-48e9-9743-0c8924e002e0,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389
result, different first party: ,
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 first party:
e866cb47-f99b-49ef-9363-fff628d0cdf2,
30ed29fc-999b-4192-8147-b8ac04c45a12
result, different first party:
e866cb47-f99b-49ef-9363-fff628d0cdf2,
30ed29fc-999b-4192-8147-b8ac04c45a12
unsupported: false, false
passed: false, false
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:
02fa9553-d71b-467b-83b5-a138eda6698d,
8730e3a9-f808-4678-bf99-7c0bee79f73c
result, different first party:
02fa9553-d71b-467b-83b5-a138eda6698d,
8730e3a9-f808-4678-bf99-7c0bee79f73c
unsupported: false, false
passed: false, false
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 first party: Error: Unsupported
result, different first party: Error: Unsupported
unsupported: true
passed: undefined
test failed: 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:
e000bc57-a9e3-4fec-a11f-37fae427b3ee,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93
result, different first party:
e000bc57-a9e3-4fec-a11f-37fae427b3ee,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93
unsupported: false, false
passed: false, false
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: 3012f5f3-b088-4785-a968-57354668da41
result, different first party: 3012f5f3-b088-4785-a968-57354668da41
unsupported: false
passed: false
test failed: 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_6146587863151454,
fake_17851706804774703
result, different first party:
fake_4139291980824513,
fake_16203901259316056
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_2557567432339938,
fake_9372352941122895
result, different first party:
fake_6138351584640305,
fake_9045393291510317
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_9611241958020287
result, different first party: fake_06453059347131473
unsupported: false
passed: true
test failed: 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_4404124071183051,
fake_715116005479719
result, different first party:
fake_4404124071183051,
fake_715116005479719
unsupported: false, false
passed: false, false
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_3574498960984549,
fake_06273130466644994
result, different first party:
fake_5520346998530385,
fake_7570598719677164
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_22411328090120408,
fake_9975431269254873
result, different first party:
fake_8653185150454352,
fake_3586736623795612
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_5791339176256134,
fake_2135278865964363
result, different first party:
fake_8964328648604376,
fake_595412732537064
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_9532364199424401,
fake_548992846222147
result, different first party:
fake_8088966821729413,
fake_8864431274345819
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_5134388302563127,
fake_5935472685105199
result, different first party:
fake_7199269521117955,
fake_6923525224543876
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_5465586079842573
result, different first party: fake_6505070490931608
unsupported: false
passed: true
test failed: false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }
read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }
result, same first party:
fake_20657341176983168,
fake_6662324980484475
result, different first party:
fake_5337058616718215,
fake_6699107383526708
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_7335193359370535
result, different first party: fake_1491008540581118
unsupported: false
passed: true
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same first party: 1, 1
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same first party: 1
result, different first party: 2
unsupported: false
passed: true
test failed: 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
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
result, different first party: 1, 1
unsupported: false, false
passed: false, false
test failed: 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
result, different first party:
Error: No requests received,
Error: No requests received
unsupported: true, true
passed: undefined
test failed: 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
result, different first party:
Error: No requests received,
Error: No requests received
unsupported: true, true
passed: undefined
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
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
result, different first party: 1
unsupported: false
passed: false
test failed: false
Passed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same first party: 1, 1
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
      await sleepMs(2000);
      let response = await fetch(
        testURI("ctr", "favicon", key), {"cache": "reload"});
      let count = (await response.text()).trim();
      if (count === "0") {
        throw new Error("No requests received");
      }
      return count;
    }
result, same first party: 1
result, different first party: 2
unsupported: false
passed: true
test failed: 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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: 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
result, different first party: 1, 1
unsupported: false, false
passed: false, false
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
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
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
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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same first party: 1, 1
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same first party: 1
result, different first party: 2
unsupported: false
passed: true
test failed: 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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: 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
result, different first party: 1, 1
unsupported: false, false
passed: false, false
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
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
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
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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same first party: 1, 1
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same first party: 1
result, different first party: 2
unsupported: false
passed: true
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2
result, different first party:
Error: Unsupported,
Error: Unsupported
unsupported: false, false
passed: true, true
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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892,
3994da5b-a26d-4958-affd-b8e0c773fe1f
result, different first party:
Error: Unsupported,
Error: Unsupported
unsupported: false, false
passed: true, true
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: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43
result, different first party: Error: Unsupported
unsupported: false
passed: true
test failed: 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:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
result, different first party:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
unsupported: false, false
passed: false, false
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:
697630c9-dcc2-4455-8a29-27655f87372d,
b0b81741-ce0a-4da9-a847-8546019db2c8
result, different first party:
Error: Unsupported,
Error: Unsupported
unsupported: false, false
passed: true, true
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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f
result, different first party:
Error: Unsupported,
Error: Unsupported
unsupported: false, false
passed: true, true
test failed: 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:
e866cb47-f99b-49ef-9363-fff628d0cdf2,
30ed29fc-999b-4192-8147-b8ac04c45a12
result, different first party:
Error: Unsupported,
Error: Unsupported
unsupported: false, false
passed: true, true
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:
02fa9553-d71b-467b-83b5-a138eda6698d,
8730e3a9-f808-4678-bf99-7c0bee79f73c
result, different first party:
Error: Unsupported,
Error: Unsupported
unsupported: false, false
passed: true, true
test failed: false, false
Unsupported
write: async (secret) => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt", { create: true });
        const stream = await fileHandle.createWritable();
        await stream.write(secret);
        await stream.close();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      try {
        const root = await navigator.storage.getDirectory();
        const fileHandle = await root.getFileHandle("secret.txt");
        const file = await fileHandle.getFile();
        return file.text();
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
result, same first party: Error: Unsupported
result, different first party: Error: Unsupported
unsupported: true
passed: undefined
test failed: false
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:
e000bc57-a9e3-4fec-a11f-37fae427b3ee,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93
result, different first party:
Error: Unsupported,
Error: Unsupported
unsupported: false, false
passed: true, true
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: 3012f5f3-b088-4785-a968-57354668da41
result, different first party: Error: Unsupported
unsupported: false
passed: true
test failed: 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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892,
3994da5b-a26d-4958-affd-b8e0c773fe1f
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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43
result, different first party:
unsupported: false
passed: true
test failed: false
Failed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
result, different first party:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
697630c9-dcc2-4455-8a29-27655f87372d,
b0b81741-ce0a-4da9-a847-8546019db2c8
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f
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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
69e5b0e4-70f8-48e9-9743-0c8924e002e0,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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:
e866cb47-f99b-49ef-9363-fff628d0cdf2,
30ed29fc-999b-4192-8147-b8ac04c45a12
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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
02fa9553-d71b-467b-83b5-a138eda6698d,
8730e3a9-f808-4678-bf99-7c0bee79f73c
result, different first party:
02fa9553-d71b-467b-83b5-a138eda6698d,
8730e3a9-f808-4678-bf99-7c0bee79f73c
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: 7938b722-8d2a-43e4-9a9c-5c6862a8801a
result, different first party:
unsupported: false
passed: true
test failed: false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
e000bc57-a9e3-4fec-a11f-37fae427b3ee,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: 3012f5f3-b088-4785-a968-57354668da41
result, different first party:
unsupported: false
passed: true
test failed: 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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892,
3994da5b-a26d-4958-affd-b8e0c773fe1f
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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43
result, different first party:
unsupported: false
passed: true
test failed: false
Failed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
result, different first party:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
697630c9-dcc2-4455-8a29-27655f87372d,
b0b81741-ce0a-4da9-a847-8546019db2c8
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f
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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
69e5b0e4-70f8-48e9-9743-0c8924e002e0,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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:
e866cb47-f99b-49ef-9363-fff628d0cdf2,
30ed29fc-999b-4192-8147-b8ac04c45a12
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=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
02fa9553-d71b-467b-83b5-a138eda6698d,
8730e3a9-f808-4678-bf99-7c0bee79f73c
result, different first party:
02fa9553-d71b-467b-83b5-a138eda6698d,
8730e3a9-f808-4678-bf99-7c0bee79f73c
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: 7938b722-8d2a-43e4-9a9c-5c6862a8801a
result, different first party:
unsupported: false
passed: true
test failed: false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"});
    }
read: async () => {
      let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"});
      return await response.text();
    }
result, same first party:
e000bc57-a9e3-4fec-a11f-37fae427b3ee,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: 3012f5f3-b088-4785-a968-57354668da41
result, different first party:
unsupported: false
passed: true
test failed: 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:
cb3003dbc2eda2d4f4c8ad481be3a43c,
f1d66a8f56840e00b436751558bea7dc
result, different first party:
e121b8658785ecf143861a50601a7a9d,
5a7ae0017088c5ef649ed516c5554e47
unsupported: false, false
passed: true, true
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:
050a3d91ab9014f6983dba220b15fb8a,
708dcda265f901ccc7428a0548a464ef
result, different first party:
2495ec38611094546e96796a5eb76c1e,
040d74f764f47234afa530f78bb655f5
unsupported: false, false
passed: true, true
test failed: false, false
Unsupported
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }
result, same first party:
result, different first party:
unsupported: true
passed: undefined
test failed: false
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:
34235f4e4cbbba1fb99d96dacab67a34,
c30ef07559abd07b90954de6529cbdbf
result, different first party:
34235f4e4cbbba1fb99d96dacab67a34,
c30ef07559abd07b90954de6529cbdbf
unsupported: false, false
passed: false, false
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:
af94fca5c1e938d3d40165e5400d392c,
094f174d44f62a3237a279ef9d2ec8ff
result, different first party:
ff6fc85c9a2ea90fd4695d9bf51d55d9,
a8d7ccd59240a2bda59fed843a57e9e6
unsupported: false, false
passed: true, true
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:
43d8844ddf54e602e26aabe50d2c3e1b,
43fa09960eb9cdd522c4b018807ce8fd
result, different first party:
cded69552dfb8a615e934e52929d69eb,
b0cbd133af50f4368495bc7e24b7690c
unsupported: false, false
passed: true, true
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:
e0382d0d18d6a4f51f0c1628f2c841dd,
aa53693358fc0a110b4c1f1aaba2af15
result, different first party: ,
unsupported: false, false
passed: true, true
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:
f76c36e45c4b8616a77efa70d31937d3,
49f62ee85cf5b0f49c5ff3934da79f60
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: 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
Unsupported
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
      for (let i = 0; i<3; ++i) {
        await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
        await sleepMs(500);
      }
      // Are we now connecting over h3?
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"});
      let text = await response.text();
      // Empty response text indicates we are not connecting over h3:
      if (text.trim() === "") {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`);
      return await response.text();
    }
result, same first party:
result, different first party:
unsupported: true
passed: undefined
test failed: false
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:
d9480e697eff36a64c371c4425d76ea1,
1fbec30906b749225f9c06f6c63ba527
result, different first party:
c6fd6847b164c0d53ae38728189624a5,
7623896ae487fd6e18501e36139abf18
unsupported: false, false
passed: true, true
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: b2199bfaccf8f185f1b427bfcf04372f
result, different first party: 17743e84cf2cf34ea2ce98b97757a231
unsupported: false
passed: true
test failed: 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
result, different first party: Used http, Used http
unsupported: false, false
passed: true, true
test failed: 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
Passed
write: null
read: null
result, same first party: null
result, different first party: HTTPS used by default; no HSTS cache issue expected
unsupported: null
passed: true
test failed: 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
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
Passed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested
result, different first party: Used http, Used http
unsupported: false, false
passed: true, true
test failed: 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
result, different first party:
Upgraded to https,
Upgraded to https
unsupported: false, false
passed: false, false
test failed: 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
Passed
write: null
read: null
result, same first party: null
result, different first party: HTTPS used by default; no HSTS cache issue expected
unsupported: null
passed: true
test failed: 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
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested
result, different first party: Upgraded to https
unsupported: false
passed: false
test failed: 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
result, different first party: Used http, Used http
unsupported: false, false
passed: true, true
test failed: 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
Passed
write: null
read: null
result, same first party: null
result, different first party: HTTPS used by default; no HSTS cache issue expected
unsupported: null
passed: true
test failed: 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
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
Passed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested
result, different first party: Used http, Used http
unsupported: false, false
passed: true, true
test failed: 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
result, different first party:
Upgraded to https,
Upgraded to https
unsupported: false, false
passed: false, false
test failed: 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
Passed
write: null
read: null
result, same first party: null
result, different first party: HTTPS used by default; no HSTS cache issue expected
unsupported: null
passed: true
test failed: 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
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested
result, different first party: Upgraded to https
unsupported: false
passed: false
test failed: 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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: 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
result, different first party: 1, 1
unsupported: false, false
passed: false, false
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
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
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
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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same first party: 1, 1
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same first party: 1
result, different first party: 2
unsupported: false
passed: true
test failed: 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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: 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
result, different first party: 1, 1
unsupported: false, false
passed: false, false
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
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
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
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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same first party: 1, 1
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same first party: 1
result, different first party: 2
unsupported: false
passed: true
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2
result, different first party: undefined
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same first party:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892,
3994da5b-a26d-4958-affd-b8e0c773fe1f
result, different first party: undefined
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same first party: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43
result, different first party: Error: The user denied permission to access the database.
unsupported: false
passed: true
test failed: 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:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
result, different first party:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
unsupported: false, false
passed: false, false
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:
697630c9-dcc2-4455-8a29-27655f87372d,
b0b81741-ce0a-4da9-a847-8546019db2c8
result, different first party: undefined
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same first party:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f
result, different first party: undefined
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same first party:
69e5b0e4-70f8-48e9-9743-0c8924e002e0,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389
result, different first party: undefined
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same first party:
e866cb47-f99b-49ef-9363-fff628d0cdf2,
30ed29fc-999b-4192-8147-b8ac04c45a12
result, different first party: undefined
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same first party:
02fa9553-d71b-467b-83b5-a138eda6698d,
8730e3a9-f808-4678-bf99-7c0bee79f73c
result, different first party: undefined
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same first party: 7938b722-8d2a-43e4-9a9c-5c6862a8801a
result, different first party: Error: IDBFactory.open: The operation is insecure
unsupported: false
passed: true
test failed: false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same first party:
e000bc57-a9e3-4fec-a11f-37fae427b3ee,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93
result, different first party: undefined
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same first party: 3012f5f3-b088-4785-a968-57354668da41
result, different first party: undefined
unsupported: false
passed: true
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2
result, different first party: ,
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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892,
3994da5b-a26d-4958-affd-b8e0c773fe1f
result, different first party: ,
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: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43
result, different first party: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.
unsupported: false
passed: true
test failed: false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
result, different first party:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
697630c9-dcc2-4455-8a29-27655f87372d,
b0b81741-ce0a-4da9-a847-8546019db2c8
result, different first party: ,
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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f
result, different first party: ,
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:
69e5b0e4-70f8-48e9-9743-0c8924e002e0,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389
result, different first party: ,
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:
e866cb47-f99b-49ef-9363-fff628d0cdf2,
30ed29fc-999b-4192-8147-b8ac04c45a12
result, different first party: ,
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:
02fa9553-d71b-467b-83b5-a138eda6698d,
8730e3a9-f808-4678-bf99-7c0bee79f73c
result, different first party: ,
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: 7938b722-8d2a-43e4-9a9c-5c6862a8801a
result, different first party: Error: The operation is insecure.
unsupported: false
passed: true
test failed: false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same first party:
e000bc57-a9e3-4fec-a11f-37fae427b3ee,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93
result, different first party: ,
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: 3012f5f3-b088-4785-a968-57354668da41
result, different first party: null
unsupported: false
passed: true
test failed: 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')
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
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
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')
result, different first party: Error: The request was denied.
unsupported: false
passed: undefined
test failed: true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
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
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
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: can't access property "name",
queryResult.held[0] is undefined,
Error: can't access property "name",
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: can't access property "name",
queryResult.held[0] is undefined,
Error: can't access property "name",
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')
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
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
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
result, different first party: Error: LockManager.query: query() is not allowed in this context
unsupported: false
passed: undefined
test failed: true
Passed
write: async (key) => {
      if (navigator.locks) {
        navigator.locks.request(key, lock => new Promise((f,r) => {}));
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].clientId;
      } else {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (navigator.locks) {
        let queryResult = await navigator.locks.query();
        return queryResult.held[0].name;
      }
    }
result, same first party:
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
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')
result, different first party: Error: Cannot read properties of undefined (reading 'name')
unsupported: false
passed: undefined
test failed: 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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
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
result, different first party: 2
unsupported: false
passed: true
test failed: 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
result, different first party: 1, 1
unsupported: false, false
passed: false, false
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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
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
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same first party: Error: No requests received
result, different first party: Error: No requests received
unsupported: true
passed: undefined
test failed: false
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: 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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: 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
result, different first party: 1, 1
unsupported: false, false
passed: false, false
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
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
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
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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: false
Passed
write: (key) => new Promise((resolve, reject) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })
read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same first party: 1, 1
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })
read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same first party: 1
result, different first party: 2
unsupported: false
passed: true
test failed: 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=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: ,
result, different first party: ,
unsupported: false, false
passed: undefined
test failed: true, true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${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
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=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party:
result, different first party: Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker.
unsupported: false
passed: undefined
test failed: true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${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
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=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: ,
result, different first party: ,
unsupported: false, false
passed: undefined
test failed: true, true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${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
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=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: ,
result, different first party: ,
unsupported: false, false
passed: undefined
test failed: true, true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${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
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=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: ,
result, different first party: ,
unsupported: false, false
passed: undefined
test failed: true, true
Unsupported
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${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
result, different first party: Error: navigator.serviceWorker is undefined
unsupported: true
passed: undefined
test failed: 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=${key}`);
    }
read: async () => {
      console.log("trying to register the serviceworker now...");
      const registration = await Promise.race([
        navigator.serviceWorker.register('serviceWorker.js'),
        sleepMs(500)
      ]);
      if (registration === undefined) {
        // We timed out or otherwise failed.
        throw new Error("ServiceWorker registration failed");
      }
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      let response = await fetch("serviceworker-read");
      return await response.text();
    }
result, same first party: ,
result, different first party: ,
unsupported: false, false
passed: undefined
test failed: true, true
Passed
write: async (key) => {
      if (!navigator.serviceWorker) {
        throw new Error("Unsupported");
      }
      let registration = await navigator.serviceWorker.register(
        'serviceWorker.js');
      console.log(registration);
      await navigator.serviceWorker.ready;
      console.log("service worker ready");
      await sleepMs(100);
      await fetch(`serviceworker-write?secret=${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
passed: undefined
test failed: 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
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
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
result, different first party: Error: SharedWorker is not defined
unsupported: true
passed: undefined
test failed: 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
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: Unsupported,
Error: Unsupported
result, different first party:
Error: Unsupported,
Error: Unsupported
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: Unsupported,
Error: Unsupported
result, different first party:
Error: Unsupported,
Error: Unsupported
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
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
result, different first party:
Error: SharedWorker is not defined,
Error: SharedWorker is not defined
unsupported: true, true
passed: undefined
test failed: false, false
Passed
write: async (secret) => {
      try {
        let worker = new SharedWorker("supercookies_sharedworker.js");
        worker.port.start();
//        console.log("worker", worker);
        const messagePromise = new Promise((resolve) => {
          worker.port.onmessage = (e) => resolve(e.data);
        });
        worker.port.postMessage(secret);
        await messagePromise;
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let worker = new SharedWorker("supercookies_sharedworker.js");
      worker.port.start();
      const messagePromise = new Promise((resolve, reject) => {
        worker.port.onmessage = (e) => resolve(e.data);
        setTimeout(() => reject(new Error("no SharedWorker message received")), 200);
      });
      worker.port.postMessage("request");
      const message = await messagePromise;
      if (message === "none") {
        throw new Error("Unsupported");
      }
      return message;
    }
result, same first party: Error: no SharedWorker message received
result, different first party: Error: SharedWorker constructor: StorageAccess denied.
unsupported: false
passed: undefined
test failed: 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
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
result, different first party: Error: SharedWorker is not defined
unsupported: true
passed: undefined
test failed: 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:
fc07f30bb96d484cbb1f2ab5e4a2c3936188991e43318803d0162b237b5cc9ee,
6fdeafd3d67275f8331b1818035de873adce580e8113a08bc71e6da66d63dc64
result, different first party:
e8dd52b1745a6d6df886ae6a9f50f8cf775dc3b594cf33c5ccfe4da253709793,
3e9d3d538309ee6702c146524a3ed6b7dddf9f08e14b46d5f9f659b28fe8e107
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:
df1e72f13ff456d67b578aca6768a0ae398b90db6fa9c80751e5a3a94ad0add2,
72fafea974126615ad5fce644894ec928cd8b3deb712c337d29cde472b1e4461
result, different first party:
548dd1c743522b2f481163d1ebe09646f597b35aa8e54c19990a773d9efbaddf,
4706e79383c13f72fefbfe44f130318afdc6536dc8740e900c7aac7077cf5548
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: 41193368bccc8186751f27e9f1a8cf1edd692172dd1e33daf89604b6adff5b12
result, different first party: 3411245bdd41f751b5af3d106321e5793b988fe9a42dc7b22a0a5eb120afb844
unsupported: false
passed: true
test failed: false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }
read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }
result, same first party:
6bc62bd6c706c5bf4c1188b29882deb74b44ef2f6729aa8952bf638d75d88739,
8260d88e985b958a29767ece13a885d5ea18cc6ad2fec82fb43c9f3df3fa1277
result, different first party:
7fcfa4c318c89f5ab16348bbaccca6c82011d2ce6140c96c48234ebd1d89d07b,
90765a44a3bef235abdfe245a77f79aa63a9c6cabf974026598ce97240da2744
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:
43cb5df9571308bcc4b6b4d0a1bf86a10eb41c3ca30b78b734bc45fc41c9ff11,
027d91a61e405613a509e876eb38e4728353bcc82523e04ead881658533a8624
result, different first party:
dcb1b87f28ebb586d740e4f9c9936daa78d9265ece6dd9683dbe9bca6876efe8,
32b10113416ef56bcc05e7d3bfef50d6fe675da22ab9e3ed6021b2165c65d612
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:
3b62ffb953067ab5c1c3f8499a481583d27e0a5e9092b89b1f49e00e1d3ff33d,
92046b6b39b6b7c181aa744d52af4cb4807f031a1cb90faba1c4495fba73431f
result, different first party:
0eca65b82eb8cc1cb5e2d1e00459213f391f1ea007861a9c7e5d4eeff2349e37,
048e97620b3a9596939186ac52396bc6ec73ca5cfc6758a8294cf513078ddce9
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:
893ceb7ef341b1171ede153fcd3f440bc1ff6dceb5d35dd544f092015539db6f,
861280aab2e708e4fdc0bd78916e418ff28a4838a6ca6e0680b1d0a66aa3d5d4
result, different first party:
9381920fec7a4ae6359b18812544238a1e2d03cb5d9be356e6b5aaf653a9abf9,
9fb9dc7bae7451c864111c342ed18fbee45a854c6ff00b964da41ba63beb6e3f
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:
5cbe9d469a8c4c6ee25d0cbba30c55c850d136d69bd461d4301534c72a08f2fa,
fcfd1d064fa08a963f31e1de91a2d7db8ca885ce4fe454e29bb6afbe51a24c2a
result, different first party:
23ff6c9160b8b388dc50ff72101f67fe7788d65d7b4b00b392d10a236447919e,
d286f7393bdf24e33710f0eda357a5a95a92be34394c1516b3c41c3bba8e3dee
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:
d73b4ac25c84fcfe92e74f985970f017484e326f51f68090173b95800dd741f9,
6a68035f31465c21077060324a6edd2ef2ad62f4b1e62ef2634847241b1679b1
result, different first party:
638f192fb71539e31e780e86fe8623f3924c8acfe9d7106dc2f23091414f1668,
9dd276e488e160fab235e29ced2e5645c601b3b2c65425a0d6e2201cdbb6f02d
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: 9b2a78c578f0abbe54341f25ba9ec7f66e2d224472db3bdd54db4efaa1a29da0
result, different first party: 58369abc3cd23a3802c0a48e8dbf7a76048a711d4e9a0e1f4b87edea9eea16df
unsupported: false
passed: true
test failed: false
Passed
write: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }
read: async () => {
      let results = await fetch("https://tls.privacytests2.org:8900/");
      return (await results.json()).sessionId;
    }
result, same first party:
0a61f1d1ac73d47cdde27c6ad44d60ed89d31b8992ba7479f26695536102fd6a,
883c2983af1a59f6e4b2373f56874060e9613fd0581f17a632a2b61873e5cace
result, different first party:
1c477bcb2828b4833d0d2ee9f6849976ccd61224942f4347fe153e498cc78c0a,
a4e4fdb0862652904937f9605b489011d75903573959229638ab6efcc39caba4
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: a8c8ab3b28d1ed6250a9efa1dee1feb42bcd1f9e23e3ed433f3169a1f1761475
result, different first party: 08ff404e837855e30183a5c359c81c5114716961e4c80157a4a0147994eee597
unsupported: false
passed: true
test failed: 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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: 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
result, different first party: 1, 1
unsupported: false, false
passed: false, false
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
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
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
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
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
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
result, different first party: 2
unsupported: false
passed: true
test failed: false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same first party: 1, 1
result, different first party: 2, 2
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same first party: 1
result, different first party: 2
unsupported: false
passed: true
test failed: 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/
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/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party: https://test-pages.privacytests2.org/
result, different first party:
unsupported: false
passed: true
test failed: false
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
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/
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/
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/
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/
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/
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/
result, different first party: https://test-pages.privacytests2.org/
unsupported: false
passed: false
test failed: false
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party: https://test-pages.privacytests2.org/
result, different first party: https://test-pages.privacytests2.org/
unsupported: false
passed: false
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2
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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892,
3994da5b-a26d-4958-affd-b8e0c773fe1f
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: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43
result, different first party: Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document.
unsupported: false
passed: true
test failed: false
Failed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
result, different first party:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
75ad195c-7360-4024-acbd-7cc73f3a88da
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
697630c9-dcc2-4455-8a29-27655f87372d,
b0b81741-ce0a-4da9-a847-8546019db2c8
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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f
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:
69e5b0e4-70f8-48e9-9743-0c8924e002e0,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389
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:
e866cb47-f99b-49ef-9363-fff628d0cdf2,
30ed29fc-999b-4192-8147-b8ac04c45a12
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:
02fa9553-d71b-467b-83b5-a138eda6698d,
8730e3a9-f808-4678-bf99-7c0bee79f73c
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: 7938b722-8d2a-43e4-9a9c-5c6862a8801a
result, different first party: null
unsupported: false
passed: true
test failed: false
Passed
write: (secret) => sessionStorage.setItem("secret", secret)
read: () => sessionStorage.getItem("secret")
result, same first party:
e000bc57-a9e3-4fec-a11f-37fae427b3ee,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93
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: 3012f5f3-b088-4785-a968-57354668da41
result, different first party: null
unsupported: false
passed: true
test failed: 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_2da1fdd5-36c0-4191-8232-c0bf6d4e851d,
name_d5c386a0-583d-40fa-b7aa-a9349b12b9e2
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_0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892,
name_3994da5b-a26d-4958-affd-b8e0c773fe1f
result, different first party:
name_0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892,
name_3994da5b-a26d-4958-affd-b8e0c773fe1f
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party: name_61e8444a-3a7e-4dfa-8d0c-c09e12d83c43
result, different first party:
unsupported: false
passed: true
test failed: false
Failed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
name_75ad195c-7360-4024-acbd-7cc73f3a88da
result, different first party:
name_a2d5327e-b7c8-4f90-8d86-b8600eb01f11,
name_75ad195c-7360-4024-acbd-7cc73f3a88da
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_697630c9-dcc2-4455-8a29-27655f87372d,
name_b0b81741-ce0a-4da9-a847-8546019db2c8
result, different first party:
name_697630c9-dcc2-4455-8a29-27655f87372d,
name_b0b81741-ce0a-4da9-a847-8546019db2c8
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da,
name_f4022696-be26-4cb3-b9fb-bf5392cc4b4f
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_69e5b0e4-70f8-48e9-9743-0c8924e002e0,
name_28ee2c4b-77e6-4bb9-b36d-6b87d8223389
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_e866cb47-f99b-49ef-9363-fff628d0cdf2,
name_30ed29fc-999b-4192-8147-b8ac04c45a12
result, different first party:
name_e866cb47-f99b-49ef-9363-fff628d0cdf2,
name_30ed29fc-999b-4192-8147-b8ac04c45a12
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_02fa9553-d71b-467b-83b5-a138eda6698d,
name_8730e3a9-f808-4678-bf99-7c0bee79f73c
result, different first party: ,
unsupported: false, false
passed: true, true
test failed: false, false
Passed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party: name_7938b722-8d2a-43e4-9a9c-5c6862a8801a
result, different first party:
unsupported: false
passed: true
test failed: false
Failed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party:
name_e000bc57-a9e3-4fec-a11f-37fae427b3ee,
name_f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93
result, different first party:
name_e000bc57-a9e3-4fec-a11f-37fae427b3ee,
name_f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => window.name = "name_" + secret
read: () => window.name
result, same first party: name_3012f5f3-b088-4785-a968-57354668da41
result, different first party: name_3012f5f3-b088-4785-a968-57354668da41
unsupported: false
passed: false
test failed: 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
result:
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false
result:
Insecure website loaded,
Insecure website loaded
Passed
passed: true
result: Insecure website never loaded
Failed
passed: false, false
result:
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false
result:
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false
result:
Insecure website loaded,
Insecure website loaded
Passed
passed: true, true
result:
Insecure website never loaded,
Insecure website never loaded
Failed
passed: false, false
result:
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false
result:
Insecure website loaded,
Insecure website loaded
Passed
passed: true
result: Insecure website never loaded
Failed
passed: false, false
result:
Insecure website loaded,
Insecure website loaded
Failed
passed: false
result: 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
passed: true, true
Passed
upgraded: true, true
passed: true, true
Passed
upgraded: true
passed: true
Failed
upgraded: false, false
passed: false, false
Passed
upgraded: true, true
passed: true, true
Failed
upgraded: false, false
passed: false, false
Passed
upgraded: true, true
passed: true, true
Failed
upgraded: false, false
passed: false, false
Failed
upgraded: false, false
passed: false, false
Passed
upgraded: true
passed: true
Passed
upgraded: true, true
passed: true, true
Failed
upgraded: false
passed: 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
passed: true, true
Passed
upgraded: true, true
passed: true, true
Passed
upgraded: true
passed: true
Failed
upgraded: false, false
passed: false, false
Passed
upgraded: true, true
passed: true, true
Failed
upgraded: false, false
passed: false, false
Passed
upgraded: true, true
passed: true, true
Failed
upgraded: false, false
passed: false, false
Passed
upgraded: true, true
passed: true, true
Passed
upgraded: true
passed: true
Passed
upgraded: true, true
passed: true, true
Failed
upgraded: false
passed: 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
result: upgraded, upgraded
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true
result: upgraded
Failed
passed: false, false
result:
loaded insecurely,
loaded insecurely
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true
result: upgraded
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true
result: 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
result: blocked, blocked
Passed
passed: true, true
result: blocked, blocked
Passed
passed: true
result: blocked
Passed
passed: true, true
result: blocked, blocked
Passed
passed: true, true
result: blocked, blocked
Passed
passed: true, true
result: blocked, blocked
Passed
passed: true, true
result: upgraded, upgraded
Passed
passed: true, true
result: blocked, blocked
Passed
passed: true, true
result: blocked, blocked
Passed
passed: true
result: upgraded
Passed
passed: true, true
result: blocked, blocked
Passed
passed: true
result: 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
Passed
SNI_status: encrypted
passed: true, true
Failed
SNI_status: plaintext
passed: false
Failed
SNI_status: plaintext
passed: false, false
Passed
SNI_status: encrypted
passed: true, true
Failed
SNI_status: plaintext
passed: false, false
Failed
SNI_status: plaintext
passed: false, false
Failed
SNI_status: plaintext
passed: false, false
Failed
SNI_status: plaintext
passed: false, false
Failed
SNI_status: plaintext
passed: false
Passed
SNI_status: encrypted
passed: true, true
Passed
SNI_status: encrypted
passed: 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
Failed
header value: undefined
passed: false, false
Passed
header value: 1
passed: true
Passed
header value: 1
passed: true, true
Failed
header value: undefined
passed: false, false
Failed
header value: undefined
passed: false, false
Passed
header value: 1
passed: true, true
Failed
header value: undefined
passed: false, false
Failed
header value: undefined
passed: false, false
Passed
header value: 1
passed: true
Failed
header value: undefined
passed: false, false
Failed
header value: undefined
passed: 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
Failed
passed: false, false
Passed
sec-gpc: 1
passed: true
Failed
passed: false, false
Failed
passed: false, false
Failed
passed: false, false
Passed
sec-gpc: 1
passed: true, true
Failed
passed: false, false
Failed
passed: false, false
Passed
sec-gpc: 1
passed: true
Failed
passed: false, false
Failed
passed: 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
Failed
passed: false, false
Failed
passed: false
Failed
passed: false, false
Failed
passed: false, false
Failed
passed: false, false
Failed
passed: false, false
Failed
passed: false, false
Failed
passed: false, false
Passed
passed: true
Failed
passed: false, false
Failed
passed: 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
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
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
readSameFirstParty: Error: Unsupported
readDifferentFirstParty: Error: Unsupported
testFailed: 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
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
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
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
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
readSameFirstParty:
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported
testFailed: false, false
Passed
write: () => {
      if (!usingTor) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      if (usingTor) {
        return ipAddress;
      } else {
        throw new Error("Unsupported");
      }
    }
unsupported: false
readSameFirstParty: 2001:67c:e60:c0c:192:42:116:194
readDifferentFirstParty: 45.148.10.111
passed: true
testFailed: 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
readSameFirstParty: Error: Unsupported
readDifferentFirstParty: Error: Unsupported
testFailed: 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
passed: false, false
Failed
IsTorExit: false, false
passed: false, false
Failed
IsTorExit: false
passed: false
Failed
IsTorExit: false, false
passed: false, false
Failed
IsTorExit: false, false
passed: false, false
Failed
IsTorExit: false, false
passed: false, false
Failed
IsTorExit: false, false
passed: false, false
Failed
IsTorExit: false, false
passed: false, false
Failed
IsTorExit: false, false
passed: false, false
Passed
IsTorExit: true
passed: true
Failed
IsTorExit: false, false
passed: false, false
Failed
IsTorExit: false
passed: 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').`,
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
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
__hssc
HubSpot tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
__hstc
HubSpot tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
__s
Drip.com email address tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
_hsenc
HubSpot tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
_openstat
Yandex tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
dclid
DoubleClick Click ID (Google)
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
fbclid
Facebook Click Identifier
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
gclid
Google Click Identifier
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
hsCtaTracking
HubSpot tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
mc_eid
Mailchimp Email ID (email recipient's address)
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
mkt_tok
Adobe Marketo tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
ml_subscriber
MailerLite email tracking
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
ml_subscriber_hash
MailerLite email tracking
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
msclkid
Microsoft Click ID
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
oly_anon_id
Omeda marketing 'anonymous' customer id
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
oly_enc_id
Omeda marketing 'known' customer id
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
rb_clickid
Unknown high-entropy tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
s_cid
Adobe Site Catalyst tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
vero_conv
Vero tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
vero_id
Vero tracking parameter
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
wickedid
Wicked Reports e-commerce tracking
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
yclid
Yandex Click ID
Passed
passed: true, true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: false, false
Passed
passed: true
Failed
value: 8061754823985428
passed: false, false
Failed
value: 8061754823985428
passed: 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
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true, true
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true, true
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false
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
Failed
url: https://dpm.demdex.net/ibs
passed: false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false
Passed
url: https://dpm.demdex.net/ibs
passed: true, true
Failed
url: https://dpm.demdex.net/ibs
passed: false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false
Passed
url: https://dpm.demdex.net/ibs
passed: true, true
Failed
url: https://dpm.demdex.net/ibs
passed: false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false
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
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false
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
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true
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
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
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
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
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
Failed
url: https://bat.bing.com/bat.js
passed: false, false
Failed
url: https://bat.bing.com/bat.js
passed: false
Passed
url: https://bat.bing.com/bat.js
passed: true, true
Failed
url: https://bat.bing.com/bat.js
passed: false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false
Passed
url: https://bat.bing.com/bat.js
passed: true, true
Failed
url: https://bat.bing.com/bat.js
passed: false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false
Failed
url: https://bat.bing.com/bat.js
passed: false
Failed
url: https://bat.bing.com/bat.js
passed: false, false
Failed
url: https://bat.bing.com/bat.js
passed: false
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
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true, true
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: 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
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: 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
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: 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
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
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true
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
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true
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
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false
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
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false, false
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true
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
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
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
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
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
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
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true
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
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true
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
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false
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
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true, true
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
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
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
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
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
Failed
url: https://google-analytics.com/urchin.js
passed: false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false
Passed
url: https://google-analytics.com/urchin.js
passed: true, true
Failed
url: https://google-analytics.com/urchin.js
passed: false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false
Passed
url: https://google-analytics.com/urchin.js
passed: true, true
Failed
url: https://google-analytics.com/urchin.js
passed: false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false
Failed
url: https://google-analytics.com/urchin.js
passed: false, false
Failed
url: https://google-analytics.com/urchin.js
passed: false
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
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
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true, true
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
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
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
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
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
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false, false
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true, true
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
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
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
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
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
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
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true
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
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true
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
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false
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
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false
Passed
url: https://pixel.quantserve.com/pixel
passed: true, true
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false
Passed
url: https://pixel.quantserve.com/pixel
passed: true, true
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false
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
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
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true
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
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true
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
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false, false
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: false
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
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
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true, true
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
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true, true
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
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false
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
Failed
url: https://t.co/i/adsct
passed: false, false
Passed
url: https://t.co/i/adsct
passed: true
Passed
url: https://t.co/i/adsct
passed: true, true
Failed
url: https://t.co/i/adsct
passed: false, false
Failed
url: https://t.co/i/adsct
passed: false, false
Passed
url: https://t.co/i/adsct
passed: true, true
Failed
url: https://t.co/i/adsct
passed: false, false
Failed
url: https://t.co/i/adsct
passed: false, false
Failed
url: https://t.co/i/adsct
passed: false
Failed
url: https://t.co/i/adsct
passed: false, false
Failed
url: https://t.co/i/adsct
passed: false
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
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true, true
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
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true, true
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
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
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
result, different session: h2, h2
unsupported: false, false
passed: true, true
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
result, different session: h2, h2
unsupported: false, false
passed: true, true
test failed: false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }
read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }
result, same session: h2
result, different session: h2
unsupported: true
passed: undefined
test failed: false
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
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
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
result, different session: h3, h2
unsupported: false, false
passed: false, true
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
result, different session: h2, h2
unsupported: false, false
passed: true, true
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
result, different session: h2, h2
unsupported: false, false
passed: true, true
test failed: 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
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }
read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }
result, same session: h2
result, different session: h2
unsupported: true
passed: undefined
test failed: false
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
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }
read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }
result, same session: h3
result, different session: h2
unsupported: false
passed: true
test failed: false
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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p,
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p
result, different session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p,
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
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
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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session: 33311936-4cfc-4386-b886-053c3b391c22_1p
result, different session: 33311936-4cfc-4386-b886-053c3b391c22_1p
unsupported: false
passed: false
test failed: false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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
result, different session:
15571fa3-0642-4589-90a9-ec73a7a073d9_1p,
15571fa3-0642-4589-90a9-ec73a7a073d9_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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_1p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_1p
result, different session:
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_1p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_1p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
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
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_1p,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_1p
result, different session:
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
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
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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
a31f089a-366d-46aa-8a3d-39c59eae3ef3_1p,
a31f089a-366d-46aa-8a3d-39c59eae3ef3_1p
result, different session:
a31f089a-366d-46aa-8a3d-39c59eae3ef3_1p,
a31f089a-366d-46aa-8a3d-39c59eae3ef3_1p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session: 7938b722-8d2a-43e4-9a9c-5c6862a8801a_1p
result, different session: Error: cacheKeys[0] is undefined
unsupported: false
passed: true
test failed: false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
1af58a1e-55c5-4125-ba6b-5729d21fd23c_1p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_1p
result, different session:
1af58a1e-55c5-4125-ba6b-5729d21fd23c_1p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_1p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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: 3012f5f3-b088-4785-a968-57354668da41_1p
result, different session: 3012f5f3-b088-4785-a968-57354668da41_1p
unsupported: false
passed: false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p_http,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_1p_http
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_1p_http,
3994da5b-a26d-4958-affd-b8e0c773fe1f_1p_http
result, different session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_1p_http,
3994da5b-a26d-4958-affd-b8e0c773fe1f_1p_http
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43_1p_http
result, different session: null
unsupported: false
passed: true
test failed: false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_1p_http,
75ad195c-7360-4024-acbd-7cc73f3a88da_1p_http
result, different session:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_1p_http,
75ad195c-7360-4024-acbd-7cc73f3a88da_1p_http
unsupported: false, false
passed: false, false
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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
697630c9-dcc2-4455-8a29-27655f87372d_1p_http,
b0b81741-ce0a-4da9-a847-8546019db2c8_1p_http
result, different session:
697630c9-dcc2-4455-8a29-27655f87372d_1p_http,
b0b81741-ce0a-4da9-a847-8546019db2c8_1p_http
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_1p_http,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_1p_http
result, different session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_1p_http,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_1p_http
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_1p_http,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_1p_http
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
e866cb47-f99b-49ef-9363-fff628d0cdf2_1p_http,
30ed29fc-999b-4192-8147-b8ac04c45a12_1p_http
result, different session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_1p_http,
30ed29fc-999b-4192-8147-b8ac04c45a12_1p_http
unsupported: false, false
passed: false, false
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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
02fa9553-d71b-467b-83b5-a138eda6698d_1p_http,
8730e3a9-f808-4678-bf99-7c0bee79f73c_1p_http
result, different session:
02fa9553-d71b-467b-83b5-a138eda6698d_1p_http,
8730e3a9-f808-4678-bf99-7c0bee79f73c_1p_http
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session: 7938b722-8d2a-43e4-9a9c-5c6862a8801a_1p_http
result, different session: null
unsupported: false
passed: true
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_1p_http,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_1p_http
result, different session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_1p_http,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_1p_http
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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: 3012f5f3-b088-4785-a968-57354668da41_1p_http
result, different session: 3012f5f3-b088-4785-a968-57354668da41_1p_http
unsupported: false
passed: false
test failed: 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=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p_js,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_1p_js
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_1p_js,
3994da5b-a26d-4958-affd-b8e0c773fe1f_1p_js
result, different session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_1p_js,
3994da5b-a26d-4958-affd-b8e0c773fe1f_1p_js
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43_1p_js
result, different session: null
unsupported: false
passed: true
test failed: false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_1p_js,
75ad195c-7360-4024-acbd-7cc73f3a88da_1p_js
result, different session:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_1p_js,
75ad195c-7360-4024-acbd-7cc73f3a88da_1p_js
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
697630c9-dcc2-4455-8a29-27655f87372d_1p_js,
b0b81741-ce0a-4da9-a847-8546019db2c8_1p_js
result, different session:
697630c9-dcc2-4455-8a29-27655f87372d_1p_js,
b0b81741-ce0a-4da9-a847-8546019db2c8_1p_js
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_1p_js,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_1p_js
result, different session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_1p_js,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_1p_js
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_1p_js,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_1p_js
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_1p_js,
30ed29fc-999b-4192-8147-b8ac04c45a12_1p_js
result, different session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_1p_js,
30ed29fc-999b-4192-8147-b8ac04c45a12_1p_js
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
02fa9553-d71b-467b-83b5-a138eda6698d_1p_js,
8730e3a9-f808-4678-bf99-7c0bee79f73c_1p_js
result, different session:
02fa9553-d71b-467b-83b5-a138eda6698d_1p_js,
8730e3a9-f808-4678-bf99-7c0bee79f73c_1p_js
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: 7938b722-8d2a-43e4-9a9c-5c6862a8801a_1p_js
result, different session: null
unsupported: false
passed: true
test failed: false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_1p_js,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_1p_js
result, different session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_1p_js,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_1p_js
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: 3012f5f3-b088-4785-a968-57354668da41_1p_js
result, different session: 3012f5f3-b088-4785-a968-57354668da41_1p_js
unsupported: false
passed: false
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_1p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_1p
result, different session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_1p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_1p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }
read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }
result, same session: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43_1p
result, different session: null
unsupported: false
passed: true
test failed: 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:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_1p,
75ad195c-7360-4024-acbd-7cc73f3a88da_1p
result, different session:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_1p,
75ad195c-7360-4024-acbd-7cc73f3a88da_1p
unsupported: false, false
passed: false, false
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:
697630c9-dcc2-4455-8a29-27655f87372d_1p,
b0b81741-ce0a-4da9-a847-8546019db2c8_1p
result, different session:
697630c9-dcc2-4455-8a29-27655f87372d_1p,
b0b81741-ce0a-4da9-a847-8546019db2c8_1p
unsupported: false, false
passed: false, false
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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_1p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_1p
result, different session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_1p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_1p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }
read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_1p,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_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:
e866cb47-f99b-49ef-9363-fff628d0cdf2_1p,
30ed29fc-999b-4192-8147-b8ac04c45a12_1p
result, different session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_1p,
30ed29fc-999b-4192-8147-b8ac04c45a12_1p
unsupported: false, false
passed: false, false
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:
02fa9553-d71b-467b-83b5-a138eda6698d_1p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_1p
result, different session:
02fa9553-d71b-467b-83b5-a138eda6698d_1p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_1p
unsupported: false, false
passed: false, false
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: Error: Unsupported
result, different session: Error: Unsupported
unsupported: true
passed: undefined
test failed: 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:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_1p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_1p
result, different session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_1p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_1p
unsupported: false, false
passed: false, false
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: 3012f5f3-b088-4785-a968-57354668da41_1p
result, different session: 3012f5f3-b088-4785-a968-57354668da41_1p
unsupported: false
passed: false
test failed: 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_2378315372861286,
fake_770166301301773
result, different session:
fake_2378315372861286,
fake_770166301301773
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_3477087821528724,
fake_8210827167735686
result, different session:
fake_3477087821528724,
fake_8210827167735686
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_28448048050223496
result, different session: fake_28448048050223496
unsupported: false
passed: false
test failed: 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_9451558370569058,
fake_8208353266356461
result, different session:
fake_9451558370569058,
fake_8208353266356461
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_39751889086400016,
fake_6810659123072658
result, different session:
fake_39751889086400016,
fake_6810659123072658
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_20907315706056107,
fake_39210623488054175
result, different session:
fake_20907315706056107,
fake_39210623488054175
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }
read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }
result, same session:
fake_12255365816246044,
fake_1046116629565359
result, different session:
fake_5935028647211151,
fake_6725201088517536
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_08971688227465857,
fake_05013054249920468
result, different session:
fake_08971688227465857,
fake_05013054249920468
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_7747741931797041,
fake_8059661257878372
result, different session:
fake_7747741931797041,
fake_8059661257878372
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }
read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }
result, same session: fake_9230115749235901
result, different session: fake_5614466140703915
unsupported: false
passed: true
test failed: 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_9942832757098552,
fake_5851143650663779
result, different session:
fake_9942832757098552,
fake_5851143650663779
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_00028731342212484634
result, different session: fake_00028731342212484634
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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
result, different session:
Error: No requests received,
Error: No requests received
unsupported: true, true
passed: undefined
test failed: 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
result, different session:
Error: No requests received,
Error: No requests received
unsupported: true, true
passed: undefined
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
result, different session: 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 session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_1p
result, different session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_1p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_1p
result, different session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_1p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_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: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43_1p
result, different session: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43_1p
unsupported: false
passed: false
test failed: 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:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_1p,
75ad195c-7360-4024-acbd-7cc73f3a88da_1p
result, different session:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_1p,
75ad195c-7360-4024-acbd-7cc73f3a88da_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:
697630c9-dcc2-4455-8a29-27655f87372d_1p,
b0b81741-ce0a-4da9-a847-8546019db2c8_1p
result, different session:
697630c9-dcc2-4455-8a29-27655f87372d_1p,
b0b81741-ce0a-4da9-a847-8546019db2c8_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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_1p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_1p
result, different session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_1p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_1p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_1p,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_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:
e866cb47-f99b-49ef-9363-fff628d0cdf2_1p,
30ed29fc-999b-4192-8147-b8ac04c45a12_1p
result, different session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_1p,
30ed29fc-999b-4192-8147-b8ac04c45a12_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:
02fa9553-d71b-467b-83b5-a138eda6698d_1p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_1p
result, different session:
02fa9553-d71b-467b-83b5-a138eda6698d_1p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_1p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session: 7938b722-8d2a-43e4-9a9c-5c6862a8801a_1p
result, different session: undefined
unsupported: false
passed: true
test failed: 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:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_1p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_1p
result, different session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_1p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_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: 3012f5f3-b088-4785-a968-57354668da41_1p
result, different session: 3012f5f3-b088-4785-a968-57354668da41_1p
unsupported: false
passed: false
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_1p
result, different session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_1p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_1p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_1p
result, different session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_1p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_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: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43_1p
result, different session: 61e8444a-3a7e-4dfa-8d0c-c09e12d83c43_1p
unsupported: false
passed: false
test failed: false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_1p,
75ad195c-7360-4024-acbd-7cc73f3a88da_1p
result, different session:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_1p,
75ad195c-7360-4024-acbd-7cc73f3a88da_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:
697630c9-dcc2-4455-8a29-27655f87372d_1p,
b0b81741-ce0a-4da9-a847-8546019db2c8_1p
result, different session:
697630c9-dcc2-4455-8a29-27655f87372d_1p,
b0b81741-ce0a-4da9-a847-8546019db2c8_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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_1p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_1p
result, different session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_1p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_1p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_1p,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_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:
e866cb47-f99b-49ef-9363-fff628d0cdf2_1p,
30ed29fc-999b-4192-8147-b8ac04c45a12_1p
result, different session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_1p,
30ed29fc-999b-4192-8147-b8ac04c45a12_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:
02fa9553-d71b-467b-83b5-a138eda6698d_1p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_1p
result, different session:
02fa9553-d71b-467b-83b5-a138eda6698d_1p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_1p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session: 7938b722-8d2a-43e4-9a9c-5c6862a8801a_1p
result, different session: null
unsupported: false
passed: true
test failed: false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_1p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_1p
result, different session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_1p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_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: 3012f5f3-b088-4785-a968-57354668da41_1p
result, different session: 3012f5f3-b088-4785-a968-57354668da41_1p
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1
result, different session: 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 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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: Error: No requests received
result, different session: Error: No requests received
unsupported: true
passed: undefined
test failed: false
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })
read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })
read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
result, different session: h2, h2
unsupported: false, false
passed: true, true
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
result, different session: h2, h2
unsupported: false, false
passed: true, true
test failed: false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }
read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }
result, same session: h2
result, different session: h2
unsupported: true
passed: undefined
test failed: false
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
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
result, different session: h3, h3
unsupported: false, false
passed: false, false
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 session: h3, h3
result, different session: h3, h2
unsupported: false, false
passed: false, true
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
result, different session: h2, h2
unsupported: false, false
passed: true, true
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
result, different session: h2, h2
unsupported: false, false
passed: true, true
test failed: 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
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }
read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }
result, same session: h2
result, different session: h2
unsupported: true
passed: undefined
test failed: false
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
Passed
write: async () => {
      // Clear Alt-Svc caching first.
      let responseText = "";
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/clear");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after clear:", responseText);
      // Store "h3" state in Alt-Svc cache
      for (let i = 0; i < 3; ++i) {
        await fetch(altSvcOrigin + "/set");
        await sleepMs(100);
      }
      responseText = await fetchText(altSvcOrigin + "/protocol");
      console.log("after set:", responseText);
    }
read: async () => {
      const protocol = await fetchText(altSvcOrigin + "/protocol");
      if ((new URL(location)).searchParams.get("thirdparty") === "same") {
        if (protocol !== "h3") {
          throw new Error("Unsupported");
        }
      }
      return protocol;
    }
result, same session: h3
result, different session: h2
unsupported: false
passed: true
test failed: false
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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_3p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_3p
result, different session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_3p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_3p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
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
unsupported: false, false
passed: false, false
test failed: false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.
result, different session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent.
unsupported: true
passed: undefined
test failed: false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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
result, different session:
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p,
1a5b5a6f-5aeb-49ba-8577-c852ce8b48e5_3p
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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_3p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_3p
result, different session:
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_3p,
4aca6bfb-ecb4-47d0-bce6-bb64559cf8a0_3p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
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
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_3p,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_3p
result, different session:
Error: can't access property "url",
cacheKeys[0] is undefined,
Error: can't access property "url",
cacheKeys[0] is undefined
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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:
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
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=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
62cb741f-c8c7-452b-a081-453be7d8a485_3p,
62cb741f-c8c7-452b-a081-453be7d8a485_3p
result, different session:
62cb741f-c8c7-452b-a081-453be7d8a485_3p,
62cb741f-c8c7-452b-a081-453be7d8a485_3p
unsupported: false, false
passed: false, false
test failed: false, false
Unsupported
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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.
result, different session: Error: The operation is insecure.
unsupported: true
passed: undefined
test failed: false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${key}`]);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: async () => {
      let cache = await caches.open("supercookies");
      let cacheKeys = await cache.keys();
      let url = cacheKeys[0].url;
      return (new URL(url)).searchParams.get("key");
    }
result, same session:
1af58a1e-55c5-4125-ba6b-5729d21fd23c_3p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_3p
result, different session:
1af58a1e-55c5-4125-ba6b-5729d21fd23c_3p,
1af58a1e-55c5-4125-ba6b-5729d21fd23c_3p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (key) => {
      try {
        let cache = await caches.open("supercookies");
        cache.addAll([`test.css?key=${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: 3012f5f3-b088-4785-a968-57354668da41_3p
result, different session: 3012f5f3-b088-4785-a968-57354668da41_3p
unsupported: false
passed: false
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_3p_http,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_3p_http
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_3p_http,
3994da5b-a26d-4958-affd-b8e0c773fe1f_3p_http
result, different session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_3p_http,
3994da5b-a26d-4958-affd-b8e0c773fe1f_3p_http
unsupported: false, false
passed: false, false
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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session: null
result, different session: null
unsupported: true
passed: undefined
test failed: false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session: ,
result, different session: ,
unsupported: true, true
passed: undefined
test failed: false, false
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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
697630c9-dcc2-4455-8a29-27655f87372d_3p_http,
b0b81741-ce0a-4da9-a847-8546019db2c8_3p_http
result, different session:
697630c9-dcc2-4455-8a29-27655f87372d_3p_http,
b0b81741-ce0a-4da9-a847-8546019db2c8_3p_http
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_3p_http,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_3p_http
result, different session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_3p_http,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_3p_http
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${baseURI}cookie?secret=${secret}_http`);
    }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
      let response = await fetch(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_3p_http,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_3p_http
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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:
e866cb47-f99b-49ef-9363-fff628d0cdf2_3p_http,
30ed29fc-999b-4192-8147-b8ac04c45a12_3p_http
result, different session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_3p_http,
30ed29fc-999b-4192-8147-b8ac04c45a12_3p_http
unsupported: false, false
passed: false, false
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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
02fa9553-d71b-467b-83b5-a138eda6698d_3p_http,
8730e3a9-f808-4678-bf99-7c0bee79f73c_3p_http
result, different session:
02fa9553-d71b-467b-83b5-a138eda6698d_3p_http,
8730e3a9-f808-4678-bf99-7c0bee79f73c_3p_http
unsupported: false, false
passed: false, false
test failed: false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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: null
result, different session: null
unsupported: true
passed: undefined
test failed: 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(`${baseURI}headers`);
      let cookie = (await response.json())["cookie"];
      return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null;
    }
result, same session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_3p_http,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_3p_http
result, different session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_3p_http,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_3p_http
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
      await fetch(`${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: 3012f5f3-b088-4785-a968-57354668da41_3p_http
result, different session: 3012f5f3-b088-4785-a968-57354668da41_3p_http
unsupported: false
passed: false
test failed: 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=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_3p_js,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_3p_js
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_3p_js,
3994da5b-a26d-4958-affd-b8e0c773fe1f_3p_js
result, different session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_3p_js,
3994da5b-a26d-4958-affd-b8e0c773fe1f_3p_js
unsupported: false, false
passed: false, false
test failed: false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: null
result, different session: null
unsupported: true
passed: undefined
test failed: false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: ,
result, different session: ,
unsupported: true, true
passed: undefined
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
697630c9-dcc2-4455-8a29-27655f87372d_3p_js,
b0b81741-ce0a-4da9-a847-8546019db2c8_3p_js
result, different session:
697630c9-dcc2-4455-8a29-27655f87372d_3p_js,
b0b81741-ce0a-4da9-a847-8546019db2c8_3p_js
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_3p_js,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_3p_js
result, different session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_3p_js,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_3p_js
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_3p_js,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_3p_js
result, different session: ,
unsupported: false, false
passed: true, true
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_3p_js,
30ed29fc-999b-4192-8147-b8ac04c45a12_3p_js
result, different session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_3p_js,
30ed29fc-999b-4192-8147-b8ac04c45a12_3p_js
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
02fa9553-d71b-467b-83b5-a138eda6698d_3p_js,
8730e3a9-f808-4678-bf99-7c0bee79f73c_3p_js
result, different session:
02fa9553-d71b-467b-83b5-a138eda6698d_3p_js,
8730e3a9-f808-4678-bf99-7c0bee79f73c_3p_js
unsupported: false, false
passed: false, false
test failed: false, false
Unsupported
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: null
result, different session: null
unsupported: true
passed: undefined
test failed: false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_3p_js,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_3p_js
result, different session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_3p_js,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_3p_js
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => {
      document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
    }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: 3012f5f3-b088-4785-a968-57354668da41_3p_js
result, different session: 3012f5f3-b088-4785-a968-57354668da41_3p_js
unsupported: false
passed: false
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_3p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_3p
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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_3p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_3p
result, different session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_3p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_3p
unsupported: false, false
passed: false, false
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: null
result, different session: null
unsupported: true
passed: undefined
test failed: false
Unsupported
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }
read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }
result, same session: ,
result, different session: ,
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:
697630c9-dcc2-4455-8a29-27655f87372d_3p,
b0b81741-ce0a-4da9-a847-8546019db2c8_3p
result, different session:
697630c9-dcc2-4455-8a29-27655f87372d_3p,
b0b81741-ce0a-4da9-a847-8546019db2c8_3p
unsupported: false, false
passed: false, false
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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_3p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_3p
result, different session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_3p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_3p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (data) => {
      const msPerHour = 60 * 60 * 1000;
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      window.cookieStore.set({
        name: "partition_test",
        value: data,
        expires: Date.now() + msPerHour,
        sameSite: "none"
      });
    }
read: async () => {
      if (!window.cookieStore) {
        throw new Error("Unsupported");
      }
      const cookie = await window.cookieStore.get("partition_test");
      if (!cookie) {
        return null;
      }
      return cookie.value;
    }
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_3p,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_3p
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:
e866cb47-f99b-49ef-9363-fff628d0cdf2_3p,
30ed29fc-999b-4192-8147-b8ac04c45a12_3p
result, different session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_3p,
30ed29fc-999b-4192-8147-b8ac04c45a12_3p
unsupported: false, false
passed: false, false
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:
02fa9553-d71b-467b-83b5-a138eda6698d_3p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_3p
result, different session:
02fa9553-d71b-467b-83b5-a138eda6698d_3p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_3p
unsupported: false, false
passed: false, false
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: Error: Unsupported
result, different session: Error: Unsupported
unsupported: true
passed: undefined
test failed: 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:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_3p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_3p
result, different session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_3p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_3p
unsupported: false, false
passed: false, false
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: 3012f5f3-b088-4785-a968-57354668da41_3p
result, different session: 3012f5f3-b088-4785-a968-57354668da41_3p
unsupported: false
passed: false
test failed: 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_23850768865580974,
fake_35986165606044374
result, different session:
fake_23850768865580974,
fake_35986165606044374
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_09203927530571887,
fake_2566504401451928
result, different session:
fake_09203927530571887,
fake_2566504401451928
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_3826507311782621
result, different session: fake_3826507311782621
unsupported: false
passed: false
test failed: 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_546431241524572,
fake_7383340077640324
result, different session:
fake_546431241524572,
fake_7383340077640324
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_18987997705855553,
fake_9244454547803365
result, different session:
fake_18987997705855553,
fake_9244454547803365
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_47977407835766006,
fake_8515775258439404
result, different session:
fake_47977407835766006,
fake_8515775258439404
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }
read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }
result, same session:
fake_3523313696076571,
fake_47856269686544484
result, different session:
fake_4129604310040422,
fake_1497856705039693
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_29080099899972955,
fake_5745057591476441
result, different session:
fake_29080099899972955,
fake_5745057591476441
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_3168665942272757,
fake_01880025868048918
result, different session:
fake_3168665942272757,
fake_01880025868048918
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return key;
    }
read: async (key) => {
      const href = testURI("resource", "css", key);
      const head = document.getElementsByTagName("head")[0];
      head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
      const testElement = document.querySelector("#css");
      let fontFamily;
      while (true) {
        await sleepMs(100);
        fontFamily = getComputedStyle(testElement).fontFamily;
        if (fontFamily.startsWith("fake")) {
          break;
        }
      }
      console.log(fontFamily);
      return fontFamily;
    }
result, same session: fake_5119080380427754
result, different session: fake_9257872711282977
unsupported: false
passed: true
test failed: 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_5841631510397598,
fake_4847267951993033
result, different session:
fake_5841631510397598,
fake_4847267951993033
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_5654273831794341
result, different session: fake_5654273831794341
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: 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
result, different session:
Error: No requests received,
Error: No requests received
unsupported: true, true
passed: undefined
test failed: 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
result, different session:
Error: No requests received,
Error: No requests received
unsupported: true, true
passed: undefined
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
result, different session: 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 session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      return key;
    }
read: async (key) => {
      let response = await fetch(testURI("resource", "fetch", key),
                                 {cache: "force-cache"});
      let countResponse = await fetch(testURI("ctr", "fetch", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      return key;
    }
read: async (key) => {
      const text = document.createElement("span");
      text.id = "text";
      text.innerText = "test";
      document.body.appendChild(text);
      const originalWidth = text.getBoundingClientRect().width;
      let style = document.createElement("style");
      style.type='text/css';
      let fontURI = testURI("resource", "font", key);
      style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`;
      document.getElementsByTagName("head")[0].appendChild(style);
      let newWidth;
      do {
        await sleepMs(100);
        newWidth = text.getBoundingClientRect().width;
      } while (newWidth < 0 || newWidth === originalWidth)
      let response = await fetch(
        testURI("ctr", "font", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      iframe.addEventListener("load", () => resolve(key), {once: true});
      iframe.src = testURI("resource", "page", key);
    })
read: async (key) => {
      let iframe = document.createElement("iframe");
      document.body.appendChild(iframe);
      let iframeLoadPromise = new Promise((resolve, reject) => {
        iframe.addEventListener("load", resolve, {once: true});
      });
      let address = testURI("resource", "page", key);
      iframe.src = address;
      await iframeLoadPromise;
      let response = await fetch(
        testURI("ctr", "page", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      img.addEventListener("load", () => resolve(key), {once: true});
      img.src = testURI("resource", "image", key);
    })
read: async (key) => {
      let img = document.createElement("img");
      document.body.appendChild(img);
      let imgLoadPromise = new Promise((resolve, reject) => {
        img.addEventListener("load", resolve, {once: true});
      });
      img.src = testURI("resource", "image", key);
      await imgLoadPromise;
      let response = await fetch(
        testURI("ctr", "image", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_3p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_3p
result, different session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_3p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_3p
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:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_3p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_3p
result, different session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_3p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_3p
unsupported: false, false
passed: false, false
test failed: 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.
result, different session: Error: The user denied permission to access the database.
unsupported: true
passed: undefined
test failed: 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:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_3p,
75ad195c-7360-4024-acbd-7cc73f3a88da_3p
result, different session:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_3p,
75ad195c-7360-4024-acbd-7cc73f3a88da_3p
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:
697630c9-dcc2-4455-8a29-27655f87372d_3p,
b0b81741-ce0a-4da9-a847-8546019db2c8_3p
result, different session:
697630c9-dcc2-4455-8a29-27655f87372d_3p,
b0b81741-ce0a-4da9-a847-8546019db2c8_3p
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:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_3p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_3p
result, different session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_3p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_3p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (secret) => {
      try {
        return await IdbKeyVal.set("secret", secret);
      } catch (e) {
        throw new Error("Unsupported");
      }
    }
read: () => IdbKeyVal.get("secret")
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_3p,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_3p
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:
e866cb47-f99b-49ef-9363-fff628d0cdf2_3p,
30ed29fc-999b-4192-8147-b8ac04c45a12_3p
result, different session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_3p,
30ed29fc-999b-4192-8147-b8ac04c45a12_3p
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:
02fa9553-d71b-467b-83b5-a138eda6698d_3p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_3p
result, different session:
02fa9553-d71b-467b-83b5-a138eda6698d_3p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_3p
unsupported: false, false
passed: false, false
test failed: 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
result, different session: Error: IDBFactory.open: The operation is insecure
unsupported: true
passed: undefined
test failed: 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:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_3p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_3p
result, different session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_3p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_3p
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: 3012f5f3-b088-4785-a968-57354668da41_3p
result, different session: 3012f5f3-b088-4785-a968-57354668da41_3p
unsupported: false
passed: false
test failed: 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:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_3p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_3p
result, different session:
2da1fdd5-36c0-4191-8232-c0bf6d4e851d_3p,
d5c386a0-583d-40fa-b7aa-a9349b12b9e2_3p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_3p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_3p
result, different session:
0ff2bd5a-2bb6-4174-a8c5-6e7f6264d892_3p,
3994da5b-a26d-4958-affd-b8e0c773fe1f_3p
unsupported: false, false
passed: false, false
test failed: 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.
result, different session: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.
unsupported: true
passed: undefined
test failed: false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_3p,
75ad195c-7360-4024-acbd-7cc73f3a88da_3p
result, different session:
a2d5327e-b7c8-4f90-8d86-b8600eb01f11_3p,
75ad195c-7360-4024-acbd-7cc73f3a88da_3p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
697630c9-dcc2-4455-8a29-27655f87372d_3p,
b0b81741-ce0a-4da9-a847-8546019db2c8_3p
result, different session:
697630c9-dcc2-4455-8a29-27655f87372d_3p,
b0b81741-ce0a-4da9-a847-8546019db2c8_3p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_3p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_3p
result, different session:
d166ad6c-f357-4e02-a3c2-5ecc7a6ae1da_3p,
f4022696-be26-4cb3-b9fb-bf5392cc4b4f_3p
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
69e5b0e4-70f8-48e9-9743-0c8924e002e0_3p,
28ee2c4b-77e6-4bb9-b36d-6b87d8223389_3p
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:
e866cb47-f99b-49ef-9363-fff628d0cdf2_3p,
30ed29fc-999b-4192-8147-b8ac04c45a12_3p
result, different session:
e866cb47-f99b-49ef-9363-fff628d0cdf2_3p,
30ed29fc-999b-4192-8147-b8ac04c45a12_3p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
02fa9553-d71b-467b-83b5-a138eda6698d_3p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_3p
result, different session:
02fa9553-d71b-467b-83b5-a138eda6698d_3p,
8730e3a9-f808-4678-bf99-7c0bee79f73c_3p
unsupported: false, false
passed: false, false
test failed: false, false
Unsupported
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session: Error: The operation is insecure.
result, different session: Error: The operation is insecure.
unsupported: true
passed: undefined
test failed: false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_3p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_3p
result, different session:
e000bc57-a9e3-4fec-a11f-37fae427b3ee_3p,
f9df8d4b-5ff1-4cdf-9f72-8b60cee90c93_3p
unsupported: false, false
passed: false, false
test failed: false, false
Failed
write: (secret) => localStorage.setItem("secret", secret)
read: () => localStorage.getItem("secret")
result, same session: 3012f5f3-b088-4785-a968-57354668da41_3p
result, different session: 3012f5f3-b088-4785-a968-57354668da41_3p
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: 1, 1
result, different session: 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 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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Unsupported
write: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      return key;
    }
read: async (key) => {
      let link = document.createElement("link");
      link.rel = "prefetch";
      link.href = testURI("resource", "prefetch", key);
      document.getElementsByTagName("head")[0].appendChild(link);
      await sleepMs(500);
      let response = await fetch(
        testURI("ctr", "prefetch", key), {"cache": "reload"});
      let countString = (await response.text()).trim();
      if (parseInt(countString) === 0) {
        throw new Error("No requests received");
      }
      return countString;
    }
result, same session: Error: No requests received
result, different session: Error: No requests received
unsupported: true
passed: undefined
test failed: false
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })
read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: (key) => new Promise((resolve, reject) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      script.addEventListener("load", () => resolve(key), {once: true});
      script.src = testURI("resource", "script", key);
    })
read: async (key) => {
      let script = document.createElement("script");
      document.body.appendChild(script);
      let scriptLoadPromise = new Promise((resolve, reject) => {
        script.addEventListener("load", resolve, {once: true});
      });
      script.src = testURI("resource", "script", key);
      await scriptLoadPromise;
      let response = await fetch(
        testURI("ctr", "script", key), {"cache": "reload"});
      return (await response.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
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
result, different session: 1
unsupported: false
passed: false
test failed: 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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1, 1
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
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
result, different session: 1, 1
unsupported: false, false
passed: false, false
test failed: false, false
Passed
write: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      return key;
    }
read: async (key) => {
      const req = new XMLHttpRequest();
      const loadPromise = new Promise(resolve => req.addEventListener("load", resolve));
      req.open("GET", testURI("resource", "xhr", key));
      req.send();
      await loadPromise;
      let countResponse = await fetch(testURI("ctr", "xhr", key),
                                      {cache: "reload"});
      return (await countResponse.text()).trim();
    }
result, same session: 1
result, different session: 2
unsupported: false
passed: true
test failed: 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
result, different session: 1
unsupported: false
passed: false
test failed: false