iOS Browsers

(default settings)
brave logo
brave
1.93
chrome logo
chrome
152.7977
duckduckgo logo
duckduckgo
7.235
edge logo
edge
152.4191
firefox logo
firefox
155.0
focus logo
focus
155.0
safari logo
safari
26.6
vivaldi logo
vivaldi
8.4098
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same first party: h3, Error: Unsupported, h3, Error: Unsupported, h3
result, different first party: h2, h2, h2, h2, h2
unsupported: false, true, false, true, false
passed: true, true, true
test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same first party: h3, Error: Unsupported, h3, Error: Unsupported, h3
result, different first party: h2, h2, h2, h2, h2
unsupported: false, true, false, true, false
passed: true, true, true
test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same first party: h3, Error: Unsupported, h3, Error: Unsupported, h3
result, different first party: h2, h2, h2, h2, h2
unsupported: false, true, false, true, false
passed: true, true, true
test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
h3,
Error: Unsupported,
h3
result, different first party: h2, h2, h2, h2, h2
unsupported: true, true, false, true, false
passed: , true, true
test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same first party: h3, Error: Unsupported, h3, Error: Unsupported, h3
result, different first party: h2, h2, h2, h2, h2
unsupported: false, true, false, true, false
passed: true, true, true
test failed: false, false, false, false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party: h2, h2, h2, h2, h2
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same first party:
Error: Unsupported,
h3,
Error: Unsupported,
h3,
Error: Unsupported
result, different first party: h2, h2, h2, h2, h2
unsupported: true, false, true, false, true
passed: , true, true
test failed: false, false, false, false, false
Passed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same first party: h3, Error: Unsupported, h3, Error: Unsupported, h3
result, different first party: h2, h2, h2, h2, h2
unsupported: false, true, false, true, false
passed: true, true, true
test failed: false, false, false, false, false
blob
A 'blob URL' is a local reference to some raw data. Trackers can use a blob URL to share data between websites.
Passed
write: (secret) => {
        try {
          const blobURL = URL.createObjectURL(new Blob([secret]));
          fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async (secret) => {
        const response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
        const result = await response.json();
        const blobUrl = decodeURIComponent(result.blobUrl);
        const blobResponse = await fetch(blobUrl);
        return blobResponse.text();
      }
result, same first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
result, different first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const blobURL = URL.createObjectURL(new Blob([secret]));
          fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async (secret) => {
        const response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
        const result = await response.json();
        const blobUrl = decodeURIComponent(result.blobUrl);
        const blobResponse = await fetch(blobUrl);
        return blobResponse.text();
      }
result, same first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
result, different first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const blobURL = URL.createObjectURL(new Blob([secret]));
          fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async (secret) => {
        const response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
        const result = await response.json();
        const blobUrl = decodeURIComponent(result.blobUrl);
        const blobResponse = await fetch(blobUrl);
        return blobResponse.text();
      }
result, same first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
result, different first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const blobURL = URL.createObjectURL(new Blob([secret]));
          fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async (secret) => {
        const response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
        const result = await response.json();
        const blobUrl = decodeURIComponent(result.blobUrl);
        const blobResponse = await fetch(blobUrl);
        return blobResponse.text();
      }
result, same first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
result, different first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const blobURL = URL.createObjectURL(new Blob([secret]));
          fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async (secret) => {
        const response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
        const result = await response.json();
        const blobUrl = decodeURIComponent(result.blobUrl);
        const blobResponse = await fetch(blobUrl);
        return blobResponse.text();
      }
result, same first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
result, different first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const blobURL = URL.createObjectURL(new Blob([secret]));
          fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async (secret) => {
        const response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
        const result = await response.json();
        const blobUrl = decodeURIComponent(result.blobUrl);
        const blobResponse = await fetch(blobUrl);
        return blobResponse.text();
      }
result, same first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
result, different first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const blobURL = URL.createObjectURL(new Blob([secret]));
          fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async (secret) => {
        const response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
        const result = await response.json();
        const blobUrl = decodeURIComponent(result.blobUrl);
        const blobResponse = await fetch(blobUrl);
        return blobResponse.text();
      }
result, same first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
result, different first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const blobURL = URL.createObjectURL(new Blob([secret]));
          fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async (secret) => {
        const response = await fetch(`${baseURI}blob?mode=read&key=${secret}`);
        const result = await response.json();
        const blobUrl = decodeURIComponent(result.blobUrl);
        const blobResponse = await fetch(blobUrl);
        return blobResponse.text();
      }
result, same first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
result, different first party:
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed,
Error: Load failed
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
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 {
          const 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) => {
          const bc = new BroadcastChannel('secrets');
          bc.onmessage = (event) => {
            if (event.data !== 'request') {
              resolve(event.data);
            }
          };
          bc.postMessage('request');
          setTimeout(() => reject(new Error('no BroadcastChannel message')), 3000);
        })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const 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) => {
          const bc = new BroadcastChannel('secrets');
          bc.onmessage = (event) => {
            if (event.data !== 'request') {
              resolve(event.data);
            }
          };
          bc.postMessage('request');
          setTimeout(() => reject(new Error('no BroadcastChannel message')), 3000);
        })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const 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) => {
          const bc = new BroadcastChannel('secrets');
          bc.onmessage = (event) => {
            if (event.data !== 'request') {
              resolve(event.data);
            }
          };
          bc.postMessage('request');
          setTimeout(() => reject(new Error('no BroadcastChannel message')), 3000);
        })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const 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) => {
          const bc = new BroadcastChannel('secrets');
          bc.onmessage = (event) => {
            if (event.data !== 'request') {
              resolve(event.data);
            }
          };
          bc.postMessage('request');
          setTimeout(() => reject(new Error('no BroadcastChannel message')), 3000);
        })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const 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) => {
          const bc = new BroadcastChannel('secrets');
          bc.onmessage = (event) => {
            if (event.data !== 'request') {
              resolve(event.data);
            }
          };
          bc.postMessage('request');
          setTimeout(() => reject(new Error('no BroadcastChannel message')), 3000);
        })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const 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) => {
          const bc = new BroadcastChannel('secrets');
          bc.onmessage = (event) => {
            if (event.data !== 'request') {
              resolve(event.data);
            }
          };
          bc.postMessage('request');
          setTimeout(() => reject(new Error('no BroadcastChannel message')), 3000);
        })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const 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) => {
          const bc = new BroadcastChannel('secrets');
          bc.onmessage = (event) => {
            if (event.data !== 'request') {
              resolve(event.data);
            }
          };
          bc.postMessage('request');
          setTimeout(() => reject(new Error('no BroadcastChannel message')), 3000);
        })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: (secret) => {
        try {
          const 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) => {
          const bc = new BroadcastChannel('secrets');
          bc.onmessage = (event) => {
            if (event.data !== 'request') {
              resolve(event.data);
            }
          };
          bc.postMessage('request');
          setTimeout(() => reject(new Error('no BroadcastChannel message')), 3000);
        })
result, same first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
result, different first party:
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message,
Error: no BroadcastChannel message
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
CacheStorage
The Cache API is a content storage mechanism originally introduced to support ServiceWorkers. If the same Cache object is accessible to multiple websites, it can be abused to track users.
Passed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same first party:
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56
result, different first party:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same first party:
3896d4ce-c55d-4bf1-ae02-9cee2145850c,
3896d4ce-c55d-4bf1-ae02-9cee2145850c,
3896d4ce-c55d-4bf1-ae02-9cee2145850c,
3896d4ce-c55d-4bf1-ae02-9cee2145850c,
3896d4ce-c55d-4bf1-ae02-9cee2145850c
result, different first party:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same first party:
5f0f614c-43fc-420e-944b-4f0a0da990bf,
5f0f614c-43fc-420e-944b-4f0a0da990bf,
5f0f614c-43fc-420e-944b-4f0a0da990bf,
5f0f614c-43fc-420e-944b-4f0a0da990bf,
5f0f614c-43fc-420e-944b-4f0a0da990bf
result, different first party:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same first party:
c30feb74-0688-4e93-a1ee-945a342e2e51,
c30feb74-0688-4e93-a1ee-945a342e2e51,
c30feb74-0688-4e93-a1ee-945a342e2e51,
c30feb74-0688-4e93-a1ee-945a342e2e51,
c30feb74-0688-4e93-a1ee-945a342e2e51
result, different first party:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same first party:
a3efc9cf-e003-4db6-b541-110fd75a7184,
a3efc9cf-e003-4db6-b541-110fd75a7184,
a3efc9cf-e003-4db6-b541-110fd75a7184,
a3efc9cf-e003-4db6-b541-110fd75a7184,
a3efc9cf-e003-4db6-b541-110fd75a7184
result, different first party:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same first party:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
result, different first party:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same first party:
4301548a-9fe6-46c1-bab3-6eca1e419c61,
4301548a-9fe6-46c1-bab3-6eca1e419c61,
4301548a-9fe6-46c1-bab3-6eca1e419c61,
4301548a-9fe6-46c1-bab3-6eca1e419c61,
4301548a-9fe6-46c1-bab3-6eca1e419c61
result, different first party:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same first party:
e2799d44-532c-43fe-aee3-305e020ebb55,
e2799d44-532c-43fe-aee3-305e020ebb55,
e2799d44-532c-43fe-aee3-305e020ebb55,
e2799d44-532c-43fe-aee3-305e020ebb55,
e2799d44-532c-43fe-aee3-305e020ebb55
result, different first party:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
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.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same first party:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_http,
c2a5940f-425e-422d-94f9-135afd1fa5ea_http,
57cd9660-8597-4dd5-8ead-d9990f4ed669_http,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_http,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_http
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same first party:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_http,
95b5d526-459c-4275-9c03-8eaab6524d00_http,
b94f8b75-f692-4a74-be67-2d129ee968fa_http,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_http,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_http
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same first party:
671d85f5-2fe2-4980-b513-c2f951b1388f_http,
19f09c1b-70dc-49ff-89db-7b0581136a7f_http,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_http,
ffce8953-f69a-4566-9acb-9eafce986a0e_http,
f68151b8-82c0-4851-9c11-5e979d40d969_http
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same first party:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_http,
c50594c9-46ea-4084-a075-e3dd6f8cefff_http,
374de0a5-76f5-453d-a8e7-6381fc3a060e_http,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_http,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_http
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same first party:
500f9151-21f8-4127-8879-e18e11248a6f_http,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_http,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_http,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_http,
3e929897-9320-4cef-a12a-6563e2c86cb2_http
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same first party:
69cadac6-f50d-4990-8e84-00bb2148b1b4_http,
e2db4657-3148-411b-aa92-1013549daecf_http,
840f0ae2-df03-4b37-bb48-b3bda8ac4698_http,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27_http,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba_http
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same first party:
aa3860ea-4a49-454f-8472-b9de28cf07b4_http,
0f6f042c-429c-4cee-8107-0fe99108f4a8_http,
860ce808-4495-4d78-a786-45a79cec9a0e_http,
38791220-517f-458a-90fd-65a0b062aa0a_http,
86c36e81-5851-4074-b515-aed4262a971d_http
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same first party:
d25496fb-946c-4b2c-918c-c34c3ef0213a_http,
49ecc7f2-486e-4ab7-a832-addb6a421887_http,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_http,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_http,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_http
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
cookie (JS)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
Passed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_js,
c2a5940f-425e-422d-94f9-135afd1fa5ea_js,
57cd9660-8597-4dd5-8ead-d9990f4ed669_js,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_js,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_js
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_js,
95b5d526-459c-4275-9c03-8eaab6524d00_js,
b94f8b75-f692-4a74-be67-2d129ee968fa_js,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_js,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_js
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
671d85f5-2fe2-4980-b513-c2f951b1388f_js,
19f09c1b-70dc-49ff-89db-7b0581136a7f_js,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_js,
ffce8953-f69a-4566-9acb-9eafce986a0e_js,
f68151b8-82c0-4851-9c11-5e979d40d969_js
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_js,
c50594c9-46ea-4084-a075-e3dd6f8cefff_js,
374de0a5-76f5-453d-a8e7-6381fc3a060e_js,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_js,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_js
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
500f9151-21f8-4127-8879-e18e11248a6f_js,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_js,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_js,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_js,
3e929897-9320-4cef-a12a-6563e2c86cb2_js
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
69cadac6-f50d-4990-8e84-00bb2148b1b4_js,
e2db4657-3148-411b-aa92-1013549daecf_js,
840f0ae2-df03-4b37-bb48-b3bda8ac4698_js,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27_js,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba_js
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
aa3860ea-4a49-454f-8472-b9de28cf07b4_js,
0f6f042c-429c-4cee-8107-0fe99108f4a8_js,
860ce808-4495-4d78-a786-45a79cec9a0e_js,
38791220-517f-458a-90fd-65a0b062aa0a_js,
86c36e81-5851-4074-b515-aed4262a971d_js
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same first party:
d25496fb-946c-4b2c-918c-c34c3ef0213a_js,
49ecc7f2-486e-4ab7-a832-addb6a421887_js,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_js,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_js,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_js
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
CookieStore
The Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.
Passed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same first party:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9,
c2a5940f-425e-422d-94f9-135afd1fa5ea,
57cd9660-8597-4dd5-8ead-d9990f4ed669,
7a2fd1a9-5514-426a-9836-5d3de3ede32e,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same first party:
baef3f1a-5eb8-4825-84b3-1a351cd4f946,
95b5d526-459c-4275-9c03-8eaab6524d00,
b94f8b75-f692-4a74-be67-2d129ee968fa,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same first party:
671d85f5-2fe2-4980-b513-c2f951b1388f,
19f09c1b-70dc-49ff-89db-7b0581136a7f,
46e1edd3-9d95-48b2-95d2-72f092fd6a60,
ffce8953-f69a-4566-9acb-9eafce986a0e,
f68151b8-82c0-4851-9c11-5e979d40d969
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same first party:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c,
c50594c9-46ea-4084-a075-e3dd6f8cefff,
374de0a5-76f5-453d-a8e7-6381fc3a060e,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1,
1f02f498-5031-4d2b-95bb-15e87a1e27dd
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same first party:
500f9151-21f8-4127-8879-e18e11248a6f,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f,
e2a80b15-91bb-43cd-b500-f80f6abd55f8,
d62ff542-078b-452c-a3f0-eb1b0b4b8247,
3e929897-9320-4cef-a12a-6563e2c86cb2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same first party:
69cadac6-f50d-4990-8e84-00bb2148b1b4,
e2db4657-3148-411b-aa92-1013549daecf,
840f0ae2-df03-4b37-bb48-b3bda8ac4698,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same first party:
aa3860ea-4a49-454f-8472-b9de28cf07b4,
0f6f042c-429c-4cee-8107-0fe99108f4a8,
860ce808-4495-4d78-a786-45a79cec9a0e,
38791220-517f-458a-90fd-65a0b062aa0a,
86c36e81-5851-4074-b515-aed4262a971d
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same first party:
d25496fb-946c-4b2c-918c-c34c3ef0213a,
49ecc7f2-486e-4ab7-a832-addb6a421887,
019595da-6f6c-41ef-b1f1-2fc0aece4fec,
691eb37e-8f1e-4fa1-a652-69d8928d3cec,
00c1f48b-e6be-47b9-9c44-dd5281945dc2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
CSS cache
CSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.
Passed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same first party:
fake_7377566990726778,
fake_4225171035223676,
fake_3203792334808102,
fake_6462902440415594,
fake_848232318982298
result, different first party:
fake_6778630226323665,
fake_6910395320001281,
fake_2433550283705812,
fake_6794388289193454,
fake_27422435767467324
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same first party:
fake_2121641915959669,
fake_4465120513135852,
fake_5023769312156414,
fake_7080657679183686,
fake_24631677896452175
result, different first party:
fake_04215237708863473,
fake_41331383152206036,
fake_8302412476248442,
fake_22023967999919658,
fake_909212954732562
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same first party:
fake_1699958275517146,
fake_1429219389877887,
fake_23099109744828739,
fake_923409367816433,
fake_6908598131763937
result, different first party:
fake_7077167205193575,
fake_4027577285768118,
fake_11249342121973993,
fake_12942181500528038,
fake_8271758362875017
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same first party:
fake_35075334009626613,
fake_82834581746787,
fake_5527913468998427,
fake_4015731061323513,
fake_09030583749515242
result, different first party:
fake_049260791725181496,
fake_08173084164090794,
fake_23069791476756318,
fake_7816359847684105,
fake_13447629784039705
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same first party:
fake_3011753716155259,
fake_31488332532010843,
fake_13990694630077383,
fake_9932283317400208,
fake_007672084014407998
result, different first party:
fake_7581408506932943,
fake_8664587490791456,
fake_6234937664259286,
fake_8749409762377358,
fake_3951580313981502
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same first party:
fake_9812933634877938,
fake_5357188922494067,
fake_30664953711150367,
fake_09753394713983488,
fake_5179240424972678
result, different first party:
fake_9067620311473283,
fake_2118462870974771,
fake_48960744985118976,
fake_29584425795154745,
fake_0701442677698898
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same first party:
fake_6993949989374957,
fake_22611346824132905,
fake_7214142428487895,
fake_8660173367185491,
fake_9398374109422452
result, different first party:
fake_906037971710308,
fake_24000112527431505,
fake_8468648350993107,
fake_1785046006061033,
fake_7334684666749804
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same first party:
fake_24587851518939785,
fake_7707197095009946,
fake_02318387454740667,
fake_3315637842167809,
fake_08767867707975463
result, different first party:
fake_4436653573050602,
fake_6599633228870758,
fake_8650371093689242,
fake_47578861801325134,
fake_7780554354845861
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
favicon cache
A favicon is an icon that represents a website, typically shown in browser tab and bookmarks menu. If the favicon cache is not partitioned, it can be used to track users across websites.
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Unsupported
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Unsupported
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Passed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
fetch cache
When a resource is received via the Fetch API, it is frequently cached. That cache can potentially be abused for cross-site tracking.
Passed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 2, 2, 2, 2, 2
result, different first party: 3, 3, 3, 3, 3
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
font cache
Web fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.
Passed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
getDirectory
navigator.storage.getDirectory exposes a location for storing files to web content. In some cases, these files may be shared across tabs.
Passed
write: async (secret) => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt', { create: true });
          const stream = await fileHandle.createWritable();
          await stream.write(secret);
          await stream.close();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt');
          const file = await fileHandle.getFile();
          return file.text();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
result, same first party:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9,
c2a5940f-425e-422d-94f9-135afd1fa5ea,
57cd9660-8597-4dd5-8ead-d9990f4ed669,
7a2fd1a9-5514-426a-9836-5d3de3ede32e,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt', { create: true });
          const stream = await fileHandle.createWritable();
          await stream.write(secret);
          await stream.close();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt');
          const file = await fileHandle.getFile();
          return file.text();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
result, same first party:
baef3f1a-5eb8-4825-84b3-1a351cd4f946,
95b5d526-459c-4275-9c03-8eaab6524d00,
b94f8b75-f692-4a74-be67-2d129ee968fa,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt', { create: true });
          const stream = await fileHandle.createWritable();
          await stream.write(secret);
          await stream.close();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt');
          const file = await fileHandle.getFile();
          return file.text();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
result, same first party:
671d85f5-2fe2-4980-b513-c2f951b1388f,
19f09c1b-70dc-49ff-89db-7b0581136a7f,
46e1edd3-9d95-48b2-95d2-72f092fd6a60,
ffce8953-f69a-4566-9acb-9eafce986a0e,
f68151b8-82c0-4851-9c11-5e979d40d969
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt', { create: true });
          const stream = await fileHandle.createWritable();
          await stream.write(secret);
          await stream.close();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt');
          const file = await fileHandle.getFile();
          return file.text();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
result, same first party:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c,
c50594c9-46ea-4084-a075-e3dd6f8cefff,
374de0a5-76f5-453d-a8e7-6381fc3a060e,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1,
1f02f498-5031-4d2b-95bb-15e87a1e27dd
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt', { create: true });
          const stream = await fileHandle.createWritable();
          await stream.write(secret);
          await stream.close();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt');
          const file = await fileHandle.getFile();
          return file.text();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
result, same first party:
500f9151-21f8-4127-8879-e18e11248a6f,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f,
e2a80b15-91bb-43cd-b500-f80f6abd55f8,
d62ff542-078b-452c-a3f0-eb1b0b4b8247,
3e929897-9320-4cef-a12a-6563e2c86cb2
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt', { create: true });
          const stream = await fileHandle.createWritable();
          await stream.write(secret);
          await stream.close();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt');
          const file = await fileHandle.getFile();
          return file.text();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt', { create: true });
          const stream = await fileHandle.createWritable();
          await stream.write(secret);
          await stream.close();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt');
          const file = await fileHandle.getFile();
          return file.text();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
result, same first party:
aa3860ea-4a49-454f-8472-b9de28cf07b4,
0f6f042c-429c-4cee-8107-0fe99108f4a8,
860ce808-4495-4d78-a786-45a79cec9a0e,
38791220-517f-458a-90fd-65a0b062aa0a,
86c36e81-5851-4074-b515-aed4262a971d
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt', { create: true });
          const stream = await fileHandle.createWritable();
          await stream.write(secret);
          await stream.close();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        try {
          const root = await navigator.storage.getDirectory();
          const fileHandle = await root.getFileHandle('secret.txt');
          const file = await fileHandle.getFile();
          return file.text();
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
result, same first party:
d25496fb-946c-4b2c-918c-c34c3ef0213a,
49ecc7f2-486e-4ab7-a832-addb6a421887,
019595da-6f6c-41ef-b1f1-2fc0aece4fec,
691eb37e-8f1e-4fa1-a652-69d8928d3cec,
00c1f48b-e6be-47b9-9c44-dd5281945dc2
result, different first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
H1 connection
HTTP/1.x are the classic web connection protocols. If these connections are re-used across websites, they can be used to track users.
Passed
write: async (secret) => {
        await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h1.privacytests2.org:8901/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9,
c2a5940f-425e-422d-94f9-135afd1fa5ea,
57cd9660-8597-4dd5-8ead-d9990f4ed669,
7a2fd1a9-5514-426a-9836-5d3de3ede32e,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h1.privacytests2.org:8901/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party: , , , ,
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: async (secret) => {
        await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h1.privacytests2.org:8901/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
671d85f5-2fe2-4980-b513-c2f951b1388f,
19f09c1b-70dc-49ff-89db-7b0581136a7f,
46e1edd3-9d95-48b2-95d2-72f092fd6a60,
ffce8953-f69a-4566-9acb-9eafce986a0e,
f68151b8-82c0-4851-9c11-5e979d40d969
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h1.privacytests2.org:8901/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party: , , , ,
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: async (secret) => {
        await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h1.privacytests2.org:8901/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
500f9151-21f8-4127-8879-e18e11248a6f,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f,
e2a80b15-91bb-43cd-b500-f80f6abd55f8,
d62ff542-078b-452c-a3f0-eb1b0b4b8247,
3e929897-9320-4cef-a12a-6563e2c86cb2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h1.privacytests2.org:8901/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
69cadac6-f50d-4990-8e84-00bb2148b1b4,
e2db4657-3148-411b-aa92-1013549daecf,
840f0ae2-df03-4b37-bb48-b3bda8ac4698,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h1.privacytests2.org:8901/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
aa3860ea-4a49-454f-8472-b9de28cf07b4,
0f6f042c-429c-4cee-8107-0fe99108f4a8,
860ce808-4495-4d78-a786-45a79cec9a0e,
38791220-517f-458a-90fd-65a0b062aa0a,
86c36e81-5851-4074-b515-aed4262a971d
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h1.privacytests2.org:8901/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party: , , , ,
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
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=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h2.privacytests2.org:8902/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9,
c2a5940f-425e-422d-94f9-135afd1fa5ea,
57cd9660-8597-4dd5-8ead-d9990f4ed669,
7a2fd1a9-5514-426a-9836-5d3de3ede32e,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h2.privacytests2.org:8902/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
baef3f1a-5eb8-4825-84b3-1a351cd4f946,
95b5d526-459c-4275-9c03-8eaab6524d00,
b94f8b75-f692-4a74-be67-2d129ee968fa,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h2.privacytests2.org:8902/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
671d85f5-2fe2-4980-b513-c2f951b1388f,
19f09c1b-70dc-49ff-89db-7b0581136a7f,
46e1edd3-9d95-48b2-95d2-72f092fd6a60,
ffce8953-f69a-4566-9acb-9eafce986a0e,
f68151b8-82c0-4851-9c11-5e979d40d969
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h2.privacytests2.org:8902/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c,
c50594c9-46ea-4084-a075-e3dd6f8cefff,
374de0a5-76f5-453d-a8e7-6381fc3a060e,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1,
1f02f498-5031-4d2b-95bb-15e87a1e27dd
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h2.privacytests2.org:8902/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
500f9151-21f8-4127-8879-e18e11248a6f,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f,
e2a80b15-91bb-43cd-b500-f80f6abd55f8,
d62ff542-078b-452c-a3f0-eb1b0b4b8247,
3e929897-9320-4cef-a12a-6563e2c86cb2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h2.privacytests2.org:8902/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
69cadac6-f50d-4990-8e84-00bb2148b1b4,
e2db4657-3148-411b-aa92-1013549daecf,
840f0ae2-df03-4b37-bb48-b3bda8ac4698,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h2.privacytests2.org:8902/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
aa3860ea-4a49-454f-8472-b9de28cf07b4,
0f6f042c-429c-4cee-8107-0fe99108f4a8,
860ce808-4495-4d78-a786-45a79cec9a0e,
38791220-517f-458a-90fd-65a0b062aa0a,
86c36e81-5851-4074-b515-aed4262a971d
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, { cache: 'no-store' });
      }
read: async () => {
        const response = await fetch('https://h2.privacytests2.org:8902/?mode=read', { cache: 'no-store' });
        return await response.text();
      }
result, same first party:
d25496fb-946c-4b2c-918c-c34c3ef0213a,
49ecc7f2-486e-4ab7-a832-addb6a421887,
019595da-6f6c-41ef-b1f1-2fc0aece4fec,
691eb37e-8f1e-4fa1-a652-69d8928d3cec,
00c1f48b-e6be-47b9-9c44-dd5281945dc2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
H3 connection
HTTP/3 is a new standard HTTP connection protocol, still in draft but widely supported by browsers. If it is not partitioned, it can be used to track users across websites.
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
        for (let i = 0; i < 3; ++i) {
          await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
          await sleepMs(500);
        }
        // Are we now connecting over h3?
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
        const text = await response.text();
        // Empty response text indicates we are not connecting over h3:
        if (text.trim() === '') {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id');
        return await response.text();
      }
result, same first party:
f11c34498b69557b709743123cd3ee5d,
,
c882b76a780466b08ffc1bd3785ffb2f,
76372dfb639765fd4a1ae40c5d5e0fa2,
4fd9a19f2dc9fc197a008ec0b426d692
result, different first party: , , , ,
unsupported: false, true, false, false, false
passed: true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
        for (let i = 0; i < 3; ++i) {
          await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
          await sleepMs(500);
        }
        // Are we now connecting over h3?
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
        const text = await response.text();
        // Empty response text indicates we are not connecting over h3:
        if (text.trim() === '') {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id');
        return await response.text();
      }
result, same first party:
9751a4396262a5625f4723c80d06f4a2,
,
fb970cf99352ec257b963fd4d5b8d899,
d9a6b98a9a70d6d39adeb048aa8123bd,
e7e012dd78999e26494c85d90091f113
result, different first party: , , , ,
unsupported: false, true, false, false, false
passed: true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
        for (let i = 0; i < 3; ++i) {
          await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
          await sleepMs(500);
        }
        // Are we now connecting over h3?
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
        const text = await response.text();
        // Empty response text indicates we are not connecting over h3:
        if (text.trim() === '') {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id');
        return await response.text();
      }
result, same first party:
f3608ede89431bbb694c4fd24546ddfb,
,
f76c053c9b10af55e443f359e186350d,
55ef5e54bbacfc66a9ff6a31f1d24d7a,
06ca4f81fecead6edb04099bc7d83b07
result, different first party: , , , ,
unsupported: false, true, false, false, false
passed: true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
        for (let i = 0; i < 3; ++i) {
          await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
          await sleepMs(500);
        }
        // Are we now connecting over h3?
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
        const text = await response.text();
        // Empty response text indicates we are not connecting over h3:
        if (text.trim() === '') {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id');
        return await response.text();
      }
result, same first party:
fb9fae17465d9ebf4d21f6b3c55c53b3,
,
764287d51ef7109b149503e82389c17e,
87a404de694bd222eda34654e9000464,
16b1b54f95f998bf935a33dfc09147a4
result, different first party: , , , ,
unsupported: false, true, false, false, false
passed: true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
        for (let i = 0; i < 3; ++i) {
          await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
          await sleepMs(500);
        }
        // Are we now connecting over h3?
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
        const text = await response.text();
        // Empty response text indicates we are not connecting over h3:
        if (text.trim() === '') {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id');
        return await response.text();
      }
result, same first party:
6d5f691afcbe3c2cc7a65385fadd2c03,
,
e0034b592ebd0a64e32097d061cc81e0,
61178b66635c8144ad145ab27dace578,
5141d38785a25adcc5a39b587a0c7d60
result, different first party: , , , ,
unsupported: false, true, false, false, false
passed: true, true, true, true
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
        for (let i = 0; i < 3; ++i) {
          await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
          await sleepMs(500);
        }
        // Are we now connecting over h3?
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
        const text = await response.text();
        // Empty response text indicates we are not connecting over h3:
        if (text.trim() === '') {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id');
        return await response.text();
      }
result, same first party: , , , ,
result, different first party: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
        for (let i = 0; i < 3; ++i) {
          await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
          await sleepMs(500);
        }
        // Are we now connecting over h3?
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
        const text = await response.text();
        // Empty response text indicates we are not connecting over h3:
        if (text.trim() === '') {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id');
        return await response.text();
      }
result, same first party:
904824a1a9bc4dfdbac50af8f1004922,
,
6c7648c776ba699e427d24f1af22eb71,
45332e2325f53cf5f25ba590a4afdc9d,
4ea6d93d00b80af6789c03c5e6edb38e
result, different first party: , , , ,
unsupported: false, true, false, false, false
passed: true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Ensure that we can switch over to h3 via alt-svc:
        for (let i = 0; i < 3; ++i) {
          await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
          await sleepMs(500);
        }
        // Are we now connecting over h3?
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id', { cache: 'no-store' });
        const text = await response.text();
        // Empty response text indicates we are not connecting over h3:
        if (text.trim() === '') {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const response = await fetch('https://h3.privacytests2.org:4434/connection_id');
        return await response.text();
      }
result, same first party:
31b0bee66387ef5ab0b10b594d538f3a,
,
61374ce10828bcdf716a9da2a739bfab,
a64c2d39fa9b88a1eacb8800b46b1f06,
a04a77265d722fc7972a9350a101715b
result, different first party: , , , ,
unsupported: false, true, false, false, false
passed: true, true, true, true
test failed: false, false, false, false, false
HSTS cache
The HTTP Strict-Transport-Security response header allows a website to signal that it should only be accessed via HTTPS. The browser remembers this directive in a database, but if this database is not partitioned, then it can be used to track users across websites."
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
HSTS cache (fetch)
The HTTP Strict-Transport-Security response header allows a website to signal that it should only be accessed via HTTPS. The browser remembers this directive in a database, but if this database is not partitioned, then it can be used to track users across websites."
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: set HSTS flag
read: read HSTS flag
result, same first party: not tested, not tested, not tested, not tested, not tested
result, different first party:
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https,
Upgraded to https
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
iframe cache
An iframe is an element in a web page than allows websites to embed a second web page. Caching of this web page could be abused for cross-site tracking.
Passed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
image cache
Caching of images in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.
Passed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
indexedDB
The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same first party:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9,
c2a5940f-425e-422d-94f9-135afd1fa5ea,
57cd9660-8597-4dd5-8ead-d9990f4ed669,
7a2fd1a9-5514-426a-9836-5d3de3ede32e,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab
result, different first party: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same first party:
baef3f1a-5eb8-4825-84b3-1a351cd4f946,
95b5d526-459c-4275-9c03-8eaab6524d00,
b94f8b75-f692-4a74-be67-2d129ee968fa,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc
result, different first party: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same first party:
671d85f5-2fe2-4980-b513-c2f951b1388f,
19f09c1b-70dc-49ff-89db-7b0581136a7f,
46e1edd3-9d95-48b2-95d2-72f092fd6a60,
ffce8953-f69a-4566-9acb-9eafce986a0e,
f68151b8-82c0-4851-9c11-5e979d40d969
result, different first party: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same first party:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c,
c50594c9-46ea-4084-a075-e3dd6f8cefff,
374de0a5-76f5-453d-a8e7-6381fc3a060e,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1,
1f02f498-5031-4d2b-95bb-15e87a1e27dd
result, different first party: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same first party:
500f9151-21f8-4127-8879-e18e11248a6f,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f,
e2a80b15-91bb-43cd-b500-f80f6abd55f8,
d62ff542-078b-452c-a3f0-eb1b0b4b8247,
3e929897-9320-4cef-a12a-6563e2c86cb2
result, different first party: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same first party:
69cadac6-f50d-4990-8e84-00bb2148b1b4,
e2db4657-3148-411b-aa92-1013549daecf,
840f0ae2-df03-4b37-bb48-b3bda8ac4698,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba
result, different first party: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same first party:
aa3860ea-4a49-454f-8472-b9de28cf07b4,
0f6f042c-429c-4cee-8107-0fe99108f4a8,
860ce808-4495-4d78-a786-45a79cec9a0e,
38791220-517f-458a-90fd-65a0b062aa0a,
86c36e81-5851-4074-b515-aed4262a971d
result, different first party: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same first party:
d25496fb-946c-4b2c-918c-c34c3ef0213a,
49ecc7f2-486e-4ab7-a832-addb6a421887,
019595da-6f6c-41ef-b1f1-2fc0aece4fec,
691eb37e-8f1e-4fa1-a652-69d8928d3cec,
00c1f48b-e6be-47b9-9c44-dd5281945dc2
result, different first party: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
localStorage
The localStorage API gives websites access to a key-value database that will remain available across visits. If the localStorage API is not partitioned or blocked, it can also be used to track users across websites.
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same first party:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9,
c2a5940f-425e-422d-94f9-135afd1fa5ea,
57cd9660-8597-4dd5-8ead-d9990f4ed669,
7a2fd1a9-5514-426a-9836-5d3de3ede32e,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same first party:
baef3f1a-5eb8-4825-84b3-1a351cd4f946,
95b5d526-459c-4275-9c03-8eaab6524d00,
b94f8b75-f692-4a74-be67-2d129ee968fa,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same first party:
671d85f5-2fe2-4980-b513-c2f951b1388f,
19f09c1b-70dc-49ff-89db-7b0581136a7f,
46e1edd3-9d95-48b2-95d2-72f092fd6a60,
ffce8953-f69a-4566-9acb-9eafce986a0e,
f68151b8-82c0-4851-9c11-5e979d40d969
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same first party:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c,
c50594c9-46ea-4084-a075-e3dd6f8cefff,
374de0a5-76f5-453d-a8e7-6381fc3a060e,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1,
1f02f498-5031-4d2b-95bb-15e87a1e27dd
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same first party:
500f9151-21f8-4127-8879-e18e11248a6f,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f,
e2a80b15-91bb-43cd-b500-f80f6abd55f8,
d62ff542-078b-452c-a3f0-eb1b0b4b8247,
3e929897-9320-4cef-a12a-6563e2c86cb2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same first party:
69cadac6-f50d-4990-8e84-00bb2148b1b4,
e2db4657-3148-411b-aa92-1013549daecf,
840f0ae2-df03-4b37-bb48-b3bda8ac4698,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same first party:
aa3860ea-4a49-454f-8472-b9de28cf07b4,
0f6f042c-429c-4cee-8107-0fe99108f4a8,
860ce808-4495-4d78-a786-45a79cec9a0e,
38791220-517f-458a-90fd-65a0b062aa0a,
86c36e81-5851-4074-b515-aed4262a971d
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same first party:
d25496fb-946c-4b2c-918c-c34c3ef0213a,
49ecc7f2-486e-4ab7-a832-addb6a421887,
019595da-6f6c-41ef-b1f1-2fc0aece4fec,
691eb37e-8f1e-4fa1-a652-69d8928d3cec,
00c1f48b-e6be-47b9-9c44-dd5281945dc2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
locks
navigator.locks (only supported in some browsers) allows scripts on multiple tabs to coordinate. If this API is not partitioned, it can be used for cross-site tracking.
Passed
write: async (key) => {
        if (navigator.locks) {
          navigator.locks.request(key, lock => new Promise((resolve) => {}));
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].clientId;
        } else {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (navigator.locks) {
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].name;
        }
      }
result, same first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
result, different first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: async (key) => {
        if (navigator.locks) {
          navigator.locks.request(key, lock => new Promise((resolve) => {}));
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].clientId;
        } else {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (navigator.locks) {
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].name;
        }
      }
result, same first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
result, different first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: async (key) => {
        if (navigator.locks) {
          navigator.locks.request(key, lock => new Promise((resolve) => {}));
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].clientId;
        } else {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (navigator.locks) {
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].name;
        }
      }
result, same first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
result, different first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: async (key) => {
        if (navigator.locks) {
          navigator.locks.request(key, lock => new Promise((resolve) => {}));
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].clientId;
        } else {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (navigator.locks) {
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].name;
        }
      }
result, same first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
result, different first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: async (key) => {
        if (navigator.locks) {
          navigator.locks.request(key, lock => new Promise((resolve) => {}));
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].clientId;
        } else {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (navigator.locks) {
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].name;
        }
      }
result, same first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
result, different first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: async (key) => {
        if (navigator.locks) {
          navigator.locks.request(key, lock => new Promise((resolve) => {}));
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].clientId;
        } else {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (navigator.locks) {
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].name;
        }
      }
result, same first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
result, different first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: async (key) => {
        if (navigator.locks) {
          navigator.locks.request(key, lock => new Promise((resolve) => {}));
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].clientId;
        } else {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (navigator.locks) {
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].name;
        }
      }
result, same first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
result, different first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
Passed
write: async (key) => {
        if (navigator.locks) {
          navigator.locks.request(key, lock => new Promise((resolve) => {}));
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].clientId;
        } else {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (navigator.locks) {
          const queryResult = await navigator.locks.query();
          return queryResult.held[0].name;
        }
      }
result, same first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
result, different first party:
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name'),
Error: undefined is not an object (evaluating 'queryResult.held[0].name')
unsupported: false, false, false, false, false
passed: undefined
test failed: true, true, true, true, true
prefetch cache
A <link rel='prefetch'...> suggests to browsers they should fetch a resource ahead of time and cache it. But if browsers don't partition this cache, it can be used to track users across websites.
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different first party:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
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 {
          const worker = new window.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 () => {
        const worker = new window.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 ((new URL(window.location)).searchParams.get('thirdparty') === 'same' && message === 'none') {
          throw new Error('Unsupported');
        }
        return message;
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party: none, none, none, none, none
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
        try {
          const worker = new window.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 () => {
        const worker = new window.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 ((new URL(window.location)).searchParams.get('thirdparty') === 'same' && message === 'none') {
          throw new Error('Unsupported');
        }
        return message;
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party: none, none, none, none, none
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
        try {
          const worker = new window.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 () => {
        const worker = new window.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 ((new URL(window.location)).searchParams.get('thirdparty') === 'same' && message === 'none') {
          throw new Error('Unsupported');
        }
        return message;
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party: none, none, none, none, none
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
        try {
          const worker = new window.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 () => {
        const worker = new window.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 ((new URL(window.location)).searchParams.get('thirdparty') === 'same' && message === 'none') {
          throw new Error('Unsupported');
        }
        return message;
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party: none, none, none, none, none
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
        try {
          const worker = new window.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 () => {
        const worker = new window.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 ((new URL(window.location)).searchParams.get('thirdparty') === 'same' && message === 'none') {
          throw new Error('Unsupported');
        }
        return message;
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party: none, none, none, none, none
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
        try {
          const worker = new window.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 () => {
        const worker = new window.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 ((new URL(window.location)).searchParams.get('thirdparty') === 'same' && message === 'none') {
          throw new Error('Unsupported');
        }
        return message;
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party: none, none, none, none, none
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
        try {
          const worker = new window.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 () => {
        const worker = new window.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 ((new URL(window.location)).searchParams.get('thirdparty') === 'same' && message === 'none') {
          throw new Error('Unsupported');
        }
        return message;
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party: none, none, none, none, none
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
        try {
          const worker = new window.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 () => {
        const worker = new window.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 ((new URL(window.location)).searchParams.get('thirdparty') === 'same' && message === 'none') {
          throw new Error('Unsupported');
        }
        return message;
      }
result, same first party:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
result, different first party: none, none, none, none, none
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
TLS Session ID
The TLS protocol is used by HTTPS to make connections secure. If the browser were to re-use a TLS session, then the session ID could be used to track users across websites.
Passed
write: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
read: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
result, same first party:
55a5d68a28b0aa211f9ebcb33d494bb68543539cb6ef65336618501cbf3d9b1e,
44953cafad39ee73eb43ccfa348b669f0e0a0a3321f26050a7b8c2feb63ebf75,
5a938c32aed0eeef3446f0e58f733a2c1f79b0ef343c0eadc182d5d1615da20c,
44a3b4cfa29bcf953ecb7935d24bedb595ce3fd6293489ce5706bc3071297e59,
1337e40f3367987fda2635c89329c3c0c061802233f75720a0f854ad908592d3
result, different first party:
7cc6aa7a40b382751e75cb418644954058a5722ce4b411da8a34ce4771854fc3,
6e7b41ff69b01fc905233b24be426d154d5f9f27287134f90a040869d39c7796,
3f0434a3215fd5e0eef880cfa42183b8ff8ae7c065c8644c65e346b5bd6903ba,
72243b2cebc62de73e5c09293ba61b236fb7a37c78f3ec183f25bc94906f481f,
82d393fb127391ca886ce8af394eabe26475954c1de9d8418aaeb579cf650829
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
read: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
result, same first party:
0e74bca525962fdf0e9abf3d963e493d6d904483b8129517e0d10404adb8526b,
1f9a8610b3d5b7ba137535abaca45379bc92c63df1b99132777da3e03125b2c6,
f9676575914f287b04a6f7e8778b4c5f3b61b4d38bea7374ec2f8212fd18587b,
34329bba0de23c156a556e764374b95fbbcf63102da65afa9cd2013f38e87b6a,
e3df56846299bf643c4f1e3632be34120992228c19e2a97e00302e83084f374b
result, different first party:
24fe3da89a572336f66bd765476afb6ebd42b3f43934961724f269aab4291cf1,
2b8e87da1c12087e58a104df7b6a6293ca45846933194ddafe33a17889e3cdc3,
3c5257f39ff74864ca71a17d881b3114bc54f730ce1a272b5bd8613e3875a21c,
a78e5152d4b54377cbace59fc77c48292582430422db104c4e0d44e179c9e1cb,
a761595e663198d525bb4cfa3fced1b99a839953fd59f3e83e72b95f637ead56
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
read: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
result, same first party:
98d6593a2327fbd77a1f8ee490f90eebab1327c64f53dac98fb5d0e2786e7f93,
bfc149b446343c65fd93687ff1c975657d748fe26e61660ea96789372ea0beff,
3b393883cc57f838b1162e1f0924f517bfa560968ad3ce06036e2d78a4c6e808,
30cc60ad85d626674a37a78d35d9905eeb6f2394aa4e31efc7c2128d3922bd1b,
25a0332abca45f9885a1ec2f99d72a1754ab83c15c368e1f586e10774af24250
result, different first party:
5a7d2a45c8c88f32a0c8c35aa09822cb7d93822d29ee4b932b0aa3a5ece436d9,
284030a65dde29fc06bfbb94cc3536be333307a2ec4a216d09c7cfae56295d56,
1a63791df862c20a078a2227b97ea958e846acd6d29add298e931bb1c7339a50,
ff15456a03e8ea14ca0dbcb3e57ad835a500b8bfc69cd25292db5f7a262449da,
8f3636d63201c0ef94d65432b3f5e86e9ebd7078bf55556ae731b7801520fb02
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
read: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
result, same first party:
63f96d0e32c8d77d9f160152391783638ccc645e567f25f7bc0602d03cd89ae0,
bcc7bed9e6d4afd957555ed714293bcea0b5aaf6f4de5b4251438a5f7aeea52f,
160b5f88c8e321bfda0d6b6de83432c9d60d64534c14a1f31c5602e5327f2ef1,
13a8a0dc5a13b58a4d6b9e55ba66ddfc1a40ea0d94f03064ba51d870ed85d8d4,
87f934628d7c7b515cb37ba11b61af83f8398a0241afed91f199645a67a3b908
result, different first party:
3b17e616750f003de2301fbcb867a0d4a289a2b1f383641de59c6219f5d14a51,
bcb8ad245c588dce259a25c253c504a77c83526dd64ea0e2cdbd179acc022e10,
8fa58ada0a1e08827f785c970b3cbb696cbf601751d348266b516a4338c8e267,
fe7a4070392f6819d74c37023e0d851df03a002a3c2248f015c46cb42e5b5c1a,
60e2dcf01cd9748487b8ea65b573d776b85df7f8bc7ee59bbe55095896404329
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
read: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
result, same first party:
42442881f36b598e44ce198167430699632cc6fa44e206a899486bd3ba0d0a41,
ecd128fce6549d8e00bc5ea3a3897edd68cf505dccacd64fbedb7cbdc8d61824,
0fe588354b63d91759869818dc571595c0e2df1f2a062ee1b85cd3a28e874427,
0d3a258305e4f3e0d5deeee94299a0a404227d02bf5e69f79621e2713b548f13,
14c48dddae3220c9d8560b662c04e6741c0d843b051e0a3887d22aa2507c989a
result, different first party:
3514fbcb4538693b4c3307d5794932554cb9985f6be0d1698be3351d1aeda2f2,
86c3a648c77e5506e4aa7812060fbf0db8029e2213a2a5d21e0244b2c4d9f9f8,
6c46789a865f1da66bff575a4880464f9333dba72f5e0dd171e7c32f53833726,
5265d1a72ce46439ded9950b99c8cf4762cf0bd849365408376ba294e41957bd,
e5a4cf90fc115f6e29e4e32b4e38bcf47ef202396f7c80179d0d686dae2591dc
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
read: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
result, same first party:
aaba7b5876f5b992c03af0245a06795590f1cc9fd16d53b094f2ae98f4e4d47e,
b59e3ac8929c7ff146b871ed40398a73e0590171922be7a518fff45bed6238d8,
37cd7fa57a298bd7d0352eff62b78c021c92e27cf3d11869dc6fa9ea040cdfcc,
c08d86f83c852e7c757eed43d13e0f37c3ce2b84eae9308809e14d0aed0800e9,
e9252f87b933bb81b720e5d1d72313cddc0a95448a071cb89ce33b63879dbe7c
result, different first party:
8fd660a43e1fb1446ae67030c91f25ccb1d2f8f280b344bb7c7c9309d008e812,
692c7d145f19e5941fab3f89ab3c2ef4bc3ac159c7a57eb7459652df4586fc40,
8bd5ede16792c738d3c3cddbd433373b46461cfd429c934cbdad5fd2f74aafe9,
6c854999c25da8252047c8c70f2470b7884445382719e337d40ddab049a5c9b6,
44c98cb4332f9dd7712aa517a93bba0bd34d8c3e7ab7a9196e06fede30882bc6
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
read: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
result, same first party:
9e080e4630f1f57d4fea73c84a32349e0967427589df5fc4a65f2b42608df88e,
3a51861adb0ea594b86c734173e3c6fa9abad77c6a2b93fc03219b1142247775,
d79aa47d4f375f94d96141f198deb68435a73a6e32f8ae906fdbdac7b5ef45f9,
4c0262659e0d38991a286348f39060b3537f9b44258caf4f8b3019f143b4db3a,
af0491e24df3c01c214f0d92a5649264f304aa65f281693c64173f7ac6490382
result, different first party:
a280aedac7084ded5b536884b15c55f7535a3ac767c20c21e049d0e20da0d60f,
6176820c52505ce54e6d648835af291cc420bf75e462e7978c05dc92b123d62c,
3f70a391d75e173ab6e52c190b0537590d8cc60521ed732c67bd58431750eaa8,
0deb4791070d7ca385acc18a7fd8c694d4d77c7653a7c10d2e47cb718a153717,
7c11ddc659b07e38ce89543550d056b8ea93053da3f47ea79ef22745ddf2d659
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
read: async () => {
        const results = await fetch('https://tls.privacytests2.org:8900/');
        return (await results.json()).sessionId;
      }
result, same first party:
ec470b83fe61190507f00a5cd80eacbbd0bdc33a98a27cf38b7f1872fb799f4a,
17038a3c162e05fdfc4b525a5d1d42f14f96a286e6867048416b6d92fe2c21a4,
65dd79c87fc5ea1628d481350ab6cfa841519f11d9d03381252f5baa72e13eb7,
dadbc1066b3fe0b938f4d81724f03a0ddbbe21f8c1dbf01786200c7868d87800,
fb4b4d8dfea907f1d86f5bc3d40502217197d456e8bd0091df15d739cd3de674
result, different first party:
add3da96f41676748c40455843ef243d5ffa3c51f3b9cd93be8fa7ea6f35b61b,
7ad44864105b6a186f359cbb7de6ab161f081fc8484a5b5a40e0afca4be84d87,
425fcf64fd4fa2748c9bef3a198ab8a40d8d13d6a931d32db01f4018e8f9d159,
2938bc8ffe50c0c68841fe23486f929820b1cc8bec5931bc9593534d3b8818d9,
d0a7475440aea0c9417422999821a2a58b23d5b9ea5333eadebe4305f6860211
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
XMLHttpRequest cache
Similar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.
Passed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same first party: 1, 1, 1, 1, 1
result, different first party: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Navigation testsWhich browsers prevent websites from sharing tracking data when you click on a link?
When you click a hyperlink to navigate your browser from one site to another, certain browser APIs allow the first site to communicate to the second site. These privacy vulnerabilities can be fixed by introducing new limits on how much data is transfered between sites.',
document.referrer
The Referer [sic] request header is a mechanism used by browsers to let a website know where the user is visiting from. This header is inherently tracking users across websites. In recent times, browsers have switched to a policy of trimming a referrer to convey less tracking information, but Referer continues to convey cross-site tracking data by default.
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { /* do nothing */ }
read: () => document.referrer
result, same first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
result, different first party:
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/,
https://test-pages.privacytests2.org/
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
sessionStorage
The sessionStorage API is similar to the localStorage API, but it does not persist across tabs or across browser sessions. Nonetheless, it can be used to track users if they navigate from one website to another. This tracking can be thwarted by partitioning sessionStorage between websites.
Passed
write: (secret) => window.sessionStorage.setItem('secret', secret)
read: () => window.sessionStorage.getItem('secret')
result, same first party:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9,
c2a5940f-425e-422d-94f9-135afd1fa5ea,
57cd9660-8597-4dd5-8ead-d9990f4ed669,
7a2fd1a9-5514-426a-9836-5d3de3ede32e,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => window.sessionStorage.setItem('secret', secret)
read: () => window.sessionStorage.getItem('secret')
result, same first party:
baef3f1a-5eb8-4825-84b3-1a351cd4f946,
95b5d526-459c-4275-9c03-8eaab6524d00,
b94f8b75-f692-4a74-be67-2d129ee968fa,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => window.sessionStorage.setItem('secret', secret)
read: () => window.sessionStorage.getItem('secret')
result, same first party:
671d85f5-2fe2-4980-b513-c2f951b1388f,
19f09c1b-70dc-49ff-89db-7b0581136a7f,
46e1edd3-9d95-48b2-95d2-72f092fd6a60,
ffce8953-f69a-4566-9acb-9eafce986a0e,
f68151b8-82c0-4851-9c11-5e979d40d969
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => window.sessionStorage.setItem('secret', secret)
read: () => window.sessionStorage.getItem('secret')
result, same first party:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c,
c50594c9-46ea-4084-a075-e3dd6f8cefff,
374de0a5-76f5-453d-a8e7-6381fc3a060e,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1,
1f02f498-5031-4d2b-95bb-15e87a1e27dd
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => window.sessionStorage.setItem('secret', secret)
read: () => window.sessionStorage.getItem('secret')
result, same first party:
500f9151-21f8-4127-8879-e18e11248a6f,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f,
e2a80b15-91bb-43cd-b500-f80f6abd55f8,
d62ff542-078b-452c-a3f0-eb1b0b4b8247,
3e929897-9320-4cef-a12a-6563e2c86cb2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => window.sessionStorage.setItem('secret', secret)
read: () => window.sessionStorage.getItem('secret')
result, same first party:
69cadac6-f50d-4990-8e84-00bb2148b1b4,
e2db4657-3148-411b-aa92-1013549daecf,
840f0ae2-df03-4b37-bb48-b3bda8ac4698,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => window.sessionStorage.setItem('secret', secret)
read: () => window.sessionStorage.getItem('secret')
result, same first party:
aa3860ea-4a49-454f-8472-b9de28cf07b4,
0f6f042c-429c-4cee-8107-0fe99108f4a8,
860ce808-4495-4d78-a786-45a79cec9a0e,
38791220-517f-458a-90fd-65a0b062aa0a,
86c36e81-5851-4074-b515-aed4262a971d
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => window.sessionStorage.setItem('secret', secret)
read: () => window.sessionStorage.getItem('secret')
result, same first party:
d25496fb-946c-4b2c-918c-c34c3ef0213a,
49ecc7f2-486e-4ab7-a832-addb6a421887,
019595da-6f6c-41ef-b1f1-2fc0aece4fec,
691eb37e-8f1e-4fa1-a652-69d8928d3cec,
00c1f48b-e6be-47b9-9c44-dd5281945dc2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
window.name
The window.name API allows websites to store data that will persist after the user has navigated the tab to a different website. This mechanism could be partitioned so that data is not allowed to persist between websites.
Passed
write: (secret) => { window.name = 'name_' + secret; }
read: () => window.name
result, same first party:
name_3d75ac7a-302f-4fa5-be9c-4f10e9a483c9,
name_c2a5940f-425e-422d-94f9-135afd1fa5ea,
name_57cd9660-8597-4dd5-8ead-d9990f4ed669,
name_7a2fd1a9-5514-426a-9836-5d3de3ede32e,
name_ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.name = 'name_' + secret; }
read: () => window.name
result, same first party:
name_baef3f1a-5eb8-4825-84b3-1a351cd4f946,
name_95b5d526-459c-4275-9c03-8eaab6524d00,
name_b94f8b75-f692-4a74-be67-2d129ee968fa,
name_ef19b766-fc54-4893-9a7d-487b7b3fc8d2,
name_ee56bc51-9b8c-47d9-9e35-3f115c8f0adc
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.name = 'name_' + secret; }
read: () => window.name
result, same first party:
name_671d85f5-2fe2-4980-b513-c2f951b1388f,
name_19f09c1b-70dc-49ff-89db-7b0581136a7f,
name_46e1edd3-9d95-48b2-95d2-72f092fd6a60,
name_ffce8953-f69a-4566-9acb-9eafce986a0e,
name_f68151b8-82c0-4851-9c11-5e979d40d969
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.name = 'name_' + secret; }
read: () => window.name
result, same first party:
name_83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c,
name_c50594c9-46ea-4084-a075-e3dd6f8cefff,
name_374de0a5-76f5-453d-a8e7-6381fc3a060e,
name_d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1,
name_1f02f498-5031-4d2b-95bb-15e87a1e27dd
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.name = 'name_' + secret; }
read: () => window.name
result, same first party:
name_500f9151-21f8-4127-8879-e18e11248a6f,
name_75dce9f1-1f55-48a6-98a8-d37a3f5bef9f,
name_e2a80b15-91bb-43cd-b500-f80f6abd55f8,
name_d62ff542-078b-452c-a3f0-eb1b0b4b8247,
name_3e929897-9320-4cef-a12a-6563e2c86cb2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.name = 'name_' + secret; }
read: () => window.name
result, same first party:
name_69cadac6-f50d-4990-8e84-00bb2148b1b4,
name_e2db4657-3148-411b-aa92-1013549daecf,
name_840f0ae2-df03-4b37-bb48-b3bda8ac4698,
name_9dce40b8-d7a2-4805-959f-d9b0aa39ca27,
name_d4418a02-81c8-41d1-93b7-2ca9f2e677ba
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.name = 'name_' + secret; }
read: () => window.name
result, same first party:
name_aa3860ea-4a49-454f-8472-b9de28cf07b4,
name_0f6f042c-429c-4cee-8107-0fe99108f4a8,
name_860ce808-4495-4d78-a786-45a79cec9a0e,
name_38791220-517f-458a-90fd-65a0b062aa0a,
name_86c36e81-5851-4074-b515-aed4262a971d
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.name = 'name_' + secret; }
read: () => window.name
result, same first party:
name_d25496fb-946c-4b2c-918c-c34c3ef0213a,
name_49ecc7f2-486e-4ab7-a832-addb6a421887,
name_019595da-6f6c-41ef-b1f1-2fc0aece4fec,
name_691eb37e-8f1e-4fa1-a652-69d8928d3cec,
name_00c1f48b-e6be-47b9-9c44-dd5281945dc2
result, different first party: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
HTTPS testsWhich browsers prevent unencrypted network connections?
HTTPS is the protocol that web browsers use to connect securely to websites. When HTTPS is being used, the connection is encrypted so that third parties on the network cannot read content being sent between the server and your browser. In the past, insecure connections were the default and websites would need to actively request that a browser use HTTPS. Now the status quo is shifting, and browser makers are moving toward a world where HTTPS is the default protocol.`
Insecure website warning
Checks to see if the browser stops loading an insecure website and warns the user before giving them the option to continue. Known as HTTPS-Only Mode in some browsers.
Failed
passed: false, false, false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Failed
passed: false, false, false, false, false
result:
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded,
Insecure website loaded
Upgradable address
Checks to see if an insecure address entered into the browser's address bar is upgraded to HTTPS whenever possible.
Passed
upgraded: true, true, true, true, true
passed: true, true, true, true, true
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Upgradable hyperlink
Checks to see if the user has clicked on a hyperlink to an insecure address, if the browser upgrades that address to HTTPS whenever possible.
Passed
upgraded: true, true, true, true, true
passed: true, true, true, true, true
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Passed
upgraded: true, true, true, true, true
passed: true, true, true, true, true
Failed
upgraded: false, false, false, false, false
passed: false, false, false, false, false
Upgradable image
Checks to see if the browser attempts to upgrade an insecure address for an image to HTTPS whenever possible.
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Passed
passed: true, true, true, true, true
result: upgraded, upgraded, upgraded, upgraded, upgraded
Upgradable script
Checks to see if the browser attempts to upgrade an insecure address for an script to HTTPS whenever possible.
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
Passed
passed: true, true, true, true, true
result: blocked, blocked, blocked, blocked, blocked
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.
Failed
SNI_status: plaintext
passed: false, false, false, false, false
Failed
SNI_status: plaintext
passed: false, false, false, false, false
Failed
SNI_status: plaintext
passed: false, false, false, false, false
Failed
SNI_status: plaintext
passed: false, false, false, false, false
Failed
SNI_status: plaintext
passed: false, false, false, false, false
Failed
SNI_status: plaintext
passed: false, false, false, false, false
Failed
SNI_status: plaintext
passed: false, false, false, false, false
Failed
SNI_status: plaintext
passed: false, false, false, false, false
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.
Failed
header value: undefined
passed: false, false, false, false, false
Failed
header value: undefined
passed: false, false, false, false, false
Passed
header value: 1
passed: true, true, true, true, true
Failed
header value: undefined
passed: false, false, false, false, false
Failed
header value: undefined
passed: false, false, false, false, false
Failed
header value: undefined
passed: false, false, false, false, false
Failed
header value: undefined
passed: false, false, false, false, false
Failed
header value: undefined
passed: false, false, false, false, false
GPC enabled third-party
The Global Privacy Control is an HTTP header that can be sent by a browser to instruct a visited website not to sell the user's personal data to other parties. This test checks to see if the GPC header is sent to third-party elements on the web page.
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
IP address hidden
IP addresses can be used to uniquely identify a large percentage of users. A proxy, VPN, or Tor can mask a user's IP address.
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Failed
passed: false, false, false, false, false
Stream isolation
Browsers that use Tor can use a different Tor circuit per top-level website.
Unsupported
write: () => {
        if (!usingTor) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (usingTor) {
          return ipAddress;
        } else {
          throw new Error('Unsupported');
        }
      }
unsupported: true, true, true, true, true
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Unsupported
write: () => {
        if (!usingTor) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (usingTor) {
          return ipAddress;
        } else {
          throw new Error('Unsupported');
        }
      }
unsupported: true, true, true, true, true
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Unsupported
write: () => {
        if (!usingTor) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (usingTor) {
          return ipAddress;
        } else {
          throw new Error('Unsupported');
        }
      }
unsupported: true, true, true, true, true
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Unsupported
write: () => {
        if (!usingTor) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (usingTor) {
          return ipAddress;
        } else {
          throw new Error('Unsupported');
        }
      }
unsupported: true, true, true, true, true
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Unsupported
write: () => {
        if (!usingTor) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (usingTor) {
          return ipAddress;
        } else {
          throw new Error('Unsupported');
        }
      }
unsupported: true, true, true, true, true
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Unsupported
write: () => {
        if (!usingTor) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (usingTor) {
          return ipAddress;
        } else {
          throw new Error('Unsupported');
        }
      }
unsupported: true, true, true, true, true
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Unsupported
write: () => {
        if (!usingTor) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (usingTor) {
          return ipAddress;
        } else {
          throw new Error('Unsupported');
        }
      }
unsupported: true, true, true, true, true
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Unsupported
write: () => {
        if (!usingTor) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        if (usingTor) {
          return ipAddress;
        } else {
          throw new Error('Unsupported');
        }
      }
unsupported: true, true, true, true, true
readSameFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
readDifferentFirstParty:
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported,
Error: Unsupported
testFailed: false, false, false, false, false
Tor enabled
The Tor network sends the browser's web requests through a series of relays to hide a user's IP address, thereby helping to mask their identity and location. This test checks to see if the Tor network is being used by default.
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Failed
IsTorExit: false, false, false, false, false
passed: false, false, false, false, false
Tracking query parameter testsWhich browsers remove URL parameters that can track you?
When you browse from one web page to another, tracking companies will frequently attach a 'tracking query parameter' to the address of the second web page. That query parameter may contain a unique identifier that tracks you individually as you browse the web. And these query parameters are frequently synchronized with cookies, making them a powerful tracking vector. Web browsers can protect you from known tracking query parameters by stripping them from web addresses before your browser sends them. (The set of tracking query parameters tested here was largely borrowed from Brave.)`
__hsfp
HubSpot tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
__hssc
HubSpot tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
__hstc
HubSpot tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
__s
Drip.com email address tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
_hsenc
HubSpot tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
_openstat
Yandex tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
dclid
DoubleClick Click ID (Google)
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
fbclid
Facebook Click Identifier
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Passed
passed: true, true, true, true, true
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
gclid
Google Click Identifier
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Passed
passed: true, true, true, true, true
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
hsCtaTracking
HubSpot tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
mc_eid
Mailchimp Email ID (email recipient's address)
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
mkt_tok
Adobe Marketo tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Passed
passed: true, true, true, true, true
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
ml_subscriber
MailerLite email tracking
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
ml_subscriber_hash
MailerLite email tracking
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
msclkid
Microsoft Click ID
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
oly_anon_id
Omeda marketing 'anonymous' customer id
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
oly_enc_id
Omeda marketing 'known' customer id
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
rb_clickid
Unknown high-entropy tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
s_cid
Adobe Site Catalyst tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
vero_conv
Vero tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
vero_id
Vero tracking parameter
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
wickedid
Wicked Reports e-commerce tracking
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
yclid
Yandex Click ID
Passed
passed: true, true, true, true, true
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 3134205762172444
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Failed
value: 7805900930247793
passed: false, false, false, false, false
Tracker content blocking testsWhich browsers block important known tracking scripts and pixels?
When you visit a web page, it frequently has third-party embedded tracking content, such as scripts and tracking pixels. These embedded components spy on you. Some browsers and browser extensions maintain list of tracking companies and block their content from being loaded. This section checks to see if a browser blocks 20 of the largest trackers listed by https://whotracks.me.`
Adobe
Tests whether the browser blocks the page from loading the tracker at https://munchkin.marketo.net/munchkin.js
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true, true, true, true, true
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false, false
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true, true, true, true, true
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: false, false, false
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: , false, false
Passed
url: https://munchkin.marketo.net/munchkin.js
passed: true, true, true, true, true
Failed
url: https://munchkin.marketo.net/munchkin.js
passed: , false, false, false
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, true, true, true
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false, false, false
Passed
url: https://dpm.demdex.net/ibs
passed: true, true, true, true, true
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false, false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false, false, false
Passed
url: https://dpm.demdex.net/ibs
passed: true, true, true, true, true
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false, false, false
Failed
url: https://dpm.demdex.net/ibs
passed: false, false, false, false, false
Amazon adsystem
Tests whether the browser blocks the page from loading the tracker at https://s.amazon-adsystem.com/dcm
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true, true, true, true
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false, false, false
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true, true, true, true
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false, false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false, false, false
Passed
url: https://s.amazon-adsystem.com/dcm
passed: true, true, true, true, true
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false, false, false
Failed
url: https://s.amazon-adsystem.com/dcm
passed: false, false, false, false, false
AppNexus
Tests whether the browser blocks the page from loading the tracker at https://ib.adnxs.com/px?id=178248&t=1
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true, true, true, true
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false, false, false
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true, true, true, true
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false, false, false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false, false, false
Passed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: true, true, true, true, true
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false, false, false
Failed
url: https://ib.adnxs.com/px?id=178248&t=1
passed: false, false, false, false, false
Bing Ads
Tests whether the browser blocks the page from loading the tracker at https://bat.bing.com/bat.js
Passed
url: https://bat.bing.com/bat.js
passed: true, true, true, true, true
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false, false, false
Passed
url: https://bat.bing.com/bat.js
passed: true, true, true, true, true
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false, false, false
Passed
url: https://bat.bing.com/bat.js
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false, false, false
Failed
url: https://bat.bing.com/bat.js
passed: false, false, false, false, false
Chartbeat
Tests whether the browser blocks the page from loading the tracker at https://static.chartbeat.com/js/chartbeat.js
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true, true, true, true, true
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Passed
url: https://static.chartbeat.com/js/chartbeat.js
passed: true, true, true, true, true
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Failed
url: https://static.chartbeat.com/js/chartbeat.js
passed: false, false, false, false, false
Criteo
Tests whether the browser blocks the page from loading the tracker at https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true, true, true, true
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false, false, false
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true, true, true, true
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false, false, false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false, false, false
Passed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: true, true, true, true, true
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false, false, false
Failed
url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
passed: false, false, false, false, false
DoubleClick (Google)
Tests whether the browser blocks the page from loading the tracker at https://securepubads.g.doubleclick.net/static/glade.js
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true, true, true, true
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true, true, true, true
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: true, true, true, true, true
Failed
url: https://securepubads.g.doubleclick.net/static/glade.js
passed: false, false, false, false
Passed
url: https://securepubads.g.doubleclick.net/static/glade.js
Facebook tracking
Tests whether the browser blocks the page from loading the tracker at https://connect.facebook.net/en_US/fbevents.js
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true, true, true, true
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false, false, false
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true, true, true, true
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false, false, false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: , false, false, false, false
Passed
url: https://connect.facebook.net/en_US/fbevents.js
passed: true, true, true, true, true
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false, false, false
Failed
url: https://connect.facebook.net/en_US/fbevents.js
passed: false, false, false, false, false
Google (third-party ad pixel)
Tests whether the browser blocks the page from loading the tracker at https://www.google.com/pagead/1p-user-list/
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true, true, true, true, true
Passed
url: https://www.google.com/pagead/1p-user-list/
Passed
url: https://www.google.com/pagead/1p-user-list/
passed: true, true, true, true, true
Passed
url: https://www.google.com/pagead/1p-user-list/
Passed
url: https://www.google.com/pagead/1p-user-list/
Passed
url: https://www.google.com/pagead/1p-user-list/
Failed
url: https://www.google.com/pagead/1p-user-list/
passed: false, false, false, false
Passed
url: https://www.google.com/pagead/1p-user-list/
Google Analytics
Tests whether the browser blocks the page from loading the tracker at https://google-analytics.com/urchin.js
Passed
url: https://google-analytics.com/urchin.js
passed: true, true, true, true, true
Passed
url: https://google-analytics.com/urchin.js
Passed
url: https://google-analytics.com/urchin.js
passed: true, true, true, true, true
Passed
url: https://google-analytics.com/urchin.js
Passed
url: https://google-analytics.com/urchin.js
Passed
url: https://google-analytics.com/urchin.js
passed: true, true, true, true, true
Failed
url: https://google-analytics.com/urchin.js
passed: false, false, false, false, false
Passed
url: https://google-analytics.com/urchin.js
Google Tag Manager
Tests whether the browser blocks the page from loading the tracker at https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true, true, true, true, true
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: , false, false, false
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: true, true, true, true, true
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, false, false
Passed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: false, false, false, false
Failed
url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
passed: , false
Index Exchange
Tests whether the browser blocks the page from loading the tracker at https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true, true, true, true, true
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, true, 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, false, false
Passed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: true, true, true, true, true
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: false, false, false
Failed
url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1
passed: , false, false
New Relic
Tests whether the browser blocks the page from loading the tracker at https://js-agent.newrelic.com/nr-1212.min.js
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true, true, true, true
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false, false, false
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true, true, true, true
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false, false, false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false, false, false
Passed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: true, true, true, true, true
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false, false, false
Failed
url: https://js-agent.newrelic.com/nr-1212.min.js
passed: false, false, false, false, false
Quantcast
Tests whether the browser blocks the page from loading the tracker at https://pixel.quantserve.com/pixel
Passed
url: https://pixel.quantserve.com/pixel
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false, false, false
Passed
url: https://pixel.quantserve.com/pixel
passed: true, true, true, true, true
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false, false, false
Passed
url: https://pixel.quantserve.com/pixel
passed: true, true, true, true, true
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false, false, false
Failed
url: https://pixel.quantserve.com/pixel
passed: false, false, false, false, false
Scorecard Research Beacon
Tests whether the browser blocks the page from loading the tracker at https://sb.scorecardresearch.com/internal-c2/default/cs.js
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true, true, true, true
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true, true, true, true
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
Failed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: , false, false
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
passed: true, true, true, true, true
Passed
url: https://sb.scorecardresearch.com/internal-c2/default/cs.js
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, true, true, true
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false, false, false
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true, true, true, true, true
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false, false, false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false, false, false
Passed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: true, true, true, true, true
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false, false, false
Failed
url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json
passed: false, false, false, false, false
Twitter pixel
Tests whether the browser blocks the page from loading the tracker at https://t.co/i/adsct
Passed
url: https://t.co/i/adsct
passed: true, true, true, true, true
Failed
url: https://t.co/i/adsct
passed: false, false, false, false, false
Passed
url: https://t.co/i/adsct
passed: true, true, true, true, true
Failed
url: https://t.co/i/adsct
passed: false, false, false, false
Failed
url: https://t.co/i/adsct
passed: false, false, false, false, false
Passed
url: https://t.co/i/adsct
Failed
url: https://t.co/i/adsct
passed: false, false, false, false, false
Failed
url: https://t.co/i/adsct
passed: false, false, false, false, false
Yandex Ads
Tests whether the browser blocks the page from loading the tracker at https://yandex.ru/ads/system/header-bidding.js
Passed
url: https://yandex.ru/ads/system/header-bidding.js
passed: true, true, true, true, true
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false, false, false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false, false, false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false, false, false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false, false, false
Passed
url: https://yandex.ru/ads/system/header-bidding.js
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false, false, false
Failed
url: https://yandex.ru/ads/system/header-bidding.js
passed: false, false, false, false, false
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.
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h3, h3, h2, h3, h3
result, different session: h3, h3, h3, h3, h3
unsupported: false, false, true, false, false
passed: false, false, false, false
test failed: false, false, false, false, false
Failed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h3, h3, h2, h3, h3
result, different session: h3, h3, h3, h3, h3
unsupported: false, false, true, false, false
passed: false, false, false, false
test failed: false, false, false, false, false
Failed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h3, h3, h2, h3, h3
result, different session: h3, h3, h3, h3, h3
unsupported: false, false, true, false, false
passed: false, false, false, false
test failed: false, false, false, false, false
Failed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h3, h2, h3, h3, h3
result, different session: h3, h3, h3, h3, h3
unsupported: false, true, false, false, false
passed: false, false, false, false
test failed: false, false, false, false, false
Failed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h3, h3, h2, h3, h3
result, different session: h3, h3, h3, h3, h3
unsupported: false, false, true, false, false
passed: false, false, false, false
test failed: false, false, false, false, false
Unsupported
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h2, h2, h2, h2, h2
result, different session: h2, h2, h2, h2, h2
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h3, h3, h2, h3, h3
result, different session: h3, h3, h3, h3, h3
unsupported: false, false, true, false, false
passed: false, false, false, false
test failed: false, false, false, false, false
Failed
write: async () => {
      // Clear Alt-Svc caching first.
        let responseText = '';
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/clear');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after clear:', responseText);
        // Store "h3" state in Alt-Svc cache
        for (let i = 0; i < 3; ++i) {
          await fetch(altSvcOrigin + '/set');
          await sleepMs(100);
        }
        responseText = await fetchText(altSvcOrigin + '/protocol');
        console.log('after set:', responseText);
      }
read: async () => {
        const protocol = await fetchText(altSvcOrigin + '/protocol');
        if ((new URL(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h3, h3, h2, h3, h3
result, different session: h3, h3, h3, h3, h3
unsupported: false, false, true, false, false
passed: false, false, false, false
test failed: false, false, false, false, false
CacheStorage
The Cache API is a content storage mechanism originally introduced to support ServiceWorkers. If the same Cache object is accessible to multiple websites, it can be abused to track users.
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_1p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_1p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_1p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_1p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_1p
result, different session:
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_1p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_1p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_1p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_1p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
3896d4ce-c55d-4bf1-ae02-9cee2145850c_1p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_1p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_1p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_1p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_1p
result, different session:
3896d4ce-c55d-4bf1-ae02-9cee2145850c_1p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_1p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_1p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_1p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
5f0f614c-43fc-420e-944b-4f0a0da990bf_1p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_1p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_1p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_1p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_1p
result, different session:
5f0f614c-43fc-420e-944b-4f0a0da990bf_1p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_1p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_1p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_1p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
c30feb74-0688-4e93-a1ee-945a342e2e51_1p,
c30feb74-0688-4e93-a1ee-945a342e2e51_1p,
c30feb74-0688-4e93-a1ee-945a342e2e51_1p,
c30feb74-0688-4e93-a1ee-945a342e2e51_1p,
c30feb74-0688-4e93-a1ee-945a342e2e51_1p
result, different session:
c30feb74-0688-4e93-a1ee-945a342e2e51_1p,
c30feb74-0688-4e93-a1ee-945a342e2e51_1p,
c30feb74-0688-4e93-a1ee-945a342e2e51_1p,
c30feb74-0688-4e93-a1ee-945a342e2e51_1p,
c30feb74-0688-4e93-a1ee-945a342e2e51_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
a3efc9cf-e003-4db6-b541-110fd75a7184_1p,
a3efc9cf-e003-4db6-b541-110fd75a7184_1p,
a3efc9cf-e003-4db6-b541-110fd75a7184_1p,
a3efc9cf-e003-4db6-b541-110fd75a7184_1p,
a3efc9cf-e003-4db6-b541-110fd75a7184_1p
result, different session:
a3efc9cf-e003-4db6-b541-110fd75a7184_1p,
a3efc9cf-e003-4db6-b541-110fd75a7184_1p,
a3efc9cf-e003-4db6-b541-110fd75a7184_1p,
a3efc9cf-e003-4db6-b541-110fd75a7184_1p,
a3efc9cf-e003-4db6-b541-110fd75a7184_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
result, different session:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
4301548a-9fe6-46c1-bab3-6eca1e419c61_1p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_1p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_1p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_1p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_1p
result, different session:
4301548a-9fe6-46c1-bab3-6eca1e419c61_1p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_1p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_1p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_1p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
e2799d44-532c-43fe-aee3-305e020ebb55_1p,
e2799d44-532c-43fe-aee3-305e020ebb55_1p,
e2799d44-532c-43fe-aee3-305e020ebb55_1p,
e2799d44-532c-43fe-aee3-305e020ebb55_1p,
e2799d44-532c-43fe-aee3-305e020ebb55_1p
result, different session:
e2799d44-532c-43fe-aee3-305e020ebb55_1p,
e2799d44-532c-43fe-aee3-305e020ebb55_1p,
e2799d44-532c-43fe-aee3-305e020ebb55_1p,
e2799d44-532c-43fe-aee3-305e020ebb55_1p,
e2799d44-532c-43fe-aee3-305e020ebb55_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
cookie (HTTP)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
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.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_1p_http,
c2a5940f-425e-422d-94f9-135afd1fa5ea_1p_http,
57cd9660-8597-4dd5-8ead-d9990f4ed669_1p_http,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_1p_http,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_1p_http
result, different session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_1p_http,
c2a5940f-425e-422d-94f9-135afd1fa5ea_1p_http,
57cd9660-8597-4dd5-8ead-d9990f4ed669_1p_http,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_1p_http,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_1p_http
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_1p_http,
95b5d526-459c-4275-9c03-8eaab6524d00_1p_http,
b94f8b75-f692-4a74-be67-2d129ee968fa_1p_http,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_1p_http,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_1p_http
result, different session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_1p_http,
95b5d526-459c-4275-9c03-8eaab6524d00_1p_http,
b94f8b75-f692-4a74-be67-2d129ee968fa_1p_http,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_1p_http,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_1p_http
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session:
671d85f5-2fe2-4980-b513-c2f951b1388f_1p_http,
19f09c1b-70dc-49ff-89db-7b0581136a7f_1p_http,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_1p_http,
ffce8953-f69a-4566-9acb-9eafce986a0e_1p_http,
f68151b8-82c0-4851-9c11-5e979d40d969_1p_http
result, different session:
671d85f5-2fe2-4980-b513-c2f951b1388f_1p_http,
19f09c1b-70dc-49ff-89db-7b0581136a7f_1p_http,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_1p_http,
ffce8953-f69a-4566-9acb-9eafce986a0e_1p_http,
f68151b8-82c0-4851-9c11-5e979d40d969_1p_http
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_1p_http,
c50594c9-46ea-4084-a075-e3dd6f8cefff_1p_http,
374de0a5-76f5-453d-a8e7-6381fc3a060e_1p_http,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_1p_http,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_1p_http
result, different session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_1p_http,
c50594c9-46ea-4084-a075-e3dd6f8cefff_1p_http,
374de0a5-76f5-453d-a8e7-6381fc3a060e_1p_http,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_1p_http,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_1p_http
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session:
500f9151-21f8-4127-8879-e18e11248a6f_1p_http,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_1p_http,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_1p_http,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_1p_http,
3e929897-9320-4cef-a12a-6563e2c86cb2_1p_http
result, different session:
500f9151-21f8-4127-8879-e18e11248a6f_1p_http,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_1p_http,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_1p_http,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_1p_http,
3e929897-9320-4cef-a12a-6563e2c86cb2_1p_http
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session:
69cadac6-f50d-4990-8e84-00bb2148b1b4_1p_http,
e2db4657-3148-411b-aa92-1013549daecf_1p_http,
840f0ae2-df03-4b37-bb48-b3bda8ac4698_1p_http,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27_1p_http,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba_1p_http
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_1p_http,
0f6f042c-429c-4cee-8107-0fe99108f4a8_1p_http,
860ce808-4495-4d78-a786-45a79cec9a0e_1p_http,
38791220-517f-458a-90fd-65a0b062aa0a_1p_http,
86c36e81-5851-4074-b515-aed4262a971d_1p_http
result, different session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_1p_http,
0f6f042c-429c-4cee-8107-0fe99108f4a8_1p_http,
860ce808-4495-4d78-a786-45a79cec9a0e_1p_http,
38791220-517f-458a-90fd-65a0b062aa0a_1p_http,
86c36e81-5851-4074-b515-aed4262a971d_1p_http
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_1p_http,
49ecc7f2-486e-4ab7-a832-addb6a421887_1p_http,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_1p_http,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_1p_http,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_1p_http
result, different session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_1p_http,
49ecc7f2-486e-4ab7-a832-addb6a421887_1p_http,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_1p_http,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_1p_http,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_1p_http
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
cookie (JS)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
Failed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_1p_js,
c2a5940f-425e-422d-94f9-135afd1fa5ea_1p_js,
57cd9660-8597-4dd5-8ead-d9990f4ed669_1p_js,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_1p_js,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_1p_js
result, different session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_1p_js,
c2a5940f-425e-422d-94f9-135afd1fa5ea_1p_js,
57cd9660-8597-4dd5-8ead-d9990f4ed669_1p_js,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_1p_js,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_1p_js
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_1p_js,
95b5d526-459c-4275-9c03-8eaab6524d00_1p_js,
b94f8b75-f692-4a74-be67-2d129ee968fa_1p_js,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_1p_js,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_1p_js
result, different session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_1p_js,
95b5d526-459c-4275-9c03-8eaab6524d00_1p_js,
b94f8b75-f692-4a74-be67-2d129ee968fa_1p_js,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_1p_js,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_1p_js
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
671d85f5-2fe2-4980-b513-c2f951b1388f_1p_js,
19f09c1b-70dc-49ff-89db-7b0581136a7f_1p_js,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_1p_js,
ffce8953-f69a-4566-9acb-9eafce986a0e_1p_js,
f68151b8-82c0-4851-9c11-5e979d40d969_1p_js
result, different session:
671d85f5-2fe2-4980-b513-c2f951b1388f_1p_js,
19f09c1b-70dc-49ff-89db-7b0581136a7f_1p_js,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_1p_js,
ffce8953-f69a-4566-9acb-9eafce986a0e_1p_js,
f68151b8-82c0-4851-9c11-5e979d40d969_1p_js
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_1p_js,
c50594c9-46ea-4084-a075-e3dd6f8cefff_1p_js,
374de0a5-76f5-453d-a8e7-6381fc3a060e_1p_js,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_1p_js,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_1p_js
result, different session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_1p_js,
c50594c9-46ea-4084-a075-e3dd6f8cefff_1p_js,
374de0a5-76f5-453d-a8e7-6381fc3a060e_1p_js,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_1p_js,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_1p_js
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
500f9151-21f8-4127-8879-e18e11248a6f_1p_js,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_1p_js,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_1p_js,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_1p_js,
3e929897-9320-4cef-a12a-6563e2c86cb2_1p_js
result, different session:
500f9151-21f8-4127-8879-e18e11248a6f_1p_js,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_1p_js,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_1p_js,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_1p_js,
3e929897-9320-4cef-a12a-6563e2c86cb2_1p_js
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
69cadac6-f50d-4990-8e84-00bb2148b1b4_1p_js,
e2db4657-3148-411b-aa92-1013549daecf_1p_js,
840f0ae2-df03-4b37-bb48-b3bda8ac4698_1p_js,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27_1p_js,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba_1p_js
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_1p_js,
0f6f042c-429c-4cee-8107-0fe99108f4a8_1p_js,
860ce808-4495-4d78-a786-45a79cec9a0e_1p_js,
38791220-517f-458a-90fd-65a0b062aa0a_1p_js,
86c36e81-5851-4074-b515-aed4262a971d_1p_js
result, different session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_1p_js,
0f6f042c-429c-4cee-8107-0fe99108f4a8_1p_js,
860ce808-4495-4d78-a786-45a79cec9a0e_1p_js,
38791220-517f-458a-90fd-65a0b062aa0a_1p_js,
86c36e81-5851-4074-b515-aed4262a971d_1p_js
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_1p_js,
49ecc7f2-486e-4ab7-a832-addb6a421887_1p_js,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_1p_js,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_1p_js,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_1p_js
result, different session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_1p_js,
49ecc7f2-486e-4ab7-a832-addb6a421887_1p_js,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_1p_js,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_1p_js,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_1p_js
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
CookieStore
The Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.
Failed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_1p,
c2a5940f-425e-422d-94f9-135afd1fa5ea_1p,
57cd9660-8597-4dd5-8ead-d9990f4ed669_1p,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_1p,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_1p
result, different session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_1p,
c2a5940f-425e-422d-94f9-135afd1fa5ea_1p,
57cd9660-8597-4dd5-8ead-d9990f4ed669_1p,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_1p,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_1p,
95b5d526-459c-4275-9c03-8eaab6524d00_1p,
b94f8b75-f692-4a74-be67-2d129ee968fa_1p,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_1p,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_1p
result, different session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_1p,
95b5d526-459c-4275-9c03-8eaab6524d00_1p,
b94f8b75-f692-4a74-be67-2d129ee968fa_1p,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_1p,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session:
671d85f5-2fe2-4980-b513-c2f951b1388f_1p,
19f09c1b-70dc-49ff-89db-7b0581136a7f_1p,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_1p,
ffce8953-f69a-4566-9acb-9eafce986a0e_1p,
f68151b8-82c0-4851-9c11-5e979d40d969_1p
result, different session:
671d85f5-2fe2-4980-b513-c2f951b1388f_1p,
19f09c1b-70dc-49ff-89db-7b0581136a7f_1p,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_1p,
ffce8953-f69a-4566-9acb-9eafce986a0e_1p,
f68151b8-82c0-4851-9c11-5e979d40d969_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_1p,
c50594c9-46ea-4084-a075-e3dd6f8cefff_1p,
374de0a5-76f5-453d-a8e7-6381fc3a060e_1p,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_1p,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_1p
result, different session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_1p,
c50594c9-46ea-4084-a075-e3dd6f8cefff_1p,
374de0a5-76f5-453d-a8e7-6381fc3a060e_1p,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_1p,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session:
500f9151-21f8-4127-8879-e18e11248a6f_1p,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_1p,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_1p,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_1p,
3e929897-9320-4cef-a12a-6563e2c86cb2_1p
result, different session:
500f9151-21f8-4127-8879-e18e11248a6f_1p,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_1p,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_1p,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_1p,
3e929897-9320-4cef-a12a-6563e2c86cb2_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session:
69cadac6-f50d-4990-8e84-00bb2148b1b4_1p,
e2db4657-3148-411b-aa92-1013549daecf_1p,
840f0ae2-df03-4b37-bb48-b3bda8ac4698_1p,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27_1p,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba_1p
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_1p,
0f6f042c-429c-4cee-8107-0fe99108f4a8_1p,
860ce808-4495-4d78-a786-45a79cec9a0e_1p,
38791220-517f-458a-90fd-65a0b062aa0a_1p,
86c36e81-5851-4074-b515-aed4262a971d_1p
result, different session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_1p,
0f6f042c-429c-4cee-8107-0fe99108f4a8_1p,
860ce808-4495-4d78-a786-45a79cec9a0e_1p,
38791220-517f-458a-90fd-65a0b062aa0a_1p,
86c36e81-5851-4074-b515-aed4262a971d_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_1p,
49ecc7f2-486e-4ab7-a832-addb6a421887_1p,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_1p,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_1p,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_1p
result, different session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_1p,
49ecc7f2-486e-4ab7-a832-addb6a421887_1p,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_1p,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_1p,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
CSS cache
CSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.
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="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_24210213061130137,
fake_3900513326534789,
fake_29091956065713553,
fake_12791659843363368,
fake_6036678742166754
result, different session:
fake_24210213061130137,
fake_3900513326534789,
fake_29091956065713553,
fake_12791659843363368,
fake_6036678742166754
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_9692355377714101,
fake_29700469196034907,
fake_043858618634373236,
fake_1590346457398497,
fake_1214802293718873
result, different session:
fake_9692355377714101,
fake_29700469196034907,
fake_043858618634373236,
fake_1590346457398497,
fake_1214802293718873
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_9731600129904339,
fake_22691939105812975,
fake_06832533546312725,
fake_7731092035259983,
fake_13440649296196527
result, different session:
fake_9731600129904339,
fake_22691939105812975,
fake_06832533546312725,
fake_7731092035259983,
fake_13440649296196527
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_6686070326520137,
fake_23859116452630258,
fake_440933814895083,
fake_44211956429753396,
fake_09712908791251174
result, different session:
fake_6686070326520137,
fake_23859116452630258,
fake_440933814895083,
fake_44211956429753396,
fake_09712908791251174
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_9089758217097983,
fake_40680233293301327,
fake_34235792551965694,
fake_07118657302296283,
fake_7112150130259669
result, different session:
fake_9089758217097983,
fake_40680233293301327,
fake_34235792551965694,
fake_07118657302296283,
fake_7112150130259669
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_9573339271486825,
fake_4233691311208132,
fake_8746358701370669,
fake_6921047552011241,
fake_5709034389926191
result, different session:
fake_646250473757974,
fake_7907884327044583,
fake_13751159829799953,
fake_8164952664969118,
fake_3180437823782103
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_2043284042665805,
fake_37041844934386714,
fake_25420964594125994,
fake_7740831942215993,
fake_6452475255188153
result, different session:
fake_2043284042665805,
fake_37041844934386714,
fake_25420964594125994,
fake_7740831942215993,
fake_6452475255188153
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_9418515412439534,
fake_752759070782764,
fake_13996491225325403,
fake_6659204756813664,
fake_9160552825877963
result, different session:
fake_9418515412439534,
fake_752759070782764,
fake_13996491225325403,
fake_6659204756813664,
fake_9160552825877963
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
favicon cache
A favicon is an icon that represents a website, typically shown in browser tab and bookmarks menu. If the favicon cache is not partitioned, it can be used to track users across websites.
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Unsupported
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Unsupported
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
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) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 2, 2, 2, 2, 2
result, different session: 3, 3, 3, 3, 3
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
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) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
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) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
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) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
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:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_1p,
c2a5940f-425e-422d-94f9-135afd1fa5ea_1p,
57cd9660-8597-4dd5-8ead-d9990f4ed669_1p,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_1p,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_1p
result, different session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_1p,
c2a5940f-425e-422d-94f9-135afd1fa5ea_1p,
57cd9660-8597-4dd5-8ead-d9990f4ed669_1p,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_1p,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_1p,
95b5d526-459c-4275-9c03-8eaab6524d00_1p,
b94f8b75-f692-4a74-be67-2d129ee968fa_1p,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_1p,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_1p
result, different session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_1p,
95b5d526-459c-4275-9c03-8eaab6524d00_1p,
b94f8b75-f692-4a74-be67-2d129ee968fa_1p,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_1p,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
671d85f5-2fe2-4980-b513-c2f951b1388f_1p,
19f09c1b-70dc-49ff-89db-7b0581136a7f_1p,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_1p,
ffce8953-f69a-4566-9acb-9eafce986a0e_1p,
f68151b8-82c0-4851-9c11-5e979d40d969_1p
result, different session:
671d85f5-2fe2-4980-b513-c2f951b1388f_1p,
19f09c1b-70dc-49ff-89db-7b0581136a7f_1p,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_1p,
ffce8953-f69a-4566-9acb-9eafce986a0e_1p,
f68151b8-82c0-4851-9c11-5e979d40d969_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_1p,
c50594c9-46ea-4084-a075-e3dd6f8cefff_1p,
374de0a5-76f5-453d-a8e7-6381fc3a060e_1p,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_1p,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_1p
result, different session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_1p,
c50594c9-46ea-4084-a075-e3dd6f8cefff_1p,
374de0a5-76f5-453d-a8e7-6381fc3a060e_1p,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_1p,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
500f9151-21f8-4127-8879-e18e11248a6f_1p,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_1p,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_1p,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_1p,
3e929897-9320-4cef-a12a-6563e2c86cb2_1p
result, different session:
500f9151-21f8-4127-8879-e18e11248a6f_1p,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_1p,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_1p,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_1p,
3e929897-9320-4cef-a12a-6563e2c86cb2_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
69cadac6-f50d-4990-8e84-00bb2148b1b4_1p,
e2db4657-3148-411b-aa92-1013549daecf_1p,
840f0ae2-df03-4b37-bb48-b3bda8ac4698_1p,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27_1p,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba_1p
result, different session: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_1p,
0f6f042c-429c-4cee-8107-0fe99108f4a8_1p,
860ce808-4495-4d78-a786-45a79cec9a0e_1p,
38791220-517f-458a-90fd-65a0b062aa0a_1p,
86c36e81-5851-4074-b515-aed4262a971d_1p
result, different session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_1p,
0f6f042c-429c-4cee-8107-0fe99108f4a8_1p,
860ce808-4495-4d78-a786-45a79cec9a0e_1p,
38791220-517f-458a-90fd-65a0b062aa0a_1p,
86c36e81-5851-4074-b515-aed4262a971d_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_1p,
49ecc7f2-486e-4ab7-a832-addb6a421887_1p,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_1p,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_1p,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_1p
result, different session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_1p,
49ecc7f2-486e-4ab7-a832-addb6a421887_1p,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_1p,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_1p,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
localStorage
The localStorage API gives websites access to a key-value database that will remain available across visits. If the localStorage API is not partitioned or blocked, it can also be used to track users across websites.
Failed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_1p,
c2a5940f-425e-422d-94f9-135afd1fa5ea_1p,
57cd9660-8597-4dd5-8ead-d9990f4ed669_1p,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_1p,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_1p
result, different session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_1p,
c2a5940f-425e-422d-94f9-135afd1fa5ea_1p,
57cd9660-8597-4dd5-8ead-d9990f4ed669_1p,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_1p,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_1p,
95b5d526-459c-4275-9c03-8eaab6524d00_1p,
b94f8b75-f692-4a74-be67-2d129ee968fa_1p,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_1p,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_1p
result, different session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_1p,
95b5d526-459c-4275-9c03-8eaab6524d00_1p,
b94f8b75-f692-4a74-be67-2d129ee968fa_1p,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_1p,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
671d85f5-2fe2-4980-b513-c2f951b1388f_1p,
19f09c1b-70dc-49ff-89db-7b0581136a7f_1p,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_1p,
ffce8953-f69a-4566-9acb-9eafce986a0e_1p,
f68151b8-82c0-4851-9c11-5e979d40d969_1p
result, different session:
671d85f5-2fe2-4980-b513-c2f951b1388f_1p,
19f09c1b-70dc-49ff-89db-7b0581136a7f_1p,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_1p,
ffce8953-f69a-4566-9acb-9eafce986a0e_1p,
f68151b8-82c0-4851-9c11-5e979d40d969_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_1p,
c50594c9-46ea-4084-a075-e3dd6f8cefff_1p,
374de0a5-76f5-453d-a8e7-6381fc3a060e_1p,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_1p,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_1p
result, different session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_1p,
c50594c9-46ea-4084-a075-e3dd6f8cefff_1p,
374de0a5-76f5-453d-a8e7-6381fc3a060e_1p,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_1p,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
500f9151-21f8-4127-8879-e18e11248a6f_1p,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_1p,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_1p,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_1p,
3e929897-9320-4cef-a12a-6563e2c86cb2_1p
result, different session:
500f9151-21f8-4127-8879-e18e11248a6f_1p,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_1p,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_1p,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_1p,
3e929897-9320-4cef-a12a-6563e2c86cb2_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
69cadac6-f50d-4990-8e84-00bb2148b1b4_1p,
e2db4657-3148-411b-aa92-1013549daecf_1p,
840f0ae2-df03-4b37-bb48-b3bda8ac4698_1p,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27_1p,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba_1p
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_1p,
0f6f042c-429c-4cee-8107-0fe99108f4a8_1p,
860ce808-4495-4d78-a786-45a79cec9a0e_1p,
38791220-517f-458a-90fd-65a0b062aa0a_1p,
86c36e81-5851-4074-b515-aed4262a971d_1p
result, different session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_1p,
0f6f042c-429c-4cee-8107-0fe99108f4a8_1p,
860ce808-4495-4d78-a786-45a79cec9a0e_1p,
38791220-517f-458a-90fd-65a0b062aa0a_1p,
86c36e81-5851-4074-b515-aed4262a971d_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_1p,
49ecc7f2-486e-4ab7-a832-addb6a421887_1p,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_1p,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_1p,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_1p
result, different session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_1p,
49ecc7f2-486e-4ab7-a832-addb6a421887_1p,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_1p,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_1p,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_1p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
prefetch cache
A <link rel='prefetch'...> suggests to browsers they should fetch a resource ahead of time and cache it. But if browsers don't partition this cache, it can be used to track users across websites.
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
XMLHttpRequest cache
Similar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
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.
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h2, h2, h2, h2, h2
result, different session: h2, h2, h2, h2, h2
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h2, h2, h2, h2, h2
result, different session: h2, h2, h2, h2, h2
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h2, h2, h2, h2, h2
result, different session: h2, h2, h2, h2, h2
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h2, h2, h2, h2, h2
result, different session: h2, h2, h2, h2, h2
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h2, h2, h2, h2, h2
result, different session: h2, h2, h2, h2, h2
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h2, h2, h2, h2, h2
result, different session: h2, h2, h2, h2, h2
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h2, h2, h2, h2, h2
result, different session: h2, h2, h2, h2, h2
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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(window.location)).searchParams.get('thirdparty') === 'same') {
          if (protocol !== 'h3') {
            throw new Error('Unsupported');
          }
        }
        return protocol;
      }
result, same session: h2, h2, h2, h2, h2
result, different session: h2, h2, h2, h2, h2
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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 {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_3p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_3p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_3p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_3p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_3p
result, different session:
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_3p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_3p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_3p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_3p,
0b3fbdeb-137d-44c4-a93b-4ab8c9ae4f56_3p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
3896d4ce-c55d-4bf1-ae02-9cee2145850c_3p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_3p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_3p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_3p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_3p
result, different session:
3896d4ce-c55d-4bf1-ae02-9cee2145850c_3p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_3p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_3p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_3p,
3896d4ce-c55d-4bf1-ae02-9cee2145850c_3p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
5f0f614c-43fc-420e-944b-4f0a0da990bf_3p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_3p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_3p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_3p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_3p
result, different session:
5f0f614c-43fc-420e-944b-4f0a0da990bf_3p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_3p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_3p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_3p,
5f0f614c-43fc-420e-944b-4f0a0da990bf_3p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
c30feb74-0688-4e93-a1ee-945a342e2e51_3p,
c30feb74-0688-4e93-a1ee-945a342e2e51_3p,
c30feb74-0688-4e93-a1ee-945a342e2e51_3p,
c30feb74-0688-4e93-a1ee-945a342e2e51_3p,
c30feb74-0688-4e93-a1ee-945a342e2e51_3p
result, different session:
c30feb74-0688-4e93-a1ee-945a342e2e51_3p,
c30feb74-0688-4e93-a1ee-945a342e2e51_3p,
c30feb74-0688-4e93-a1ee-945a342e2e51_3p,
c30feb74-0688-4e93-a1ee-945a342e2e51_3p,
c30feb74-0688-4e93-a1ee-945a342e2e51_3p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
a3efc9cf-e003-4db6-b541-110fd75a7184_3p,
a3efc9cf-e003-4db6-b541-110fd75a7184_3p,
a3efc9cf-e003-4db6-b541-110fd75a7184_3p,
a3efc9cf-e003-4db6-b541-110fd75a7184_3p,
a3efc9cf-e003-4db6-b541-110fd75a7184_3p
result, different session:
a3efc9cf-e003-4db6-b541-110fd75a7184_3p,
a3efc9cf-e003-4db6-b541-110fd75a7184_3p,
a3efc9cf-e003-4db6-b541-110fd75a7184_3p,
a3efc9cf-e003-4db6-b541-110fd75a7184_3p,
a3efc9cf-e003-4db6-b541-110fd75a7184_3p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
result, different session:
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url'),
Error: undefined is not an object (evaluating 'cacheKeys[0].url')
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
4301548a-9fe6-46c1-bab3-6eca1e419c61_3p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_3p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_3p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_3p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_3p
result, different session:
4301548a-9fe6-46c1-bab3-6eca1e419c61_3p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_3p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_3p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_3p,
4301548a-9fe6-46c1-bab3-6eca1e419c61_3p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        try {
          const cache = await window.caches.open('supercookies');
          cache.addAll([`test.css?key=${key}`]);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: async () => {
        const cache = await window.caches.open('supercookies');
        const cacheKeys = await cache.keys();
        const url = cacheKeys[0].url;
        return (new URL(url)).searchParams.get('key');
      }
result, same session:
e2799d44-532c-43fe-aee3-305e020ebb55_3p,
e2799d44-532c-43fe-aee3-305e020ebb55_3p,
e2799d44-532c-43fe-aee3-305e020ebb55_3p,
e2799d44-532c-43fe-aee3-305e020ebb55_3p,
e2799d44-532c-43fe-aee3-305e020ebb55_3p
result, different session:
e2799d44-532c-43fe-aee3-305e020ebb55_3p,
e2799d44-532c-43fe-aee3-305e020ebb55_3p,
e2799d44-532c-43fe-aee3-305e020ebb55_3p,
e2799d44-532c-43fe-aee3-305e020ebb55_3p,
e2799d44-532c-43fe-aee3-305e020ebb55_3p
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
cookie (HTTP)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (secret) => {
      // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value.
        await fetch(`${baseURI}cookie?secret=${secret}_http`);
      }
read: async () => {
      // Test if we now send a requests with a 'cookie' header containing the secret.
        const response = await fetch(`${baseURI}headers`);
        const cookie = (await response.json()).cookie;
        return cookie ? cookie.match(/secret=([\w-]+)/)[1] : null;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
cookie (JS)
The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
Unsupported
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (secret) => {
        document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`;
      }
read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
CookieStore
The Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.
Unsupported
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session: , , , ,
result, different session:
Error: Type error,
Error: Type error,
Error: Type error,
Error: Type error,
Error: Type error
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (data) => {
        const msPerHour = 60 * 60 * 1000;
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        window.cookieStore.set({
          name: 'partition_test',
          value: data,
          expires: Date.now() + msPerHour,
          sameSite: 'none'
        });
      }
read: async () => {
        if (!window.cookieStore) {
          throw new Error('Unsupported');
        }
        const cookie = await window.cookieStore.get('partition_test');
        if (!cookie) {
          return null;
        }
        return cookie.value;
      }
result, same session: , , , ,
result, different session: , , , ,
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
CSS cache
CSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.
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="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_0009045926163346873,
fake_3325330325703888,
fake_3782744326100669,
fake_8210657889513688,
fake_10338093736736864
result, different session:
fake_0009045926163346873,
fake_3325330325703888,
fake_3782744326100669,
fake_8210657889513688,
fake_10338093736736864
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_9469458160271083,
fake_22783221495552453,
fake_6847347740722243,
fake_15790548482288713,
fake_1547230389741825
result, different session:
fake_9469458160271083,
fake_22783221495552453,
fake_6847347740722243,
fake_15790548482288713,
fake_1547230389741825
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_7289283372235669,
fake_41020138250057103,
fake_9326944617801827,
fake_05455320469304836,
fake_37903124916531117
result, different session:
fake_7289283372235669,
fake_41020138250057103,
fake_9326944617801827,
fake_05455320469304836,
fake_37903124916531117
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_7489702558760514,
fake_6913559917571006,
fake_23125244531031908,
fake_285256351293272,
fake_22417739831214356
result, different session:
fake_7489702558760514,
fake_6913559917571006,
fake_23125244531031908,
fake_285256351293272,
fake_22417739831214356
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_5159112339510563,
fake_42517437876249664,
fake_22838656337593433,
fake_11418323724933255,
fake_6760769265725133
result, different session:
fake_5159112339510563,
fake_42517437876249664,
fake_22838656337593433,
fake_11418323724933255,
fake_6760769265725133
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_29383368906382445,
fake_1234106509284465,
fake_3364107134911736,
fake_08763156513260095,
fake_8482792069976213
result, different session:
fake_11574661639299455,
fake_5403158635092951,
fake_4249273414014627,
fake_017340949912036274,
fake_8700643813380893
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_9880848569403924,
fake_9752375133741482,
fake_6887013472854635,
fake_9545620265808727,
fake_5193897454795955
result, different session:
fake_9880848569403924,
fake_9752375133741482,
fake_6887013472854635,
fake_9545620265808727,
fake_5193897454795955
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return key;
      }
read: async (key) => {
        const href = testURI('resource', 'css', key);
        const head = document.getElementsByTagName('head')[0];
        head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`;
        const testElement = document.querySelector('#css');
        let fontFamily;
        while (true) {
          await sleepMs(100);
          fontFamily = window.getComputedStyle(testElement).fontFamily;
          if (fontFamily.startsWith('fake')) {
            break;
          }
        }
        console.log(fontFamily);
        return fontFamily;
      }
result, same session:
fake_633049007022717,
fake_42801133200926444,
fake_6592189487825779,
fake_18454617298858822,
fake_18543707733846193
result, different session:
fake_633049007022717,
fake_42801133200926444,
fake_6592189487825779,
fake_18454617298858822,
fake_18543707733846193
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
favicon cache
A favicon is an icon that represents a website, typically shown in browser tab and bookmarks menu. If the favicon cache is not partitioned, it can be used to track users across websites.
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Unsupported
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Unsupported
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => key
read: async (key) => {
      // Wait for the favicon to load (defined in supercookies.html)
        await sleepMs(2000);
        const response = await fetch(
          testURI('ctr', 'favicon', key), { cache: 'reload' });
        const count = (await response.text()).trim();
        if (count === '0') {
          throw new Error('No requests received');
        }
        return count;
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
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) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 2, 2, 2, 2, 2
result, different session: 3, 3, 3, 3, 3
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        return key;
      }
read: async (key) => {
        await fetch(testURI('resource', 'fetch', key),
          { cache: 'force-cache' });
        const countResponse = await fetch(testURI('ctr', 'fetch', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
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) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`;
        document.getElementsByTagName('head')[0].appendChild(style);
        return key;
      }
read: async (key) => {
        const text = document.createElement('span');
        text.id = 'text';
        text.innerText = 'test';
        document.body.appendChild(text);
        const originalWidth = text.getBoundingClientRect().width;
        const style = document.createElement('style');
        style.type = 'text/css';
        const fontURI = testURI('resource', 'font', key);
        style.innerHTML = `@font-face {font-family: "myFont"; src: url("${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);
        const response = await fetch(
          testURI('ctr', 'font', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
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) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        iframe.addEventListener('load', () => resolve(key), { once: true });
        iframe.src = testURI('resource', 'page', key);
      })
read: async (key) => {
        const iframe = document.createElement('iframe');
        document.body.appendChild(iframe);
        const iframeLoadPromise = new Promise((resolve, reject) => {
          iframe.addEventListener('load', resolve, { once: true });
        });
        const address = testURI('resource', 'page', key);
        iframe.src = address;
        await iframeLoadPromise;
        const response = await fetch(
          testURI('ctr', 'page', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
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) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        img.addEventListener('load', () => resolve(key), { once: true });
        img.src = testURI('resource', 'image', key);
      })
read: async (key) => {
        const img = document.createElement('img');
        document.body.appendChild(img);
        const imgLoadPromise = new Promise((resolve, reject) => {
          img.addEventListener('load', resolve, { once: true });
        });
        img.src = testURI('resource', 'image', key);
        await imgLoadPromise;
        const response = await fetch(
          testURI('ctr', 'image', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
indexedDB
The IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_3p,
c2a5940f-425e-422d-94f9-135afd1fa5ea_3p,
57cd9660-8597-4dd5-8ead-d9990f4ed669_3p,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_3p,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_3p
result, different session: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_3p,
95b5d526-459c-4275-9c03-8eaab6524d00_3p,
b94f8b75-f692-4a74-be67-2d129ee968fa_3p,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_3p,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_3p
result, different session: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
671d85f5-2fe2-4980-b513-c2f951b1388f_3p,
19f09c1b-70dc-49ff-89db-7b0581136a7f_3p,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_3p,
ffce8953-f69a-4566-9acb-9eafce986a0e_3p,
f68151b8-82c0-4851-9c11-5e979d40d969_3p
result, different session: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_3p,
c50594c9-46ea-4084-a075-e3dd6f8cefff_3p,
374de0a5-76f5-453d-a8e7-6381fc3a060e_3p,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_3p,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_3p
result, different session: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
500f9151-21f8-4127-8879-e18e11248a6f_3p,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_3p,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_3p,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_3p,
3e929897-9320-4cef-a12a-6563e2c86cb2_3p
result, different session: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
69cadac6-f50d-4990-8e84-00bb2148b1b4_3p,
e2db4657-3148-411b-aa92-1013549daecf_3p,
840f0ae2-df03-4b37-bb48-b3bda8ac4698_3p,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27_3p,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba_3p
result, different session: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_3p,
0f6f042c-429c-4cee-8107-0fe99108f4a8_3p,
860ce808-4495-4d78-a786-45a79cec9a0e_3p,
38791220-517f-458a-90fd-65a0b062aa0a_3p,
86c36e81-5851-4074-b515-aed4262a971d_3p
result, different session: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: async (secret) => {
        try {
          return await IdbKeyVal.set('secret', secret);
        } catch (e) {
          throw new Error('Unsupported');
        }
      }
read: () => IdbKeyVal.get('secret')
result, same session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_3p,
49ecc7f2-486e-4ab7-a832-addb6a421887_3p,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_3p,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_3p,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_3p
result, different session: undefined
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
localStorage
The localStorage API gives websites access to a key-value database that will remain available across visits. If the localStorage API is not partitioned or blocked, it can also be used to track users across websites.
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
3d75ac7a-302f-4fa5-be9c-4f10e9a483c9_3p,
c2a5940f-425e-422d-94f9-135afd1fa5ea_3p,
57cd9660-8597-4dd5-8ead-d9990f4ed669_3p,
7a2fd1a9-5514-426a-9836-5d3de3ede32e_3p,
ea2f8458-a4f3-4fb6-a26e-8d8bbbbaa1ab_3p
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
baef3f1a-5eb8-4825-84b3-1a351cd4f946_3p,
95b5d526-459c-4275-9c03-8eaab6524d00_3p,
b94f8b75-f692-4a74-be67-2d129ee968fa_3p,
ef19b766-fc54-4893-9a7d-487b7b3fc8d2_3p,
ee56bc51-9b8c-47d9-9e35-3f115c8f0adc_3p
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
671d85f5-2fe2-4980-b513-c2f951b1388f_3p,
19f09c1b-70dc-49ff-89db-7b0581136a7f_3p,
46e1edd3-9d95-48b2-95d2-72f092fd6a60_3p,
ffce8953-f69a-4566-9acb-9eafce986a0e_3p,
f68151b8-82c0-4851-9c11-5e979d40d969_3p
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
83d6a8f8-afe7-4353-abc9-ab9fa4a92b8c_3p,
c50594c9-46ea-4084-a075-e3dd6f8cefff_3p,
374de0a5-76f5-453d-a8e7-6381fc3a060e_3p,
d198c262-2a2e-45e7-b5b1-20c1c6e3c1a1_3p,
1f02f498-5031-4d2b-95bb-15e87a1e27dd_3p
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
500f9151-21f8-4127-8879-e18e11248a6f_3p,
75dce9f1-1f55-48a6-98a8-d37a3f5bef9f_3p,
e2a80b15-91bb-43cd-b500-f80f6abd55f8_3p,
d62ff542-078b-452c-a3f0-eb1b0b4b8247_3p,
3e929897-9320-4cef-a12a-6563e2c86cb2_3p
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
69cadac6-f50d-4990-8e84-00bb2148b1b4_3p,
e2db4657-3148-411b-aa92-1013549daecf_3p,
840f0ae2-df03-4b37-bb48-b3bda8ac4698_3p,
9dce40b8-d7a2-4805-959f-d9b0aa39ca27_3p,
d4418a02-81c8-41d1-93b7-2ca9f2e677ba_3p
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
aa3860ea-4a49-454f-8472-b9de28cf07b4_3p,
0f6f042c-429c-4cee-8107-0fe99108f4a8_3p,
860ce808-4495-4d78-a786-45a79cec9a0e_3p,
38791220-517f-458a-90fd-65a0b062aa0a_3p,
86c36e81-5851-4074-b515-aed4262a971d_3p
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Passed
write: (secret) => { window.localStorage.setItem('secret', secret); }
read: () => window.localStorage.getItem('secret')
result, same session:
d25496fb-946c-4b2c-918c-c34c3ef0213a_3p,
49ecc7f2-486e-4ab7-a832-addb6a421887_3p,
019595da-6f6c-41ef-b1f1-2fc0aece4fec_3p,
691eb37e-8f1e-4fa1-a652-69d8928d3cec_3p,
00c1f48b-e6be-47b9-9c44-dd5281945dc2_3p
result, different session: , , , ,
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
prefetch cache
A <link rel='prefetch'...> suggests to browsers they should fetch a resource ahead of time and cache it. But if browsers don't partition this cache, it can be used to track users across websites.
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
Unsupported
write: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        return key;
      }
read: async (key) => {
        const link = document.createElement('link');
        link.rel = 'prefetch';
        link.href = testURI('resource', 'prefetch', key);
        document.getElementsByTagName('head')[0].appendChild(link);
        await sleepMs(500);
        const response = await fetch(
          testURI('ctr', 'prefetch', key), { cache: 'reload' });
        const countString = (await response.text()).trim();
        if (parseInt(countString) === 0) {
          throw new Error('No requests received');
        }
        return countString;
      }
result, same session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
result, different session:
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received,
Error: No requests received
unsupported: true, true, true, true, true
passed: undefined
test failed: false, false, false, false, false
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) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: (key) => new Promise((resolve, reject) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        script.addEventListener('load', () => resolve(key), { once: true });
        script.src = testURI('resource', 'script', key);
      })
read: async (key) => {
        const script = document.createElement('script');
        document.body.appendChild(script);
        const scriptLoadPromise = new Promise((resolve, reject) => {
          script.addEventListener('load', resolve, { once: true });
        });
        script.src = testURI('resource', 'script', key);
        await scriptLoadPromise;
        const response = await fetch(
          testURI('ctr', 'script', key), { cache: 'reload' });
        return (await response.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
XMLHttpRequest cache
Similar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Passed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 2, 2, 2, 2, 2
unsupported: false, false, false, false, false
passed: true, true, true, true, true
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false
Failed
write: async (key) => {
        const req = new window.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 window.XMLHttpRequest();
        const loadPromise = new Promise(resolve => req.addEventListener('load', resolve));
        req.open('GET', testURI('resource', 'xhr', key));
        req.send();
        await loadPromise;
        const countResponse = await fetch(testURI('ctr', 'xhr', key),
          { cache: 'reload' });
        return (await countResponse.text()).trim();
      }
result, same session: 1, 1, 1, 1, 1
result, different session: 1, 1, 1, 1, 1
unsupported: false, false, false, false, false
passed: false, false, false, false, false
test failed: false, false, false, false, false