Desktop private modes

(default settings)

brave
1.57

private

chrome
116.0

private

edge
116.0

private

firefox
116.0

private

librewolf
116.0

private

mullvad
12.5

private

opera
101.0

private

safari
16.6

private

tor
12.5

private

ungoogled
115.0

private

vivaldi
6.1

private
State Partitioning tests Which 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-SvcAlt-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.
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Load failed, h2, Error: Load failed, Error: Load failed unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
blobA 'blob URL' is a local reference to some raw data. Trackers can use a blob URL to share data between websites.
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: Error: Failed to fetch, Error: Failed to fetch, Error: Failed to fetch, Error: Failed to fetch unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9, 2c6f0997-321a-4990-98e3-9bed415fdfab, a0f5c861-68a9-4067-912e-e3ac29777cfe, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186 result, different first party: 9915b131-e392-4f54-b0b0-10a779442cd9, 2c6f0997-321a-4990-98e3-9bed415fdfab, a0f5c861-68a9-4067-912e-e3ac29777cfe, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 1627bda0-b530-4117-8513-ed73801416d1, 968ea873-db17-4bf2-be9d-341c797feae5, 4156389a-5349-4c89-8b67-8f62b9932e06, 418fa667-dc9d-41db-807c-d08a0ae12221 result, different first party: 1627bda0-b530-4117-8513-ed73801416d1, 968ea873-db17-4bf2-be9d-341c797feae5, 4156389a-5349-4c89-8b67-8f62b9932e06, 418fa667-dc9d-41db-807c-d08a0ae12221 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: b2e80bd9-c5cc-4808-b316-200e35e0a990, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3, 46b41978-e872-4efc-aa6a-4087cd8587d8 result, different first party: Error: NetworkError when attempting to fetch resource., Error: NetworkError when attempting to fetch resource., Error: NetworkError when attempting to fetch resource., Error: NetworkError when attempting to fetch resource. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: Error: Load failed, 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 unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 0e46c989-a36b-4473-b145-4d119e50d1b3, f67c8512-8836-4bb8-aa5a-29e094c3eca8, 3a3b164e-50cd-4baf-b2e8-e8375f83b300, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469 result, different first party: Error: NetworkError when attempting to fetch resource., Error: NetworkError when attempting to fetch resource., Error: NetworkError when attempting to fetch resource., Error: NetworkError when attempting to fetch resource. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${baseURI}blob?mode=write&key=${secret}&blobUrl=${encodeURIComponent(blobURL)}`); } catch (e) { throw new Error("Unsupported"); } } read: async (secret) => { let response = await fetch(`${baseURI}blob?mode=read&key=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
BroadcastChannelA BroadcastChannel is designed to send messages between tabs. In some browsers it can be used for cross-site communication and tracking.
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9, 2c6f0997-321a-4990-98e3-9bed415fdfab, a0f5c861-68a9-4067-912e-e3ac29777cfe, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186 result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: 1627bda0-b530-4117-8513-ed73801416d1, 968ea873-db17-4bf2-be9d-341c797feae5, 4156389a-5349-4c89-8b67-8f62b9932e06, 418fa667-dc9d-41db-807c-d08a0ae12221 result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: b2e80bd9-c5cc-4808-b316-200e35e0a990, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3, 46b41978-e872-4efc-aa6a-4087cd8587d8 result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: 0e46c989-a36b-4473-b145-4d119e50d1b3, f67c8512-8836-4bb8-aa5a-29e094c3eca8, 3a3b164e-50cd-4baf-b2e8-e8375f83b300, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469 result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { try { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data === "request") { bc.postMessage(secret); } }; } catch (e) { throw new Error("Unsupported"); } } read: () => new Promise((resolve, reject) => { let bc = new BroadcastChannel("secrets"); bc.onmessage = (event) => { if (event.data !== "request") { resolve(event.data); } }; bc.postMessage("request"); setTimeout(() => reject({message: "no BroadcastChannel message"}), 3000); }) result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
CacheStorageThe 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.
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. unsupported: false, false, false, false passed: true, true, true, true test failed: 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.
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671_http, 3a97209b-1788-4386-a100-c1f080f208ed_http, 5220841f-fa5d-41c4-8328-9c0b0a79663c_http, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_http result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32_http, 53f6f750-08ee-4fff-9e9f-9727a6546c57_http, 67c74d28-b18c-480d-82a4-026d6c7113dd_http, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9_http result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_http, 60422fe9-a24b-4999-b491-7ab178c79ad3_http, 5fc445e2-97c0-406e-b955-2cf486b66d02_http, f55fb1ed-8d31-46a3-a27f-4c03925b604e_http result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_http, 60422fe9-a24b-4999-b491-7ab178c79ad3_http, 5fc445e2-97c0-406e-b955-2cf486b66d02_http, f55fb1ed-8d31-46a3-a27f-4c03925b604e_http unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9_http, 2c6f0997-321a-4990-98e3-9bed415fdfab_http, a0f5c861-68a9-4067-912e-e3ac29777cfe_http, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186_http result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 1627bda0-b530-4117-8513-ed73801416d1_http, 968ea873-db17-4bf2-be9d-341c797feae5_http, 4156389a-5349-4c89-8b67-8f62b9932e06_http, 418fa667-dc9d-41db-807c-d08a0ae12221_http result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: b2e80bd9-c5cc-4808-b316-200e35e0a990_http, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5_http, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3_http, 46b41978-e872-4efc-aa6a-4087cd8587d8_http result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990_http, 486753ac-5ee1-4845-914e-b4d447cdd0d9_http, 7cd6bf02-0547-450d-8c9c-6ce3a6470342_http, 919dfb09-a069-466e-a150-77755c21db77_http result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: , , , result, different first party: , , , unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 0e46c989-a36b-4473-b145-4d119e50d1b3_http, f67c8512-8836-4bb8-aa5a-29e094c3eca8_http, 3a3b164e-50cd-4baf-b2e8-e8375f83b300_http, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469_http result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7_http, 788cdb07-a775-4451-a85f-b542851f8a4c_http, 39ca5981-befe-4339-a896-569a4c66ad80_http, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4_http result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2_http, 913a2832-170f-4e90-854d-7280946144ab_http, c28a7953-008f-4fa5-8e15-12750255bf16_http, 00124808-29a4-4b8b-9477-b17c1f0fcac4_http result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
cookie (JS)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671_js, 3a97209b-1788-4386-a100-c1f080f208ed_js, 5220841f-fa5d-41c4-8328-9c0b0a79663c_js, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_js result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32_js, 53f6f750-08ee-4fff-9e9f-9727a6546c57_js, 67c74d28-b18c-480d-82a4-026d6c7113dd_js, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9_js result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_js, 60422fe9-a24b-4999-b491-7ab178c79ad3_js, 5fc445e2-97c0-406e-b955-2cf486b66d02_js, f55fb1ed-8d31-46a3-a27f-4c03925b604e_js result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_js, 60422fe9-a24b-4999-b491-7ab178c79ad3_js, 5fc445e2-97c0-406e-b955-2cf486b66d02_js, f55fb1ed-8d31-46a3-a27f-4c03925b604e_js unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9_js, 2c6f0997-321a-4990-98e3-9bed415fdfab_js, a0f5c861-68a9-4067-912e-e3ac29777cfe_js, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186_js result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 1627bda0-b530-4117-8513-ed73801416d1_js, 968ea873-db17-4bf2-be9d-341c797feae5_js, 4156389a-5349-4c89-8b67-8f62b9932e06_js, 418fa667-dc9d-41db-807c-d08a0ae12221_js result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: b2e80bd9-c5cc-4808-b316-200e35e0a990_js, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5_js, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3_js, 46b41978-e872-4efc-aa6a-4087cd8587d8_js result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990_js, 486753ac-5ee1-4845-914e-b4d447cdd0d9_js, 7cd6bf02-0547-450d-8c9c-6ce3a6470342_js, 919dfb09-a069-466e-a150-77755c21db77_js result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: , , , result, different first party: , , , unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 0e46c989-a36b-4473-b145-4d119e50d1b3_js, f67c8512-8836-4bb8-aa5a-29e094c3eca8_js, 3a3b164e-50cd-4baf-b2e8-e8375f83b300_js, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469_js result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7_js, 788cdb07-a775-4451-a85f-b542851f8a4c_js, 39ca5981-befe-4339-a896-569a4c66ad80_js, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4_js result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2_js, 913a2832-170f-4e90-854d-7280946144ab_js, c28a7953-008f-4fa5-8e15-12750255bf16_js, 00124808-29a4-4b8b-9477-b17c1f0fcac4_js result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
CookieStoreThe Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.
  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: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  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: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  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: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  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: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  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: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  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: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
CSS cacheCSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_7720539464867167, fake_1585239523802353, fake_3871247124550157, fake_20647521153019266 result, different first party: fake_8000467565716598, fake_9538913916512071, fake_43969219298409756, fake_5873833433827331 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_3379168320814483, fake_4066984561345579, fake_7314718651271839, fake_6169996980212678 result, different first party: fake_3379168320814483, fake_4066984561345579, fake_7314718651271839, fake_6169996980212678 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_037201956972738204, fake_4882191346737117, fake_5364792181370548, fake_8569415509450371 result, different first party: fake_037201956972738204, fake_4882191346737117, fake_5364792181370548, fake_8569415509450371 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_7381976997689632, fake_3463585925671948, fake_7804119319428373, fake_4693380673257981 result, different first party: fake_12569404847250687, fake_3925856742490641, fake_41919629399949754, fake_9018807528774895 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_5867485361076121, fake_18991721044611243, fake_5493649740666195, fake_9302321508210076 result, different first party: fake_09639662763091272, fake_25979629880241206, fake_8054792553594732, fake_5294082158053701 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_9636672345372101, fake_19198061953423995, fake_5202376217408837, fake_024463922414357686 result, different first party: fake_5211338951864934, fake_43666086556611794, fake_8104222096411708, fake_9349158538689839 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_6441092353497926, fake_5471950771741656, fake_9080103689204426, fake_9951301838732844 result, different first party: fake_6441092353497926, fake_5471950771741656, fake_9080103689204426, fake_9951301838732844 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_09214881616150095, fake_8745006744031563, fake_48247954263152804, fake_9201383708721724 result, different first party: fake_01433613793800137, fake_42595217923264217, fake_3298682365992498, fake_05143686162966876 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_4193855172610008, fake_21874431500457248, fake_8086229142783181, fake_5665262339634096 result, different first party: fake_5920128381548624, fake_7450307136695618, fake_630210010464044, fake_7833830586606754 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_14506177173436874, fake_8414142115785443, fake_6410503395325657, fake_8959973572256419 result, different first party: fake_14506177173436874, fake_8414142115785443, fake_6410503395325657, fake_8959973572256419 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same first party: fake_145865180331765, fake_12456244586069909, fake_6248778914467201, fake_4521658668858446 result, different first party: fake_145865180331765, fake_12456244586069909, fake_6248778914467201, fake_4521658668858446 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
favicon cacheA 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.
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 2, 2, 2, 2 result, different first party: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
fetch cacheWhen a resource is received via the Fetch API, it is frequently cached. That cache can potentially be abused for cross-site tracking.
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 2, 2, 2, 2 result, different first party: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
font cacheWeb fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2, 2, 2, 2 result, different first party: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
getDirectorynavigator.storage.getDirectory exposes a location for storing files to web content. In some cases, these files may be shared across tabs.
  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: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  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: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  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: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
write: async (secret) => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt", { create: true }); const stream = await fileHandle.createWritable(); await stream.write(secret); await stream.close(); } catch (e) { throw new Error("Unsupported"); } } read: async () => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt"); const file = await fileHandle.getFile(); return file.text(); } catch (e) { throw new Error("Unsupported"); } } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt", { create: true }); const stream = await fileHandle.createWritable(); await stream.write(secret); await stream.close(); } catch (e) { throw new Error("Unsupported"); } } read: async () => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt"); const file = await fileHandle.getFile(); return file.text(); } catch (e) { throw new Error("Unsupported"); } } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt", { create: true }); const stream = await fileHandle.createWritable(); await stream.write(secret); await stream.close(); } catch (e) { throw new Error("Unsupported"); } } read: async () => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt"); const file = await fileHandle.getFile(); return file.text(); } catch (e) { throw new Error("Unsupported"); } } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  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: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (secret) => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt", { create: true }); const stream = await fileHandle.createWritable(); await stream.write(secret); await stream.close(); } catch (e) { throw new Error("Unsupported"); } } read: async () => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt"); const file = await fileHandle.getFile(); return file.text(); } catch (e) { throw new Error("Unsupported"); } } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt", { create: true }); const stream = await fileHandle.createWritable(); await stream.write(secret); await stream.close(); } catch (e) { throw new Error("Unsupported"); } } read: async () => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt"); const file = await fileHandle.getFile(); return file.text(); } catch (e) { throw new Error("Unsupported"); } } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  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: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  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: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
H1 connectionHTTP/1.x are the classic web connection protocols. If these connections are re-used across websites, they can be used to track users.
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9, 2c6f0997-321a-4990-98e3-9bed415fdfab, a0f5c861-68a9-4067-912e-e3ac29777cfe, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 1627bda0-b530-4117-8513-ed73801416d1, 968ea873-db17-4bf2-be9d-341c797feae5, 4156389a-5349-4c89-8b67-8f62b9932e06, 418fa667-dc9d-41db-807c-d08a0ae12221 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: b2e80bd9-c5cc-4808-b316-200e35e0a990, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3, 46b41978-e872-4efc-aa6a-4087cd8587d8 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 0e46c989-a36b-4473-b145-4d119e50d1b3, f67c8512-8836-4bb8-aa5a-29e094c3eca8, 3a3b164e-50cd-4baf-b2e8-e8375f83b300, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
H2 connectionHTTP/2 is a web connection protocol introduced in 2015. Some browsers re-use HTTP/2 connections across websites and can thus be used to track users.
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9, 2c6f0997-321a-4990-98e3-9bed415fdfab, a0f5c861-68a9-4067-912e-e3ac29777cfe, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 1627bda0-b530-4117-8513-ed73801416d1, 968ea873-db17-4bf2-be9d-341c797feae5, 4156389a-5349-4c89-8b67-8f62b9932e06, 418fa667-dc9d-41db-807c-d08a0ae12221 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: b2e80bd9-c5cc-4808-b316-200e35e0a990, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3, 46b41978-e872-4efc-aa6a-4087cd8587d8 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 0e46c989-a36b-4473-b145-4d119e50d1b3, f67c8512-8836-4bb8-aa5a-29e094c3eca8, 3a3b164e-50cd-4baf-b2e8-e8375f83b300, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
H3 connectionHTTP/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.
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
HSTS cacheThe 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."
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested result, different first party: Upgraded to https, Upgraded to https, Upgraded to https, Upgraded to https unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested result, different first party: Upgraded to https, Upgraded to https, Upgraded to https, Upgraded to https unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: null read: null result, same first party: , , , result, different first party: HTTPS used by default; no HSTS cache issue expected, HTTPS used by default; no HSTS cache issue expected, HTTPS used by default; no HSTS cache issue expected, HTTPS used by default; no HSTS cache issue expected unsupported: , , , passed: true, true, true, true test failed: false, false, false, false
  write: null read: null result, same first party: , , , result, different first party: HTTPS used by default; no HSTS cache issue expected, HTTPS used by default; no HSTS cache issue expected, HTTPS used by default; no HSTS cache issue expected, HTTPS used by default; no HSTS cache issue expected unsupported: , , , passed: true, true, true, true test failed: false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested result, different first party: Upgraded to https, Upgraded to https, Upgraded to https, Upgraded to https unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: null read: null result, same first party: , , , result, different first party: HTTPS used by default; no HSTS cache issue expected, HTTPS used by default; no HSTS cache issue expected, HTTPS used by default; no HSTS cache issue expected, HTTPS used by default; no HSTS cache issue expected unsupported: , , , passed: true, true, true, true test failed: false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested result, different first party: Upgraded to https, Upgraded to https, Upgraded to https, Upgraded to https unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested result, different first party: Upgraded to https, Upgraded to https, Upgraded to https, Upgraded to https unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
iframe cacheAn 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.
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2, 2, 2, 2 result, different first party: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
image cacheCaching of images in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2, 2, 2, 2 result, different first party: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
indexedDBThe IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9, 2c6f0997-321a-4990-98e3-9bed415fdfab, a0f5c861-68a9-4067-912e-e3ac29777cfe, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186 result, different first party: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: 1627bda0-b530-4117-8513-ed73801416d1, 968ea873-db17-4bf2-be9d-341c797feae5, 4156389a-5349-4c89-8b67-8f62b9932e06, 418fa667-dc9d-41db-807c-d08a0ae12221 result, different first party: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations. result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: undefined result, different first party: undefined unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations. result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
localStorageThe 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.
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9, 2c6f0997-321a-4990-98e3-9bed415fdfab, a0f5c861-68a9-4067-912e-e3ac29777cfe, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 1627bda0-b530-4117-8513-ed73801416d1, 968ea873-db17-4bf2-be9d-341c797feae5, 4156389a-5349-4c89-8b67-8f62b9932e06, 418fa667-dc9d-41db-807c-d08a0ae12221 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: b2e80bd9-c5cc-4808-b316-200e35e0a990, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3, 46b41978-e872-4efc-aa6a-4087cd8587d8 result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: , , , result, different first party: , , , unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 0e46c989-a36b-4473-b145-4d119e50d1b3, f67c8512-8836-4bb8-aa5a-29e094c3eca8, 3a3b164e-50cd-4baf-b2e8-e8375f83b300, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469 result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
locksnavigator.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.
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: Error: The request was denied., Error: The request was denied., Error: The request was denied., Error: The request was denied. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: Error: The request was denied., Error: The request was denied., Error: The request was denied., Error: The request was denied. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9, 2c6f0997-321a-4990-98e3-9bed415fdfab, a0f5c861-68a9-4067-912e-e3ac29777cfe, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186 result, different first party: Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: 1627bda0-b530-4117-8513-ed73801416d1, 968ea873-db17-4bf2-be9d-341c797feae5, 4156389a-5349-4c89-8b67-8f62b9932e06, 418fa667-dc9d-41db-807c-d08a0ae12221 result, different first party: Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: b2e80bd9-c5cc-4808-b316-200e35e0a990, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3, 46b41978-e872-4efc-aa6a-4087cd8587d8 result, different first party: Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: Error: The request was denied., Error: The request was denied., Error: The request was denied., Error: The request was denied. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), 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') unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: 0e46c989-a36b-4473-b145-4d119e50d1b3, f67c8512-8836-4bb8-aa5a-29e094c3eca8, 3a3b164e-50cd-4baf-b2e8-e8375f83b300, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469 result, different first party: Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context, Error: LockManager.query: query() is not allowed in this context unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: Error: The request was denied., Error: The request was denied., Error: The request was denied., Error: The request was denied. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (navigator.locks) { navigator.locks.request(key, lock => new Promise((f,r) => {})); let queryResult = await navigator.locks.query(); return queryResult.held[0].clientId; } else { throw new Error("Unsupported"); } } read: async () => { if (navigator.locks) { let queryResult = await navigator.locks.query(); return queryResult.held[0].name; } } result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: Error: The request was denied., Error: The request was denied., Error: The request was denied., Error: The request was denied. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
prefetch cacheA 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.
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: 1, 1, 1, 1 result, different first party: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
ServiceWorkerThe ServiceWorker API allows websites to run code in the background and store content in the browser for offline use. If a ServiceWorker can be accessed from multiple websites, it can be abused to track users across sites.
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> result, different first party: Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> result, different first party: Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined result, different first party: Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined result, different first party: Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined result, different first party: Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> result, different first party: Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: , , , result, different first party: , , , unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined result, different first party: Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined, Error: navigator.serviceWorker is undefined unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> result, different first party: Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> , <html> <head><title>404 Not Found</title></head> <body> <center><h1>404 Not Found</h1></center> <hr><center>nginx/1.18.0 (Ubuntu)</center> </body> </html> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> <!-- a padding to disable MSIE and Chrome friendly error page --> result, different first party: Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker., Error: Failed to register a ServiceWorker for scope ('https://test-pages.privacytests2.org/') with script ('https://test-pages.privacytests2.org/serviceWorker.js'): The user denied permission to use Service Worker. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
SharedWorkerThe 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.
  write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: Error: no SharedWorker message received, Error: no SharedWorker message received, Error: no SharedWorker message received, Error: no SharedWorker message received unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: Error: no SharedWorker message received, Error: no SharedWorker message received, Error: no SharedWorker message received, Error: no SharedWorker message received unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9, 2c6f0997-321a-4990-98e3-9bed415fdfab, a0f5c861-68a9-4067-912e-e3ac29777cfe, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: 1627bda0-b530-4117-8513-ed73801416d1, 968ea873-db17-4bf2-be9d-341c797feae5, 4156389a-5349-4c89-8b67-8f62b9932e06, 418fa667-dc9d-41db-807c-d08a0ae12221 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: b2e80bd9-c5cc-4808-b316-200e35e0a990, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3, 46b41978-e872-4efc-aa6a-4087cd8587d8 result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: Error: no SharedWorker message received, Error: no SharedWorker message received, Error: no SharedWorker message received, Error: no SharedWorker message received unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: 0e46c989-a36b-4473-b145-4d119e50d1b3, f67c8512-8836-4bb8-aa5a-29e094c3eca8, 3a3b164e-50cd-4baf-b2e8-e8375f83b300, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469 result, different first party: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: Error: no SharedWorker message received, Error: no SharedWorker message received, Error: no SharedWorker message received, Error: no SharedWorker message received unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); // console.log("worker", worker); const messagePromise = new Promise((resolve) => { worker.port.onmessage = (e) => resolve(e.data); }); worker.port.postMessage(secret); await messagePromise; } catch (e) { throw new Error("Unsupported"); } } read: async () => { let worker = new SharedWorker("supercookies_sharedworker.js"); worker.port.start(); const messagePromise = new Promise((resolve, reject) => { worker.port.onmessage = (e) => resolve(e.data); setTimeout(() => reject(new Error("no SharedWorker message received")), 200); }); worker.port.postMessage("request"); const message = await messagePromise; if (message === "none") { throw new Error("Unsupported"); } return message; } result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: Error: no SharedWorker message received, Error: no SharedWorker message received, Error: no SharedWorker message received, Error: no SharedWorker message received unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
TLS Session IDThe 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.
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: 8f9f0dd573045071a73f7cde89ea79cc67c2031b91ddb763e10a21d5d0a37cc1, 8035fca9c6be3a1446fd1b8c1d15287822698e14c4046340ed136b6a636c2f1d, ac15f1978295cd38fd551161f46a4877ef1bd397843d44569f7626e215ec4f21, 88b86605ef232610eb9d1bd5e93a4a80bb8a71590cac1291259a61e509dc4a12 result, different first party: d4bc328bab4c29877addf155e91286688564ddfdbe37e169c00a82496bdc6aea, d06fddc9b35f126ab2cd6c420a50dab48bebe3552111823bd5637afcb7278bfd, 6fd55fe01695de93124778d6059753f08404d760c7c91013ef64cefff5a48b5e, 83a5315418a159b54ae6b6c46d8d064602f9b45b090802440fb7f25ee137c3f6 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: 17299a0b28184e4339ad266042e26691e92e61810a6d11ceb10bf11c78bd52bd, a985cd68a38e90120fb7915d201ed0d6e81f1ab895616ed57e538bcaeb344b1c, e841283ab4ea56b7bca1d8aad3859d107be78c91bd3567a90f101f0969d3fa2a, b90a3c666068a6a35e3342a15bc524f1512a8474676019285d155e6878c7ba70 result, different first party: 85dd16e46a2f3f1bdb6d65a289f76c3aa767e1a38545142d50badda67f045cf5, 28d9bfce054eaf9aaf662a2f64dee5fed10a15202fa37570b8bf64c16aed5c56, 72918a43f8b94b53093a9d674e21dc0245ea4bd242fa505fdeba6e594891891d, 9596222d673ba89e9256d233e217ea3c85786813afccda7aab972f736f6e6c20 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: 2b98c89d2ae7a3d64aa8f37ad9a0714a5838d4bda550d18be9a6e2ccd6dab608, 36ce9156fe2bb2b4f6faffe65e39c9eca2276e47b7590040c47e33ea48677404, 3890a22c110c32fb319d1759cffd859d1af0e06192ffb682007b6ed3c9509f10, bee1160bf4d8981587752e7fa67a434ba9d9fd09140a3b2dcdca36c6b57b3e4e result, different first party: 003ab06b852a705d7fac7f0500af9c9cc5acd94513e9b59ea849a2a234bd2787, f753c9822bd267ccb6bce09b63b7d963686e88611aeeec0daa9191bca467f0fa, 5a30afdefc7f8c59f593ac5407790916b5ebd331c5e0cb97561b269eedc7a866, 45c75117e6760ba766a8f1d0d5fbf183a659811e0469770560fa138168dd50bf unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: 759a5104a569fa1075c41419982e77d4b3ee452e01b50531a1757c85c7b8686c, 62b6b1aa75105aa6f5cd6a47d7436f1ef3263223873d62dea1c2b6614cd8a120, 704d8b6f591716cbeeed28839fd6a09d8512574527d6d71a903339344ce6d75e, 226d23bc3fec75898cb7654d1a178dd4a3b769354342c1471e549ee79750a1ac result, different first party: 423833870e1b9f576ac412152ae4d94b8e9d0ccd075ce527209413c1786136c8, 55109bceb8b7513073d91eaa7c6179834d243e707edff3098da68312619238dc, e99cdf4dd55ada5ed770051fc5a39cfc87896c09b10de48f3eeca1688dcc0cc3, ec7b04dbb068e8319a0d7607592e4b8ec4ea6dc145d430bf543e99056ea8b9ae unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: 051f435700e557fbdc875f058b0ae3ca1068da020d338ce59d8f8fbad72e172b, 3d514da033e53e6451cd3f7864e64da7e87b9fbffc41ca7710acbd4d578fc541, 658813172d1d5c8f9adc7f0cb49fdd1edc1d124b0acabc975e65724fd6db56e8, 4d1fb7ab7567dd14e131fa3d9c8bb7a468605c77d8c8268a94868062cd331941 result, different first party: 4bcd473b8eceb94a69708049460e14c3e9cbaee15f7153fe5d786d26e24634f2, 2ae5c00dbdfbfd193e3142ae6a9b19015fbde52bcacf9d981a989124bb31a515, 37c5c78af7844e4f57a3458ef78bba3f1bee68c06ff6fa344994d80a1e223d93, d95793d4c0e3d12235b86a37b33a95577c0fdea94aba7b497eba352e7d8c7fab unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: f300e89c305845c037e512d0e7dad9b36e443f5563c41f464ce4fe9509790e1a, 18f4ef3ce9584475cd82c7f071f8fa49f4702466edc00436a4cd7177845b18b2, 4fd058106831787f165832ffeb3e145ab2a7152a8daefdbe2abe6a6dbed74a46, fc41fbf2bda8225276ed7efd15be13b3c0c5bee865c1085ab03eb81fc8c86bc4 result, different first party: bf31081c35517e57dd142f7992c214d5d1224d68dbbdd6a3314bfd647d576a21, 6ddf7c7357e969b5f0811901cd48f55130af53b1804c233430e08d5c436af1df, b5247b6e62175547e7b485b01f5a586d1debfb30117daa94755380da6b1bcccf, 202a2e11eb9bbda4ea9be7eed0e94380073a737f24d4fc6cdc4476d131fa50d5 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: 886d4ca3dfba2535b3937345abe331f32a685500a7c3ee411ec7319ecd9ce412, d8fd7a9ff1aaa184043eaa57d74b0bb86077389297ec7cd6023525f86c6035d2, af9c9425761d135790ad12c359b175e339db04ff59309b9fe9bfee3f0980c819, 78faf64454e9e3b4c7e5a716868259988717e8cfbfd0eab0d4ef7ebf0fdfffb7 result, different first party: 44e41fb72942998563c3c45513cbcca5f20d83f9d080d83369eba0774cea7233, d18c5166e13f46e2618d871c7d0d16e5bddbd09f1b6a4c50aa1e5a45f2bcf062, 6eff015e0a4e6b81f04d9daefedb01d69218ad339390c9007427228bc5939d84, 63ed9d2b8bcd498ff9f4ac789e4e0a645197945ad3cb9e538e9176383e9d6691 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: 784a9a0d199e41d693a4d8498e657a76a03300c132ec7898886b06556ff96afe, 1c28021f1ce210f783d635c8c1872754b995b40dc4eecf3f6717e17cef23cd84, 30662066e65367c51f4a13469a3069257c280a3e1229539e24ff2627c6a7c00a, ca833ab340d91fedb8412fd0db10662dbfc52809b97926685e87b2128ad926f1 result, different first party: 12f055a0d2dbde1ae9dcbb079912ee9b4d060b05a194ec14975887b607ad6e37, 2f545ccbce302dc604baf648a54a2cb0915e65257377986b5e3a8f0c1a1e4e42, c85d95d51d0bd4a074d208a7256660e3a5c7acc37e969e543146d57c6fbe8fd5, ec29083b10dbf3e049c6619ba599051eef1f622c7a97fcbe3519c6fbe707dc57 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: eb777e0d048e9b07b6234cace80a7e1fa0de2cb2de635f236951832c1d13e268, b0cac8d6631924e65208b1b5a7230da2c9439efbf70cd9ac6bbadb2b97688e2b, 5654a2d86b5ef26b84d7dfdc2f2c6413711e473d0988c3553889158050ba3fcb, a9f3ba6cf901ac13958cdb03263a270e8fd786050628a4cbb36281b946eba025 result, different first party: 9db6ac1cec60830a3bbdd3febcee2e248aba06ff76c6af5ebd5d138e9bc9b6cd, 046a17e1801d15d8d45dc7d8b9edf61a4b94ad6d86a1d3ab8c52101f0c9a6da3, 0e3d4b9462953edfbf89241e111648ed440fef9af5378fef67a523f2b897c0c1, 675158216520e51a2e1e1b76b6084d3ed13dce521418457ccb591c9bd15ec678 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: 2a83ce6487dd4bc9eae806d9127b6f258ddfb6fa17e9eaf9a268951337031e63, 9ff852ed0291f3a2a9c8865b6f35cb9ae02ff8094f9ea7d7031c5920adb66b2e, a2070117b0d3142c3d47c4369932ced3a8c87e02100cff68445eb149ba51848c, 5be63714d822c85daba48c084b7530d033818798eba112ed5d0b21fca27a33ab result, different first party: 159aebcc7ba70616ecf7ee82d1c98860e3fa7f820861c7bfb1707924bb025d85, 10c36902ec5bb8bd735d50feff2bc5af3f262df5ccc5b1980c2fd946fb5ea00f, 6efcb7ab3598466458fd88c880b9a45b4ece057e1a1dc8d8d9e0132c2b9becc2, f91b066e4c6ff1dac3327cbf59844c8d840541fa8211bf35061aa251c63eecdb unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } read: async () => { let results = await fetch("https://tls.privacytests2.org:8900/"); return (await results.json()).sessionId; } result, same first party: 05228f588668df3ec824c5dd7210a7278cf40e9319c488552fa8e2c13fc53168, 47ec294b09181ae19367e80c51c338bd758dbc174dee588b280912c97f5907ed, 558550d05eecd7f8e77bf7305df5a482eee2dde6f149b643ae5b855eb44d580c, 385cc275a6f4522ce10734a4ab6c971fcc982f983af07adf5f9e1952a3976372 result, different first party: bd1576a44b87722f939a9eb6b83c08f5cc30772563607ce61f0a5f55a02d7e42, 067c9aab6956f01685b3654753aa8a55286c08aaefec02095f25e12cd7b9a9de, e28df40f3497bb27f30f67a8e68a487862ea911950e843e66e59d55634d34788, 0680e7dbaa98bc592e8ce3b9c3d31b6711f745e7229ebca4f344a17bf35e773d unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
Web SQL DatabaseThe Web SQL Database is a deprecated web API for storing data in an SQL database.
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different first party: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different first party: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different first party: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated result, different first party: Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different first party: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: false, false, false, false passed: undefined test failed: true, true, true, true
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
XMLHttpRequest cacheSimilar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 2, 2, 2, 2 result, different first party: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1 result, different first party: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
Navigation tests Which 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.referrerThe 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.
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
sessionStorageThe 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.
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: d91ebb72-df9c-4f41-95b5-60e241890671, 3a97209b-1788-4386-a100-c1f080f208ed, 5220841f-fa5d-41c4-8328-9c0b0a79663c, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 01e86091-e4d2-426d-8107-14b24f9d3c32, 53f6f750-08ee-4fff-9e9f-9727a6546c57, 67c74d28-b18c-480d-82a4-026d6c7113dd, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: 8848d48e-6d6d-4e5c-a2f3-206e1586a312, 60422fe9-a24b-4999-b491-7ab178c79ad3, 5fc445e2-97c0-406e-b955-2cf486b66d02, f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 9915b131-e392-4f54-b0b0-10a779442cd9, 2c6f0997-321a-4990-98e3-9bed415fdfab, a0f5c861-68a9-4067-912e-e3ac29777cfe, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 1627bda0-b530-4117-8513-ed73801416d1, 968ea873-db17-4bf2-be9d-341c797feae5, 4156389a-5349-4c89-8b67-8f62b9932e06, 418fa667-dc9d-41db-807c-d08a0ae12221 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: b2e80bd9-c5cc-4808-b316-200e35e0a990, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3, 46b41978-e872-4efc-aa6a-4087cd8587d8 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, 486753ac-5ee1-4845-914e-b4d447cdd0d9, 7cd6bf02-0547-450d-8c9c-6ce3a6470342, 919dfb09-a069-466e-a150-77755c21db77 result, different first party: Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 4ed495a7-f48e-4f77-b708-94103a402c59, 2e179ccf-38d7-4737-b3e8-10e322d5eaa1, e1880837-3bc0-49d5-9e52-dc63f6c73481, 7e77c95d-797e-45d7-b295-d6a967650db8 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 0e46c989-a36b-4473-b145-4d119e50d1b3, f67c8512-8836-4bb8-aa5a-29e094c3eca8, 3a3b164e-50cd-4baf-b2e8-e8375f83b300, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 59caff2f-a419-4ac4-b969-e861161dfbf7, 788cdb07-a775-4451-a85f-b542851f8a4c, 39ca5981-befe-4339-a896-569a4c66ad80, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, 913a2832-170f-4e90-854d-7280946144ab, c28a7953-008f-4fa5-8e15-12750255bf16, 00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'sessionStorage' property from 'Window': Access is denied for this document. unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
window.nameThe 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.
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_d91ebb72-df9c-4f41-95b5-60e241890671, name_3a97209b-1788-4386-a100-c1f080f208ed, name_5220841f-fa5d-41c4-8328-9c0b0a79663c, name_ea3ce35d-be5c-40cf-b8e0-ef191a4753c7 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_01e86091-e4d2-426d-8107-14b24f9d3c32, name_53f6f750-08ee-4fff-9e9f-9727a6546c57, name_67c74d28-b18c-480d-82a4-026d6c7113dd, name_2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 result, different first party: name_01e86091-e4d2-426d-8107-14b24f9d3c32, name_53f6f750-08ee-4fff-9e9f-9727a6546c57, name_67c74d28-b18c-480d-82a4-026d6c7113dd, name_2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_8848d48e-6d6d-4e5c-a2f3-206e1586a312, name_60422fe9-a24b-4999-b491-7ab178c79ad3, name_5fc445e2-97c0-406e-b955-2cf486b66d02, name_f55fb1ed-8d31-46a3-a27f-4c03925b604e result, different first party: name_8848d48e-6d6d-4e5c-a2f3-206e1586a312, name_60422fe9-a24b-4999-b491-7ab178c79ad3, name_5fc445e2-97c0-406e-b955-2cf486b66d02, name_f55fb1ed-8d31-46a3-a27f-4c03925b604e unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_9915b131-e392-4f54-b0b0-10a779442cd9, name_2c6f0997-321a-4990-98e3-9bed415fdfab, name_a0f5c861-68a9-4067-912e-e3ac29777cfe, name_07c63936-e6c6-4ad3-91e0-e0bcd7a67186 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_1627bda0-b530-4117-8513-ed73801416d1, name_968ea873-db17-4bf2-be9d-341c797feae5, name_4156389a-5349-4c89-8b67-8f62b9932e06, name_418fa667-dc9d-41db-807c-d08a0ae12221 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_b2e80bd9-c5cc-4808-b316-200e35e0a990, name_996b0b8c-6353-4213-b5cc-14ca48e9e5c5, name_8d81517f-ddcc-4b76-95d5-f08ab58a5aa3, name_46b41978-e872-4efc-aa6a-4087cd8587d8 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, name_486753ac-5ee1-4845-914e-b4d447cdd0d9, name_7cd6bf02-0547-450d-8c9c-6ce3a6470342, name_919dfb09-a069-466e-a150-77755c21db77 result, different first party: name_0c85c8dc-0ed1-4868-9abb-1b1b1adcb990, name_486753ac-5ee1-4845-914e-b4d447cdd0d9, name_7cd6bf02-0547-450d-8c9c-6ce3a6470342, name_919dfb09-a069-466e-a150-77755c21db77 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_4ed495a7-f48e-4f77-b708-94103a402c59, name_2e179ccf-38d7-4737-b3e8-10e322d5eaa1, name_e1880837-3bc0-49d5-9e52-dc63f6c73481, name_7e77c95d-797e-45d7-b295-d6a967650db8 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_0e46c989-a36b-4473-b145-4d119e50d1b3, name_f67c8512-8836-4bb8-aa5a-29e094c3eca8, name_3a3b164e-50cd-4baf-b2e8-e8375f83b300, name_4c1f1966-f9e9-4aec-b90b-9ec7eff63469 result, different first party: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_59caff2f-a419-4ac4-b969-e861161dfbf7, name_788cdb07-a775-4451-a85f-b542851f8a4c, name_39ca5981-befe-4339-a896-569a4c66ad80, name_a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 result, different first party: name_59caff2f-a419-4ac4-b969-e861161dfbf7, name_788cdb07-a775-4451-a85f-b542851f8a4c, name_39ca5981-befe-4339-a896-569a4c66ad80, name_a29461a4-0ca6-4c51-bc4d-fc9724ce55b4 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, name_913a2832-170f-4e90-854d-7280946144ab, name_c28a7953-008f-4fa5-8e15-12750255bf16, name_00124808-29a4-4b8b-9477-b17c1f0fcac4 result, different first party: name_ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2, name_913a2832-170f-4e90-854d-7280946144ab, name_c28a7953-008f-4fa5-8e15-12750255bf16, name_00124808-29a4-4b8b-9477-b17c1f0fcac4 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
HTTPS tests Which browsers use encrypted network connections whenever possible?
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 websiteChecks 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.
  passed: false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: true,true,true,true result: Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded
  passed: true,true,true,true result: Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded
  passed: false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: true,true,true,true result: Insecure website never loaded,Insecure website never loaded,Insecure website never loaded,Insecure website never loaded
  passed: false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
Upgradable addressChecks to see if an insecure address entered into the browser's address bar is upgraded to HTTPS whenever possible.
  upgraded: true,true,true,true passed: true,true,true,true
  upgraded: false,false,true,true passed: false,false,true,true
  upgraded: false,false,false,false passed: false,false,false,false
  upgraded: true,true,true,true passed: true,true,true,true
  upgraded: true,true,true,true passed: true,true,true,true
  upgraded: true,true,true,true passed: true,true,true,true
  upgraded: false,false,false,false passed: false,false,false,false
  upgraded: false,false,false,false passed: false,false,false,false
  upgraded: true,true,true,true passed: true,true,true,true
  upgraded: false,false,false,false passed: false,false,false,false
  upgraded: false,false,false,false passed: false,false,false,false
Upgradable hyperlinkChecks to see if the user has clicked on a hyperlink to an insecure address, if the browser upgrades that address to HTTPS whenever possible.
  upgraded: true,true,true,true passed: true,true,true,true
  upgraded: false,false,true,true passed: false,false,true,true
  upgraded: false,false,false,false passed: false,false,false,false
  upgraded: true,true,true,true passed: true,true,true,true
  upgraded: true,true,true,true passed: true,true,true,true
  upgraded: true,true,true,true passed: true,true,true,true
  upgraded: false,false,false,false passed: false,false,false,false
  upgraded: false,false,false,false passed: false,false,false,false
  upgraded: true,true,true,true passed: true,true,true,true
  upgraded: false,false,false,false passed: false,false,false,false
  upgraded: false,false,false,false passed: false,false,false,false
Upgradable imageChecks to see if the browser attempts to upgrade an insecure address for an image to HTTPS whenever possible.
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: false,false,false,false result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: false,false,false,false result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
Upgradable scriptChecks to see if the browser attempts to upgrade an insecure address for an script to HTTPS whenever possible.
  passed: true,true,true,true result: blocked,blocked,blocked,blocked
  passed: true,true,true,true result: blocked,blocked,blocked,blocked
  passed: true,true,true,true result: blocked,blocked,blocked,blocked
  passed: true,true,true,true result: blocked,blocked,blocked,blocked
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: true,true,true,true result: blocked,blocked,blocked,blocked
  passed: true,true,true,true result: blocked,blocked,blocked,blocked
  passed: true,true,true,true result: upgraded,upgraded,upgraded,upgraded
  passed: true,true,true,true result: blocked,blocked,blocked,blocked
  passed: true,true,true,true result: blocked,blocked,blocked,blocked
Misc tests Which browsers provide additional assorted privacy protections?
This category includes tests for the presence of miscellaneous privacy features
GPC enabled first-partyThe 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.
  header value: 1 passed: true,true,true,true
  header value: undefined passed: false,false,false,false
  header value: undefined passed: false,false,false,false
  header value: undefined passed: false,false,false,false
  header value: undefined passed: false,false,false,false
  header value: undefined passed: false,false,false,false
  header value: undefined passed: false,false,false,false
  header value: undefined passed: false,false,false,false
  header value: undefined passed: false,false,false,false
  header value: undefined passed: false,false,false,false
  header value: undefined passed: false,false,false,false
GPC enabled third-partyThe 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.
  sec-gpc: 1 passed: true,true,true,true
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
IP address leakIP addresses can be used to uniquely identify a large percentage of users. A proxy, VPN, or Tor can mask a user's IP address.
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: false,false,false,false
  passed: true,true,true,true
  passed: false,false,false,false
  passed: false,false,false,false
Stream isolationBrowsers that use Tor can use a different Tor circuit per top-level website.
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false
  write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: false,false,false,false readSameFirstParty: 2001:678:d64:564d::70e,185.220.101.131,38.97.116.244,185.220.101.131 readDifferentFirstParty: 2a0b:f4c2:2::39,Error: Unsupported,2a0b:f4c2:2::32,2a0b:f4c2:2::36 passed: true,true,true,true testFailed: false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false
Tor enabledThe 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.
  IsTorExit: false,false,false,false passed: false,false,false,false
  IsTorExit: false,false,false,false passed: false,false,false,false
  IsTorExit: false,false,false,false passed: false,false,false,false
  IsTorExit: false,false,false,false passed: false,false,false,false
  IsTorExit: false,false,false,false passed: false,false,false,false
  IsTorExit: false,false,false,false passed: false,false,false,false
  IsTorExit: false,false,false,false passed: false,false,false,false
  IsTorExit: false,false,false,false passed: false,false,false,false
  IsTorExit: true,true,true,true passed: true,true,true,true
  IsTorExit: false,false,false,false passed: false,false,false,false
  IsTorExit: false,false,false,false passed: false,false,false,false
Fingerprinting resistance tests Which browsers hide what's unique about your device?
Fingerprinting is a technique trackers use to uniquely identify you as you browse the web. A fingerprinting script will measure several characteristics of your browser and, combining this data, will build a fingerprint that may uniquely identify you among web users. Browsers can introduce countermeasures, such as minimizing the distinguishing information disclosed by certain web APIs so your browser is harder to pick out from the crowd (so-called 'fingerprinting resistance').`,
Media query screen heightHeight of the user's screen in pixels.
  expression: undefined desired expression: undefined actual value: 1302,1300,1299,1304 desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 928,928,928,928 desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: 1000,1000,1000,1000 desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 1000,1000,1000,1000 desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
Media query screen widthWidth of the user's screen in pixels.
  expression: undefined desired expression: undefined actual value: 1201,1204,1206,1203 desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 1600,1600,1600,1600 desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: 1000,1000,1000,1000 desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 1000,1000,1000,1000 desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
outerHeightHeight of the browser window in pixels, including browser chrome.
  expression: outerHeight desired expression: undefined actual value: 1302,1300,1299,1304 desired value: undefined passed: true,true,true,true
  expression: outerHeight desired expression: undefined actual value: 1371,1371,1371,1371 desired value: undefined passed: false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 1371,1371,1371,1371 desired value: undefined passed: false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 1040,1040,1040,1040 desired value: undefined passed: false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 928,928,928,928 desired value: undefined passed: true,true,true,true
  expression: outerHeight desired expression: undefined actual value: 1000,1000,1000,1000 desired value: undefined passed: true,true,true,true
  expression: outerHeight desired expression: undefined actual value: 1061,1061,1061,1061 desired value: undefined passed: false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 1415,1415,1415,1415 desired value: undefined passed: false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 1000,1000,1000,1000 desired value: undefined passed: true,true,true,true
  expression: outerHeight desired expression: undefined actual value: 1371,1371,1371,1371 desired value: undefined passed: false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 1371,1371,1371,1371 desired value: undefined passed: false,false,false,false
screen.heightHeight of the user's screen, in pixels.
  expression: screen.height desired expression: undefined actual value: 1302,1300,1299,1304 desired value: undefined passed: true,true,true,true
  expression: screen.height desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: screen.height desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: screen.height desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: screen.height desired expression: undefined actual value: 928,928,928,928 desired value: undefined passed: true,true,true,true
  expression: screen.height desired expression: undefined actual value: 1000,1000,1000,1000 desired value: undefined passed: true,true,true,true
  expression: screen.height desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: screen.height desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: screen.height desired expression: undefined actual value: 1000,1000,1000,1000 desired value: undefined passed: true,true,true,true
  expression: screen.height desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
  expression: screen.height desired expression: undefined actual value: 1440,1440,1440,1440 desired value: undefined passed: false,false,false,false
screen.widthWidth of the user's screen, in pixels.
  expression: screen.width desired expression: undefined actual value: 1201,1204,1206,1203 desired value: undefined passed: true,true,true,true
  expression: screen.width desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: screen.width desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: screen.width desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: screen.width desired expression: undefined actual value: 1600,1600,1600,1600 desired value: undefined passed: true,true,true,true
  expression: screen.width desired expression: undefined actual value: 1000,1000,1000,1000 desired value: undefined passed: true,true,true,true
  expression: screen.width desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: screen.width desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: screen.width desired expression: undefined actual value: 1000,1000,1000,1000 desired value: undefined passed: true,true,true,true
  expression: screen.width desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
  expression: screen.width desired expression: undefined actual value: 2560,2560,2560,2560 desired value: undefined passed: false,false,false,false
screenXPosition, in pixels, of the left edge of the browser window on screen.
  expression: screenX desired expression: undefined actual value: 1,7,7,1 desired value: undefined passed: true,true,true,true
  expression: screenX desired expression: undefined actual value: 22,22,22,22 desired value: undefined passed: false,false,false,false
  expression: screenX desired expression: undefined actual value: 22,22,22,22 desired value: undefined passed: false,false,false,false
  expression: screenX desired expression: undefined actual value: 4,4,4,4 desired value: undefined passed: true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0 desired value: undefined passed: true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0 desired value: undefined passed: true,true,true,true
  expression: screenX desired expression: undefined actual value: 320,320,320,320 desired value: undefined passed: false,false,false,false
  expression: screenX desired expression: undefined actual value: 592,592,592,592 desired value: undefined passed: false,false,false,false
  expression: screenX desired expression: undefined actual value: 0,0,0,0 desired value: undefined passed: true,true,true,true
  expression: screenX desired expression: undefined actual value: 22,22,22,22 desired value: undefined passed: false,false,false,false
  expression: screenX desired expression: undefined actual value: 22,22,22,22 desired value: undefined passed: false,false,false,false
screenYPosition, in pixels, of the top edge of the browser window on screen.
  expression: screenY desired expression: undefined actual value: 8,2,0,0 desired value: undefined passed: true,true,true,true
  expression: screenY desired expression: undefined actual value: 47,47,47,47 desired value: undefined passed: false,false,false,false
  expression: screenY desired expression: undefined actual value: 47,47,47,47 desired value: undefined passed: false,false,false,false
  expression: screenY desired expression: undefined actual value: 25,25,25,25 desired value: undefined passed: false,false,false,false
  expression: screenY desired expression: undefined actual value: 0,0,0,0 desired value: undefined passed: true,true,true,true
  expression: screenY desired expression: undefined actual value: 0,0,0,0 desired value: undefined passed: true,true,true,true
  expression: screenY desired expression: undefined actual value: 202,202,202,202 desired value: undefined passed: false,false,false,false
  expression: screenY desired expression: undefined actual value: 25,25,25,25 desired value: undefined passed: false,false,false,false
  expression: screenY desired expression: undefined actual value: 0,0,0,0 desired value: undefined passed: true,true,true,true
  expression: screenY desired expression: undefined actual value: 47,47,47,47 desired value: undefined passed: false,false,false,false
  expression: screenY desired expression: undefined actual value: 47,47,47,47 desired value: undefined passed: false,false,false,false
System font detectionWeb pages can detect the presence of a font installed on the user's system. The presence or absence of various fonts is commonly used to fingerprint users.
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: true,true,true,true
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: false,false,false,false
  expression: undefined desired expression: undefined actual value: undefined desired value: undefined passed: false,false,false,false
Tracking query parameter tests Which 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.)`
__hsfpHubSpot tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
__hsscHubSpot tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
__hstcHubSpot tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
__sDrip.com email address tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
_hsencHubSpot tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
_openstatYandex tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
dclidDoubleClick Click ID (Google)
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
fbclidFacebook Click Identifier
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
gclidGoogle Click Identifier
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
hsCtaTrackingHubSpot tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
mc_eidMailchimp Email ID (email recipient's address)
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
mkt_tokAdobe Marketo tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
ml_subscriberMailerLite email tracking
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
ml_subscriber_hashMailerLite email tracking
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
msclkidMicrosoft Click ID
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
oly_anon_idOmeda marketing 'anonymous' customer id
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
oly_enc_idOmeda marketing 'known' customer id
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
rb_clickidUnknown high-entropy tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
s_cidAdobe Site Catalyst tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
vero_convVero tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
vero_idVero tracking parameter
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
wickedidWicked Reports e-commerce tracking
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
yclidYandex Click ID
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  passed: true,true,true,true
  passed: true,true,true,true
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
  value: 6472679007464266 passed: false,false,false,false
Tracker content blocking tests Which 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.`
AdobeTests whether the browser blocks the page from loading the tracker at https://munchkin.marketo.net/munchkin.js
  url: https://munchkin.marketo.net/munchkin.js passed: true,true,true,true
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: true,true,true,true
  url: https://munchkin.marketo.net/munchkin.js passed: true,true,true,true
  url: https://munchkin.marketo.net/munchkin.js passed: true,true,true,true
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false
Adobe Audience ManagerTests whether the browser blocks the page from loading the tracker at https://dpm.demdex.net/ibs
  url: https://dpm.demdex.net/ibs passed: true,true,true,true
  url: https://dpm.demdex.net/ibs passed: false,false,false,false
  url: https://dpm.demdex.net/ibs passed: false,false,false,false
  url: https://dpm.demdex.net/ibs passed: true,true,true,true
  url: https://dpm.demdex.net/ibs passed: true,true,true,true
  url: https://dpm.demdex.net/ibs passed: true,true,true,true
  url: https://dpm.demdex.net/ibs passed: false,false,false,false
  url: https://dpm.demdex.net/ibs passed: false,false,false,false
  url: https://dpm.demdex.net/ibs passed: false,false,false,false
  url: https://dpm.demdex.net/ibs passed: false,false,false,false
  url: https://dpm.demdex.net/ibs passed: false,false,false,false
Amazon adsystemTests whether the browser blocks the page from loading the tracker at https://s.amazon-adsystem.com/dcm
  url: https://s.amazon-adsystem.com/dcm passed: true,true,true,true
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: true,true,true,true
  url: https://s.amazon-adsystem.com/dcm passed: true,true,true,true
  url: https://s.amazon-adsystem.com/dcm passed: true,true,true,true
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false
AppNexusTests whether the browser blocks the page from loading the tracker at https://ib.adnxs.com/px?id=178248&t=1
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: true,true,true,true
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: true,true,true,true
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: true,true,true,true
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: true,true,true,true
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false
Bing AdsTests whether the browser blocks the page from loading the tracker at https://bat.bing.com/bat.js
  url: https://bat.bing.com/bat.js passed: true,true,true,true
  url: https://bat.bing.com/bat.js passed: false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false
  url: https://bat.bing.com/bat.js passed: true,true,true,true
  url: https://bat.bing.com/bat.js passed: true,true,true,true
  url: https://bat.bing.com/bat.js passed: false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false
ChartbeatTests whether the browser blocks the page from loading the tracker at https://static.chartbeat.com/js/chartbeat.js
  url: https://static.chartbeat.com/js/chartbeat.js passed: true,true,true,true
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: true,true,true,true
  url: https://static.chartbeat.com/js/chartbeat.js passed: true,true,true,true
  url: https://static.chartbeat.com/js/chartbeat.js passed: true,true,true,true
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false
CriteoTests whether the browser blocks the page from loading the tracker at https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: true,true,true,true
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: true,true,true,true
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: true,true,true,true
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: true,true,true,true
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: 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
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: true,true,true,true
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: true,true,true,true
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: true,true,true,true
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: true,true,true,true
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false
Facebook trackingTests whether the browser blocks the page from loading the tracker at https://connect.facebook.net/en_US/fbevents.js
  url: https://connect.facebook.net/en_US/fbevents.js passed: true,true,true,true
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: true,true,true,true
  url: https://connect.facebook.net/en_US/fbevents.js passed: true,true,true,true
  url: https://connect.facebook.net/en_US/fbevents.js passed: true,true,true,true
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: 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/
  url: https://www.google.com/pagead/1p-user-list/ passed: true,true,true,true
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: true,true,true,true
  url: https://www.google.com/pagead/1p-user-list/ passed: true,true,true,true
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false
Google AnalyticsTests whether the browser blocks the page from loading the tracker at https://google-analytics.com/urchin.js
  url: https://google-analytics.com/urchin.js passed: true,true,true,true
  url: https://google-analytics.com/urchin.js passed: false,false,false,false
  url: https://google-analytics.com/urchin.js passed: false,false,false,false
  url: https://google-analytics.com/urchin.js passed: true,true,true,true
  url: https://google-analytics.com/urchin.js passed: true,true,true,true
  url: https://google-analytics.com/urchin.js passed: true,true,true,true
  url: https://google-analytics.com/urchin.js passed: false,false,false,false
  url: https://google-analytics.com/urchin.js passed: false,false,false,false
  url: https://google-analytics.com/urchin.js passed: false,false,false,false
  url: https://google-analytics.com/urchin.js passed: false,false,false,false
  url: https://google-analytics.com/urchin.js passed: false,false,false,false
Google Tag ManagerTests whether the browser blocks the page from loading the tracker at https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: true,true,true,true
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: true,true,true,true
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: true,true,true,true
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false
Index ExchangeTests 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
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: true,true,true,true
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,false,false,false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,false,false,false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: true,true,true,true
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: true,true,true,true
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: true,true,true,true
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,false,false,false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,false,false,false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,false,false,false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,false,false,false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,false,false,false
New RelicTests whether the browser blocks the page from loading the tracker at https://js-agent.newrelic.com/nr-1212.min.js
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: true,true,true,true
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: true,true,true,true
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: true,true,true,true
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: true,true,true,true
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false
QuantcastTests whether the browser blocks the page from loading the tracker at https://pixel.quantserve.com/pixel
  url: https://pixel.quantserve.com/pixel passed: true,true,true,true
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: true,true,true,true
  url: https://pixel.quantserve.com/pixel passed: true,true,true,true
  url: https://pixel.quantserve.com/pixel passed: true,true,true,true
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false
Scorecard Research BeaconTests whether the browser blocks the page from loading the tracker at https://sb.scorecardresearch.com/internal-c2/default/cs.js
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: true,true,true,true
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: true,true,true,true
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: true,true,true,true
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: true,true,true,true
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false
TaboolaTests whether the browser blocks the page from loading the tracker at https://trc.taboola.com/futureplc-tomsguide/trc/3/json
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: true,true,true,true
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: true,true,true,true
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: true,true,true,true
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: true,true,true,true
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false
Twitter pixelTests whether the browser blocks the page from loading the tracker at https://t.co/i/adsct
  url: https://t.co/i/adsct passed: true,true,true,true
  url: https://t.co/i/adsct passed: false,false,false,false
  url: https://t.co/i/adsct passed: false,false,false,false
  url: https://t.co/i/adsct passed: true,true,true,true
  url: https://t.co/i/adsct passed: true,true,true,true
  url: https://t.co/i/adsct passed: true,true,true,true
  url: https://t.co/i/adsct passed: false,false,false,false
  url: https://t.co/i/adsct passed: false,false,false,false
  url: https://t.co/i/adsct passed: false,false,false,false
  url: https://t.co/i/adsct passed: false,false,false,false
  url: https://t.co/i/adsct passed: false,false,false,false
Yandex AdsTests whether the browser blocks the page from loading the tracker at https://yandex.ru/ads/system/header-bidding.js
  url: https://yandex.ru/ads/system/header-bidding.js passed: true,true,true,true
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: true,true,true,true
  url: https://yandex.ru/ads/system/header-bidding.js passed: true,true,true,true
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false
Tracking cookie protection tests Which browsers block important known tracking cookies?
A large fraction of web pages on the web have hidden third-party trackers that read and write cookies in your browser. These cookies can be used to track your browsing across websites. This section checks to see if a browser stops cross-site tracking by cookies from 20 of the largest trackers listed by https://whotracks.me.`,
AdobeTests whether the browser stops cookies from munchkin.marketo.net from tracking users across websites.
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://munchkin.marketo.net/munchkin.js cookieFound: false,false,false,false
Adobe Audience ManagerTests whether the browser stops cookies from dpm.demdex.net from tracking users across websites.
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dpm.demdex.net/ibs cookieFound: false,false,false,false
Amazon adsystemTests whether the browser stops cookies from s.amazon-adsystem.com from tracking users across websites.
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
  passed: true,true,true,true url: https://s.amazon-adsystem.com/dcm cookieFound: false,false,false,false
AppNexusTests whether the browser stops cookies from ib.adnxs.com from tracking users across websites.
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://ib.adnxs.com/px?id=178248&t=1 cookieFound: false,false,false,false
Bing AdsTests whether the browser stops cookies from bat.bing.com from tracking users across websites.
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://bat.bing.com/bat.js cookieFound: false,false,false,false
ChartbeatTests whether the browser stops cookies from static.chartbeat.com from tracking users across websites.
  passed: true,true,true,true url: https://static.chartbeat.com/js/chartbeat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://static.chartbeat.com/js/chartbeat.js cookieFound: false,false,false,false
  passed: false,false,false,false url: https://static.chartbeat.com/js/chartbeat.js cookieFound: true,true,true,true
  passed: true,true,true,true url: https://static.chartbeat.com/js/chartbeat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://static.chartbeat.com/js/chartbeat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://static.chartbeat.com/js/chartbeat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://static.chartbeat.com/js/chartbeat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://static.chartbeat.com/js/chartbeat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://static.chartbeat.com/js/chartbeat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://static.chartbeat.com/js/chartbeat.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://static.chartbeat.com/js/chartbeat.js cookieFound: false,false,false,false
CriteoTests whether the browser stops cookies from dis.criteo.com from tracking users across websites.
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx cookieFound: false,false,false,false
DoubleClick (Google)Tests whether the browser stops cookies from securepubads.g.doubleclick.net from tracking users across websites.
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://securepubads.g.doubleclick.net/static/glade.js cookieFound: false,false,false,false
Facebook trackingTests whether the browser stops cookies from connect.facebook.net from tracking users across websites.
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://connect.facebook.net/en_US/fbevents.js cookieFound: false,false,false,false
Google (third-party ad pixel)Tests whether the browser stops cookies from www.google.com from tracking users across websites.
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.google.com/pagead/1p-user-list/ cookieFound: false,false,false,false
Google AnalyticsTests whether the browser stops cookies from google-analytics.com from tracking users across websites.
  passed: true,true,true,true url: https://google-analytics.com/urchin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://google-analytics.com/urchin.js cookieFound: false,false,false,false
  passed: false,false,false,false url: https://google-analytics.com/urchin.js cookieFound: true,true,true,true
  passed: true,true,true,true url: https://google-analytics.com/urchin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://google-analytics.com/urchin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://google-analytics.com/urchin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://google-analytics.com/urchin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://google-analytics.com/urchin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://google-analytics.com/urchin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://google-analytics.com/urchin.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://google-analytics.com/urchin.js cookieFound: false,false,false,false
Google Tag ManagerTests whether the browser stops cookies from www.googletagmanager.com from tracking users across websites.
  passed: true,true,true,true url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: false,false,false,false
  passed: false,false,false,false url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: true,true,true,true
  passed: true,true,true,true url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: false,false,false,false
  passed: true,true,true,true url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL cookieFound: false,false,false,false
Index ExchangeTests whether the browser stops cookies from dsum-sec.casalemedia.com from tracking users across websites.
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
  passed: true,true,true,true url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 cookieFound: false,false,false,false
New RelicTests whether the browser stops cookies from js-agent.newrelic.com from tracking users across websites.
  passed: true,true,true,true url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: false,false,false,false
  passed: false,false,false,false url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: true,true,true,true
  passed: true,true,true,true url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://js-agent.newrelic.com/nr-1212.min.js cookieFound: false,false,false,false
QuantcastTests whether the browser stops cookies from pixel.quantserve.com from tracking users across websites.
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
  passed: true,true,true,true url: https://pixel.quantserve.com/pixel cookieFound: false,false,false,false
Scorecard Research BeaconTests whether the browser stops cookies from sb.scorecardresearch.com from tracking users across websites.
  passed: true,true,true,true url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: false,false,false,false
  passed: false,false,false,false url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: true,true,true,true
  passed: true,true,true,true url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://sb.scorecardresearch.com/internal-c2/default/cs.js cookieFound: false,false,false,false
TaboolaTests whether the browser stops cookies from trc.taboola.com from tracking users across websites.
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
  passed: true,true,true,true url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json cookieFound: false,false,false,false
Twitter pixelTests whether the browser stops cookies from t.co from tracking users across websites.
  passed: true,true,true,true url: https://t.co/i/adsct cookieFound: false,false,false,false
  passed: true,true,true,true url: https://t.co/i/adsct cookieFound: false,false,false,false
  passed: false,false,false,false url: https://t.co/i/adsct cookieFound: true,true,true,true
  passed: true,true,true,true url: https://t.co/i/adsct cookieFound: false,false,false,false
  passed: true,true,true,true url: https://t.co/i/adsct cookieFound: false,false,false,false
  passed: true,true,true,true url: https://t.co/i/adsct cookieFound: false,false,false,false
  passed: true,true,true,true url: https://t.co/i/adsct cookieFound: false,false,false,false
  passed: true,true,true,true url: https://t.co/i/adsct cookieFound: false,false,false,false
  passed: true,true,true,true url: https://t.co/i/adsct cookieFound: false,false,false,false
  passed: true,true,true,true url: https://t.co/i/adsct cookieFound: false,false,false,false
  passed: true,true,true,true url: https://t.co/i/adsct cookieFound: false,false,false,false
Yandex AdsTests whether the browser stops cookies from yandex.ru from tracking users across websites.
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
  passed: true,true,true,true url: https://yandex.ru/ads/system/header-bidding.js cookieFound: false,false,false,false
Cross-session first-party tracking tests Which 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-SvcAlt-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.
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h3, h3, h3, h3 result, different session: h2, h2, h2, h2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h3, h3, h3, h3 result, different session: h2, h2, h2, h2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h3, h3, h3, h3 result, different session: h2, h2, h2, h2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h3, h3, h3, h3 result, different session: h2, h2, h2, h2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h3, h3, h3, h3 result, different session: h2, h2, h2, h2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h3, h3, h3, h3 result, different session: h2, h2, h2, h2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h3, h3, h3, h3 result, different session: h2, h2, h2, h2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h3, h3, h3, h3 result, different session: h2, h2, h2, h2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h3, h3, h3, h3 result, different session: h2, h2, h2, h2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
CacheStorageThe 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.
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: d91ebb72-df9c-4f41-95b5-60e241890671_1p, 3a97209b-1788-4386-a100-c1f080f208ed_1p, 5220841f-fa5d-41c4-8328-9c0b0a79663c_1p, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_1p result, different session: Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url') unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: 01e86091-e4d2-426d-8107-14b24f9d3c32_1p, 53f6f750-08ee-4fff-9e9f-9727a6546c57_1p, 67c74d28-b18c-480d-82a4-026d6c7113dd_1p, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9_1p result, different session: Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url') unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_1p, 60422fe9-a24b-4999-b491-7ab178c79ad3_1p, 5fc445e2-97c0-406e-b955-2cf486b66d02_1p, f55fb1ed-8d31-46a3-a27f-4c03925b604e_1p result, different session: Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url') unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990_1p, 486753ac-5ee1-4845-914e-b4d447cdd0d9_1p, 7cd6bf02-0547-450d-8c9c-6ce3a6470342_1p, 919dfb09-a069-466e-a150-77755c21db77_1p result, different session: Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url') unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') result, different session: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: 59caff2f-a419-4ac4-b969-e861161dfbf7_1p, 788cdb07-a775-4451-a85f-b542851f8a4c_1p, 39ca5981-befe-4339-a896-569a4c66ad80_1p, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4_1p result, different session: Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url') unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2_1p, 913a2832-170f-4e90-854d-7280946144ab_1p, c28a7953-008f-4fa5-8e15-12750255bf16_1p, 00124808-29a4-4b8b-9477-b17c1f0fcac4_1p result, different session: Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url') unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
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.
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: d91ebb72-df9c-4f41-95b5-60e241890671_1p_http, 3a97209b-1788-4386-a100-c1f080f208ed_1p_http, 5220841f-fa5d-41c4-8328-9c0b0a79663c_1p_http, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_1p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 01e86091-e4d2-426d-8107-14b24f9d3c32_1p_http, 53f6f750-08ee-4fff-9e9f-9727a6546c57_1p_http, 67c74d28-b18c-480d-82a4-026d6c7113dd_1p_http, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9_1p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_1p_http, 60422fe9-a24b-4999-b491-7ab178c79ad3_1p_http, 5fc445e2-97c0-406e-b955-2cf486b66d02_1p_http, f55fb1ed-8d31-46a3-a27f-4c03925b604e_1p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 9915b131-e392-4f54-b0b0-10a779442cd9_1p_http, 2c6f0997-321a-4990-98e3-9bed415fdfab_1p_http, a0f5c861-68a9-4067-912e-e3ac29777cfe_1p_http, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186_1p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 1627bda0-b530-4117-8513-ed73801416d1_1p_http, 968ea873-db17-4bf2-be9d-341c797feae5_1p_http, 4156389a-5349-4c89-8b67-8f62b9932e06_1p_http, 418fa667-dc9d-41db-807c-d08a0ae12221_1p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: b2e80bd9-c5cc-4808-b316-200e35e0a990_1p_http, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5_1p_http, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3_1p_http, 46b41978-e872-4efc-aa6a-4087cd8587d8_1p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990_1p_http, 486753ac-5ee1-4845-914e-b4d447cdd0d9_1p_http, 7cd6bf02-0547-450d-8c9c-6ce3a6470342_1p_http, 919dfb09-a069-466e-a150-77755c21db77_1p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 0e46c989-a36b-4473-b145-4d119e50d1b3_1p_http, f67c8512-8836-4bb8-aa5a-29e094c3eca8_1p_http, 3a3b164e-50cd-4baf-b2e8-e8375f83b300_1p_http, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469_1p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 59caff2f-a419-4ac4-b969-e861161dfbf7_1p_http, 788cdb07-a775-4451-a85f-b542851f8a4c_1p_http, 39ca5981-befe-4339-a896-569a4c66ad80_1p_http, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4_1p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2_1p_http, 913a2832-170f-4e90-854d-7280946144ab_1p_http, c28a7953-008f-4fa5-8e15-12750255bf16_1p_http, 00124808-29a4-4b8b-9477-b17c1f0fcac4_1p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
cookie (JS)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: d91ebb72-df9c-4f41-95b5-60e241890671_1p_js, 3a97209b-1788-4386-a100-c1f080f208ed_1p_js, 5220841f-fa5d-41c4-8328-9c0b0a79663c_1p_js, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_1p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 01e86091-e4d2-426d-8107-14b24f9d3c32_1p_js, 53f6f750-08ee-4fff-9e9f-9727a6546c57_1p_js, 67c74d28-b18c-480d-82a4-026d6c7113dd_1p_js, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9_1p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_1p_js, 60422fe9-a24b-4999-b491-7ab178c79ad3_1p_js, 5fc445e2-97c0-406e-b955-2cf486b66d02_1p_js, f55fb1ed-8d31-46a3-a27f-4c03925b604e_1p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 9915b131-e392-4f54-b0b0-10a779442cd9_1p_js, 2c6f0997-321a-4990-98e3-9bed415fdfab_1p_js, a0f5c861-68a9-4067-912e-e3ac29777cfe_1p_js, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186_1p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 1627bda0-b530-4117-8513-ed73801416d1_1p_js, 968ea873-db17-4bf2-be9d-341c797feae5_1p_js, 4156389a-5349-4c89-8b67-8f62b9932e06_1p_js, 418fa667-dc9d-41db-807c-d08a0ae12221_1p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: b2e80bd9-c5cc-4808-b316-200e35e0a990_1p_js, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5_1p_js, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3_1p_js, 46b41978-e872-4efc-aa6a-4087cd8587d8_1p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990_1p_js, 486753ac-5ee1-4845-914e-b4d447cdd0d9_1p_js, 7cd6bf02-0547-450d-8c9c-6ce3a6470342_1p_js, 919dfb09-a069-466e-a150-77755c21db77_1p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 0e46c989-a36b-4473-b145-4d119e50d1b3_1p_js, f67c8512-8836-4bb8-aa5a-29e094c3eca8_1p_js, 3a3b164e-50cd-4baf-b2e8-e8375f83b300_1p_js, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469_1p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 59caff2f-a419-4ac4-b969-e861161dfbf7_1p_js, 788cdb07-a775-4451-a85f-b542851f8a4c_1p_js, 39ca5981-befe-4339-a896-569a4c66ad80_1p_js, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4_1p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2_1p_js, 913a2832-170f-4e90-854d-7280946144ab_1p_js, c28a7953-008f-4fa5-8e15-12750255bf16_1p_js, 00124808-29a4-4b8b-9477-b17c1f0fcac4_1p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
CookieStoreThe Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.
  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: d91ebb72-df9c-4f41-95b5-60e241890671_1p, 3a97209b-1788-4386-a100-c1f080f208ed_1p, 5220841f-fa5d-41c4-8328-9c0b0a79663c_1p, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  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: 01e86091-e4d2-426d-8107-14b24f9d3c32_1p, 53f6f750-08ee-4fff-9e9f-9727a6546c57_1p, 67c74d28-b18c-480d-82a4-026d6c7113dd_1p, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  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: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_1p, 60422fe9-a24b-4999-b491-7ab178c79ad3_1p, 5fc445e2-97c0-406e-b955-2cf486b66d02_1p, f55fb1ed-8d31-46a3-a27f-4c03925b604e_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  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: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990_1p, 486753ac-5ee1-4845-914e-b4d447cdd0d9_1p, 7cd6bf02-0547-450d-8c9c-6ce3a6470342_1p, 919dfb09-a069-466e-a150-77755c21db77_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  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: 59caff2f-a419-4ac4-b969-e861161dfbf7_1p, 788cdb07-a775-4451-a85f-b542851f8a4c_1p, 39ca5981-befe-4339-a896-569a4c66ad80_1p, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  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: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2_1p, 913a2832-170f-4e90-854d-7280946144ab_1p, c28a7953-008f-4fa5-8e15-12750255bf16_1p, 00124808-29a4-4b8b-9477-b17c1f0fcac4_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
CSS cacheCSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_8261133250591257, fake_8391438329233238, fake_7431737032246748, fake_22118887766118545 result, different session: fake_3438033946458561, fake_48211571642199647, fake_8858657334702134, fake_38653995172723477 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_04957162536125015, fake_08606167442496071, fake_4069728281752887, fake_023279106835950136 result, different session: fake_7629135552205182, fake_861382993100289, fake_32270778738943817, fake_49118614651815573 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_5886148556083495, fake_24213111204593996, fake_03570166242809747, fake_7875146806603501 result, different session: fake_8691656914540673, fake_31732213070086623, fake_8150603717935487, fake_3385730485572134 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_29459738784574085, fake_42372425192604735, fake_6116501402228061, fake_5364937735476512 result, different session: fake_4201747560541076, fake_9757848069329458, fake_5575357113116992, fake_8963749469700499 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_6673314492314133, fake_41943211360719634, fake_8931175365988586, fake_46717392021767234 result, different session: fake_4937363829942132, fake_17026621886093696, fake_5385493914101667, fake_7074541589417691 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_46340836779735217, fake_06598494213177641, fake_6917088513660117, fake_7150041182662585 result, different session: fake_8416971233400687, fake_6562089203197317, fake_8856660768750617, fake_1205973077569753 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_028214434796784538, fake_14817676742176866, fake_6286660191255273, fake_22217916909685131 result, different session: fake_38698571070038024, fake_8525754440291036, fake_463685291750924, fake_7440893946539786 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_22609364872931148, fake_6828083786714438, fake_07091278719189864, fake_5268551990220309 result, different session: fake_4590460146387296, fake_4870654633545648, fake_7507131298612106, fake_7468818347688302 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_1075456829873247, fake_08698297567736724, fake_8178329130341144, fake_21651541657851037 result, different session: fake_36531245706864657, fake_07655431187472717, fake_8206110008147149, fake_23859131731919248 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_9698341806622381, fake_8588191746371119, fake_6787960470803251, fake_24670612506941736 result, different session: fake_4508909645245178, fake_1857565569311479, fake_018197157574999068, fake_06130356149356175 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_2380236024213913, fake_9677835529884176, fake_4371684047968514, fake_7956478352734695 result, different session: fake_5700303544471654, fake_9156083763567779, fake_2775930373268216, fake_9621251923866352 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
favicon cacheA 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.
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 2, 2, 2, 2 result, different session: 4, 4, 4, 4 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
fetch cacheWhen a resource is received via the Fetch API, it is frequently cached. That cache can potentially be abused for cross-site tracking.
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
font cacheWeb fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
iframe cacheAn 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.
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
image cacheCaching of images in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
indexedDBThe IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: d91ebb72-df9c-4f41-95b5-60e241890671_1p, 3a97209b-1788-4386-a100-c1f080f208ed_1p, 5220841f-fa5d-41c4-8328-9c0b0a79663c_1p, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_1p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: 01e86091-e4d2-426d-8107-14b24f9d3c32_1p, 53f6f750-08ee-4fff-9e9f-9727a6546c57_1p, 67c74d28-b18c-480d-82a4-026d6c7113dd_1p, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9_1p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_1p, 60422fe9-a24b-4999-b491-7ab178c79ad3_1p, 5fc445e2-97c0-406e-b955-2cf486b66d02_1p, f55fb1ed-8d31-46a3-a27f-4c03925b604e_1p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: 9915b131-e392-4f54-b0b0-10a779442cd9_1p, 2c6f0997-321a-4990-98e3-9bed415fdfab_1p, a0f5c861-68a9-4067-912e-e3ac29777cfe_1p, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186_1p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: 1627bda0-b530-4117-8513-ed73801416d1_1p, 968ea873-db17-4bf2-be9d-341c797feae5_1p, 4156389a-5349-4c89-8b67-8f62b9932e06_1p, 418fa667-dc9d-41db-807c-d08a0ae12221_1p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations. result, different session: Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990_1p, 486753ac-5ee1-4845-914e-b4d447cdd0d9_1p, 7cd6bf02-0547-450d-8c9c-6ce3a6470342_1p, 919dfb09-a069-466e-a150-77755c21db77_1p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: undefined result, different session: undefined unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations. result, different session: Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations., Error: A mutation operation was attempted on a database that did not allow mutations. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: 59caff2f-a419-4ac4-b969-e861161dfbf7_1p, 788cdb07-a775-4451-a85f-b542851f8a4c_1p, 39ca5981-befe-4339-a896-569a4c66ad80_1p, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4_1p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2_1p, 913a2832-170f-4e90-854d-7280946144ab_1p, c28a7953-008f-4fa5-8e15-12750255bf16_1p, 00124808-29a4-4b8b-9477-b17c1f0fcac4_1p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
localStorageThe 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.
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: d91ebb72-df9c-4f41-95b5-60e241890671_1p, 3a97209b-1788-4386-a100-c1f080f208ed_1p, 5220841f-fa5d-41c4-8328-9c0b0a79663c_1p, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 01e86091-e4d2-426d-8107-14b24f9d3c32_1p, 53f6f750-08ee-4fff-9e9f-9727a6546c57_1p, 67c74d28-b18c-480d-82a4-026d6c7113dd_1p, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_1p, 60422fe9-a24b-4999-b491-7ab178c79ad3_1p, 5fc445e2-97c0-406e-b955-2cf486b66d02_1p, f55fb1ed-8d31-46a3-a27f-4c03925b604e_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 9915b131-e392-4f54-b0b0-10a779442cd9_1p, 2c6f0997-321a-4990-98e3-9bed415fdfab_1p, a0f5c861-68a9-4067-912e-e3ac29777cfe_1p, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 1627bda0-b530-4117-8513-ed73801416d1_1p, 968ea873-db17-4bf2-be9d-341c797feae5_1p, 4156389a-5349-4c89-8b67-8f62b9932e06_1p, 418fa667-dc9d-41db-807c-d08a0ae12221_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: b2e80bd9-c5cc-4808-b316-200e35e0a990_1p, 996b0b8c-6353-4213-b5cc-14ca48e9e5c5_1p, 8d81517f-ddcc-4b76-95d5-f08ab58a5aa3_1p, 46b41978-e872-4efc-aa6a-4087cd8587d8_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990_1p, 486753ac-5ee1-4845-914e-b4d447cdd0d9_1p, 7cd6bf02-0547-450d-8c9c-6ce3a6470342_1p, 919dfb09-a069-466e-a150-77755c21db77_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 0e46c989-a36b-4473-b145-4d119e50d1b3_1p, f67c8512-8836-4bb8-aa5a-29e094c3eca8_1p, 3a3b164e-50cd-4baf-b2e8-e8375f83b300_1p, 4c1f1966-f9e9-4aec-b90b-9ec7eff63469_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 59caff2f-a419-4ac4-b969-e861161dfbf7_1p, 788cdb07-a775-4451-a85f-b542851f8a4c_1p, 39ca5981-befe-4339-a896-569a4c66ad80_1p, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2_1p, 913a2832-170f-4e90-854d-7280946144ab_1p, c28a7953-008f-4fa5-8e15-12750255bf16_1p, 00124808-29a4-4b8b-9477-b17c1f0fcac4_1p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
prefetch cacheA 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.
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
Web SQL DatabaseThe Web SQL Database is a deprecated web API for storing data in an SQL database.
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: d91ebb72-df9c-4f41-95b5-60e241890671_1p, 3a97209b-1788-4386-a100-c1f080f208ed_1p, 5220841f-fa5d-41c4-8328-9c0b0a79663c_1p, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_1p result, different session: Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache) unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: 01e86091-e4d2-426d-8107-14b24f9d3c32_1p, 53f6f750-08ee-4fff-9e9f-9727a6546c57_1p, 67c74d28-b18c-480d-82a4-026d6c7113dd_1p, 2ff6b49f-fc5e-4c08-a813-72bd4e80e1c9_1p result, different session: Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache) unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_1p, 60422fe9-a24b-4999-b491-7ab178c79ad3_1p, 5fc445e2-97c0-406e-b955-2cf486b66d02_1p, f55fb1ed-8d31-46a3-a27f-4c03925b604e_1p result, different session: Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache) unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: 0c85c8dc-0ed1-4868-9abb-1b1b1adcb990_1p, 486753ac-5ee1-4845-914e-b4d447cdd0d9_1p, 7cd6bf02-0547-450d-8c9c-6ce3a6470342_1p, 919dfb09-a069-466e-a150-77755c21db77_1p result, different session: Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache) unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated result, different session: Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: 59caff2f-a419-4ac4-b969-e861161dfbf7_1p, 788cdb07-a775-4451-a85f-b542851f8a4c_1p, 39ca5981-befe-4339-a896-569a4c66ad80_1p, a29461a4-0ca6-4c51-bc4d-fc9724ce55b4_1p result, different session: Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache) unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: ad2b1c50-b8ae-4eac-9a5f-82fcc84f2ac2_1p, 913a2832-170f-4e90-854d-7280946144ab_1p, c28a7953-008f-4fa5-8e15-12750255bf16_1p, 00124808-29a4-4b8b-9477-b17c1f0fcac4_1p result, different session: Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache), Error: could not prepare statement (1 no such table: cache) unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
XMLHttpRequest cacheSimilar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
Cross-session third-party tracking tests Which 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-SvcAlt-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.
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/clear"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache for (let i = 0; i < 3; ++i) { await fetch(altSvcOrigin + "/set"); await sleepMs(100); } responseText = await fetchText(altSvcOrigin + "/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText(altSvcOrigin + "/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same session: h2, h2, h2, h2 result, different session: h2, h2, h2, h2 unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
CacheStorageThe 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.
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. result, different session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. result, different session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_3p, 60422fe9-a24b-4999-b491-7ab178c79ad3_3p, 5fc445e2-97c0-406e-b955-2cf486b66d02_3p, f55fb1ed-8d31-46a3-a27f-4c03925b604e_3p result, different session: Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url'), Error: Cannot read properties of undefined (reading 'url') unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. result, different session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), 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') unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. result, different session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. result, different session: Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent., Error: Failed to execute 'open' on 'CacheStorage': An attempt was made to break through the security policy of the user agent. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
cookie (HTTP)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: d91ebb72-df9c-4f41-95b5-60e241890671_3p_http, 3a97209b-1788-4386-a100-c1f080f208ed_3p_http, 5220841f-fa5d-41c4-8328-9c0b0a79663c_3p_http, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_3p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_3p_http, 60422fe9-a24b-4999-b491-7ab178c79ad3_3p_http, 5fc445e2-97c0-406e-b955-2cf486b66d02_3p_http, f55fb1ed-8d31-46a3-a27f-4c03925b604e_3p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 9915b131-e392-4f54-b0b0-10a779442cd9_3p_http, 2c6f0997-321a-4990-98e3-9bed415fdfab_3p_http, a0f5c861-68a9-4067-912e-e3ac29777cfe_3p_http, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186_3p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 1627bda0-b530-4117-8513-ed73801416d1_3p_http, 968ea873-db17-4bf2-be9d-341c797feae5_3p_http, 4156389a-5349-4c89-8b67-8f62b9932e06_3p_http, 418fa667-dc9d-41db-807c-d08a0ae12221_3p_http result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
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.
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: d91ebb72-df9c-4f41-95b5-60e241890671_3p_js, 3a97209b-1788-4386-a100-c1f080f208ed_3p_js, 5220841f-fa5d-41c4-8328-9c0b0a79663c_3p_js, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_3p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_3p_js, 60422fe9-a24b-4999-b491-7ab178c79ad3_3p_js, 5fc445e2-97c0-406e-b955-2cf486b66d02_3p_js, f55fb1ed-8d31-46a3-a27f-4c03925b604e_3p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 9915b131-e392-4f54-b0b0-10a779442cd9_3p_js, 2c6f0997-321a-4990-98e3-9bed415fdfab_3p_js, a0f5c861-68a9-4067-912e-e3ac29777cfe_3p_js, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186_3p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 1627bda0-b530-4117-8513-ed73801416d1_3p_js, 968ea873-db17-4bf2-be9d-341c797feae5_3p_js, 4156389a-5349-4c89-8b67-8f62b9932e06_3p_js, 418fa667-dc9d-41db-807c-d08a0ae12221_3p_js result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
CookieStoreThe Cookie Store API is an alternative asynchronous API for managing cookies, supported by some browsers.
  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: d91ebb72-df9c-4f41-95b5-60e241890671_3p, 3a97209b-1788-4386-a100-c1f080f208ed_3p, 5220841f-fa5d-41c4-8328-9c0b0a79663c_3p, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_3p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
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 passed: undefined test failed: false, false, false, false
  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: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_3p, 60422fe9-a24b-4999-b491-7ab178c79ad3_3p, 5fc445e2-97c0-406e-b955-2cf486b66d02_3p, f55fb1ed-8d31-46a3-a27f-4c03925b604e_3p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
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 passed: undefined test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
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 passed: undefined test failed: false, false, false, false
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 passed: undefined test failed: false, false, false, false
CSS cacheCSS stylesheets are cached, and if that cache is shared between websites, it can be used to track users across sites.
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_12876710107320566, fake_06474991024168664, fake_5968320641433782, fake_9493399646279879 result, different session: fake_6906248063195455, fake_3280769787485527, fake_7534361087049222, fake_601689824773215 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_11297976186996328, fake_581268094165718, fake_7789798999984339, fake_8027394348795336 result, different session: fake_7472527105285405, fake_7552591504194981, fake_2862932716842119, fake_601455155063249 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_9085385597122198, fake_7906957156028047, fake_39836205518288437, fake_918535593281633 result, different session: fake_8290273974345861, fake_9363434897096428, fake_9414710368433694, fake_6776221611217725 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_6322161763407914, fake_2978886641167926, fake_6889647605957123, fake_7902327687075992 result, different session: fake_9892914960537371, fake_8935082852846121, fake_9312712708766877, fake_9741400344100772 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_21562963123002876, fake_5943925048374192, fake_07818415602007844, fake_5403822302416863 result, different session: fake_8925045554485131, fake_9932724291152188, fake_5048092364820504, fake_29615681500441315 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_8958739581228068, fake_42495297402014676, fake_9935820665337012, fake_694370642184984 result, different session: fake_8743635829238943, fake_40084740116276585, fake_34287648390199377, fake_7891754575070773 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_5309895599220711, fake_6355636559434064, fake_4993965582066464, fake_6232087546344816 result, different session: fake_4003518515805191, fake_5444045005368914, fake_6363896873929997, fake_06321289021712495 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_6161593488343584, fake_8747957221164044, fake_08087950750676454, fake_23966520593691 result, different session: fake_3690298768437139, fake_9236419933403033, fake_9716625205129459, fake_8390497478228742 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_7627288944925812, fake_4368647283109284, fake_9775562329414795, fake_29147535039210837 result, different session: fake_5092622183887425, fake_4217259100927244, fake_7221353148432512, fake_8263328435384794 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_453752227241774, fake_0983103718912095, fake_741899548359289, fake_1251316214171958 result, different session: fake_7890390996092393, fake_7246339491598601, fake_925196025414943, fake_0599164304535198 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return key; } read: async (key) => { const href = testURI("resource", "css", key); const head = document.getElementsByTagName("head")[0]; head.innerHTML += `<link type="text/css" rel="stylesheet" href="${href}">`; const testElement = document.querySelector("#css"); let fontFamily; while (true) { await sleepMs(100); fontFamily = getComputedStyle(testElement).fontFamily; if (fontFamily.startsWith("fake")) { break; } } console.log(fontFamily); return fontFamily; } result, same session: fake_8983832810173207, fake_7390873699516278, fake_5724338548448786, fake_1412693697412446 result, different session: fake_917347497366005, fake_020676102961656895, fake_7365023556312553, fake_16049672588763153 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
favicon cacheA 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.
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 2, 2, 2, 2 result, different session: 4, 4, 4, 4 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
fetch cacheWhen a resource is received via the Fetch API, it is frequently cached. That cache can potentially be abused for cross-site tracking.
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
font cacheWeb fonts are sometimes stored in their own cache, which is vulnerable to being abused for cross-site tracking.
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
iframe cacheAn 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.
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
image cacheCaching of images in web browsers is a standard behavior. But if that cache leaks between websites, it can be abused for cross-site tracking.
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
indexedDBThe IndexedDB API exposes a transactional database to web pages. That database can be used to track users across websites, unless it is partitioned.
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. result, different session: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. result, different session: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_3p, 60422fe9-a24b-4999-b491-7ab178c79ad3_3p, 5fc445e2-97c0-406e-b955-2cf486b66d02_3p, f55fb1ed-8d31-46a3-a27f-4c03925b604e_3p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: 9915b131-e392-4f54-b0b0-10a779442cd9_3p, 2c6f0997-321a-4990-98e3-9bed415fdfab_3p, a0f5c861-68a9-4067-912e-e3ac29777cfe_3p, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186_3p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: 1627bda0-b530-4117-8513-ed73801416d1_3p, 968ea873-db17-4bf2-be9d-341c797feae5_3p, 4156389a-5349-4c89-8b67-8f62b9932e06_3p, 418fa667-dc9d-41db-807c-d08a0ae12221_3p result, different session: undefined unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. result, different session: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: undefined result, different session: undefined unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. result, different session: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (secret) => { try { return await IdbKeyVal.set("secret", secret); } catch (e) { throw new Error("Unsupported"); } } read: () => IdbKeyVal.get("secret") result, same session: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. result, different session: Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database., Error: The user denied permission to access the database. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
localStorageThe 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.
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: d91ebb72-df9c-4f41-95b5-60e241890671_3p, 3a97209b-1788-4386-a100-c1f080f208ed_3p, 5220841f-fa5d-41c4-8328-9c0b0a79663c_3p, ea3ce35d-be5c-40cf-b8e0-ef191a4753c7_3p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. result, different session: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 8848d48e-6d6d-4e5c-a2f3-206e1586a312_3p, 60422fe9-a24b-4999-b491-7ab178c79ad3_3p, 5fc445e2-97c0-406e-b955-2cf486b66d02_3p, f55fb1ed-8d31-46a3-a27f-4c03925b604e_3p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 9915b131-e392-4f54-b0b0-10a779442cd9_3p, 2c6f0997-321a-4990-98e3-9bed415fdfab_3p, a0f5c861-68a9-4067-912e-e3ac29777cfe_3p, 07c63936-e6c6-4ad3-91e0-e0bcd7a67186_3p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 1627bda0-b530-4117-8513-ed73801416d1_3p, 968ea873-db17-4bf2-be9d-341c797feae5_3p, 4156389a-5349-4c89-8b67-8f62b9932e06_3p, 418fa667-dc9d-41db-807c-d08a0ae12221_3p result, different session: , , , unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. result, different session: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: , , , result, different session: , , , unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. result, different session: Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure., Error: The operation is insecure. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. result, different session: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. result, different session: Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document., Error: Failed to read the 'localStorage' property from 'Window': Access is denied for this document. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
prefetch cacheA 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.
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 1, 1, 1, 1 unsupported: false, false, false, false passed: false, false, false, false test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
Web SQL DatabaseThe Web SQL Database is a deprecated web API for storing data in an SQL database.
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. result, different session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. result, different session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. result, different session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. result, different session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated result, different session: Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated, Error: Web SQL is deprecated unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function result, different session: Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function, Error: window.openDatabase is not a function unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. result, different session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
write: async (key) => { if (!window.openDatabase) { throw new Error("gported"); } let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let tx = new Promise((resolve) => database.transaction(tx => { tx.executeSql( `CREATE TABLE IF NOT EXISTS cache( id INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, value TEXT NOT NULL, UNIQUE (name) )`, [], (tx, rs) => {}, (tx, err) => {}); tx.executeSql( `INSERT OR REPLACE INTO cache(name, value) VALUES(?, ?)`, ["secret", key], (tx, rs) => {}, (tx, rs) => {}); })); } read: async () => { let database = window.openDatabase("sqlite_supercookie", "", "supercookie", 1024 * 1024); let result = await new Promise((resolve, reject) => database.transaction(tx => { tx.executeSql( "SELECT value FROM cache WHERE name=?", ["secret"], (tx, rs) => resolve(rs), (tx, err) => reject(err)); })); return result.rows.item(0).value; } result, same session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. result, different session: Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts., Error: Failed to execute 'openDatabase' on 'Window': Access to the WebDatabase API is denied in third party contexts. unsupported: true, true, true, true passed: undefined test failed: false, false, false, false
XMLHttpRequest cacheSimilar to the newer Fetch API, any resource received may be cached by the browser. The cache is potentially vulnerable to cross-site tracking attack.
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 2, 2, 2, 2 result, different session: 3, 3, 3, 3 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1 result, different session: 2, 2, 2, 2 unsupported: false, false, false, false passed: true, true, true, true test failed: false, false, false, false