iOS Browsers

(default settings)

brave
1.57

chrome
117.5938

duckduckgo
7.91

edge
116.1938

firefox
118.1

focus
118.0

opera
4.3

safari
17.0

vivaldi
6.3137

yandex
2309.5
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, Error: Unsupported result, different first party: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, Error: Unsupported result, different first party: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, Error: Unsupported result, different first party: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, Error: Unsupported result, different first party: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, Error: Unsupported result, different first party: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, Error: Unsupported result, different first party: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, Error: Unsupported result, different first party: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, Error: Unsupported result, different first party: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, Error: Unsupported result, different first party: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, Error: Unsupported result, different first party: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 9ac39a85-8ab7-4701-a180-e0258ffed06d, c8bec77d-63ba-4341-917e-b5408c92dcc5, 042d8f53-c559-43a6-a8a7-47ddc37130bd, 85f1f68b-7073-4597-b535-eb74b80aadd1, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 result, different first party: 9ac39a85-8ab7-4701-a180-e0258ffed06d, c8bec77d-63ba-4341-917e-b5408c92dcc5, 042d8f53-c559-43a6-a8a7-47ddc37130bd, 85f1f68b-7073-4597-b535-eb74b80aadd1, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701, d34c57c7-5d97-4e88-914b-e48338759e2a, f06fc2c4-1496-40d7-845d-8ece8392ef42, 61475483-e492-4381-8454-dd307e85da96, 52fa6d5a-aeff-4339-89d9-416078067571 result, different first party: ecd8774e-b3ff-41e4-95e4-1f4d6a473701, d34c57c7-5d97-4e88-914b-e48338759e2a, f06fc2c4-1496-40d7-845d-8ece8392ef42, 61475483-e492-4381-8454-dd307e85da96, 52fa6d5a-aeff-4339-89d9-416078067571 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 622f476f-496f-479a-8210-d893d45008e3, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, 100e6983-45f4-461c-b471-82142ccb28cd, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e result, different first party: 622f476f-496f-479a-8210-d893d45008e3, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, 100e6983-45f4-461c-b471-82142ccb28cd, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${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: 85251b22-cbd9-4601-86ba-3b4c577c26c1, 99137440-3c3f-4062-b7b6-b8b5656fe3e3, 326d2d25-8350-4dda-9fd0-47313dcd2617, e70d9262-de62-48cc-9f39-32381c778d9d, 31abe5a2-5672-4dbb-8117-f5bd46034efe result, different first party: 85251b22-cbd9-4601-86ba-3b4c577c26c1, 99137440-3c3f-4062-b7b6-b8b5656fe3e3, 326d2d25-8350-4dda-9fd0-47313dcd2617, e70d9262-de62-48cc-9f39-32381c778d9d, 31abe5a2-5672-4dbb-8117-f5bd46034efe unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 4ba06d12-1bda-476e-9b5d-64a1e308d511, 3deec293-7da9-484f-9c66-ef3e09af2d78, d9848e10-1748-434d-bc7a-875a9ebb9509, 4452583e-047f-42e6-a3ed-e10ee6e982fe, 479d2517-702a-4d44-916c-2d5a02f1c810 result, different first party: 4ba06d12-1bda-476e-9b5d-64a1e308d511, 3deec293-7da9-484f-9c66-ef3e09af2d78, d9848e10-1748-434d-bc7a-875a9ebb9509, 4452583e-047f-42e6-a3ed-e10ee6e982fe, 479d2517-702a-4d44-916c-2d5a02f1c810 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${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, Error: Load failed result, different first party: Error: Load failed, Error: Load failed, Error: Load failed, Error: Load failed, Error: Load failed unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
  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=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 08da9409-753a-47f6-b943-3eb2da2e5f43, 33078437-5ab2-47db-8711-876cffa90f94, f2b1405c-9823-481d-a5f1-9523a11a5dce, 6fea33c4-c1e6-4894-882d-67ab5486a325, 62b540c8-6950-43b3-a590-520b11bc8039 result, different first party: 08da9409-753a-47f6-b943-3eb2da2e5f43, 33078437-5ab2-47db-8711-876cffa90f94, f2b1405c-9823-481d-a5f1-9523a11a5dce, 6fea33c4-c1e6-4894-882d-67ab5486a325, 62b540c8-6950-43b3-a590-520b11bc8039 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, 121286d6-62fe-484f-8299-ffd8fd69ba14, fb9c38e8-5ae6-477a-ba7d-c9963e355902, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea result, different first party: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, 121286d6-62fe-484f-8299-ffd8fd69ba14, fb9c38e8-5ae6-477a-ba7d-c9963e355902, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: f7843a45-1904-4d46-84c1-f7a99c2a0667, c870d944-a0e7-4780-b7d2-de9964a7e828, 2aea4ed2-7103-4b43-b845-7479023e7c3c, debd74ae-cf0e-4c43-8f81-8525a239a8aa, f0af8fdf-b92b-4604-bcc8-060168311300 result, different first party: f7843a45-1904-4d46-84c1-f7a99c2a0667, c870d944-a0e7-4780-b7d2-de9964a7e828, 2aea4ed2-7103-4b43-b845-7479023e7c3c, debd74ae-cf0e-4c43-8f81-8525a239a8aa, f0af8fdf-b92b-4604-bcc8-060168311300 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${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: f3ed2451-6e30-4324-8498-a6d856dec785, 49ee8cd6-647b-49c8-adf1-766644f99437, 0e365bcc-4492-4d7a-b413-87412097f819, fb062a09-219d-404b-a2a8-c3d0dd55cf64, d9e3f96c-9618-4a86-a8b6-e344225ea20e result, different first party: f3ed2451-6e30-4324-8498-a6d856dec785, 49ee8cd6-647b-49c8-adf1-766644f99437, 0e365bcc-4492-4d7a-b413-87412097f819, fb062a09-219d-404b-a2a8-c3d0dd55cf64, d9e3f96c-9618-4a86-a8b6-e344225ea20e unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: 9ac39a85-8ab7-4701-a180-e0258ffed06d, c8bec77d-63ba-4341-917e-b5408c92dcc5, 042d8f53-c559-43a6-a8a7-47ddc37130bd, 85f1f68b-7073-4597-b535-eb74b80aadd1, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701, d34c57c7-5d97-4e88-914b-e48338759e2a, f06fc2c4-1496-40d7-845d-8ece8392ef42, 61475483-e492-4381-8454-dd307e85da96, 52fa6d5a-aeff-4339-89d9-416078067571 result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: 622f476f-496f-479a-8210-d893d45008e3, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, 100e6983-45f4-461c-b471-82142ccb28cd, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: 85251b22-cbd9-4601-86ba-3b4c577c26c1, 99137440-3c3f-4062-b7b6-b8b5656fe3e3, 326d2d25-8350-4dda-9fd0-47313dcd2617, e70d9262-de62-48cc-9f39-32381c778d9d, 31abe5a2-5672-4dbb-8117-f5bd46034efe result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: 4ba06d12-1bda-476e-9b5d-64a1e308d511, 3deec293-7da9-484f-9c66-ef3e09af2d78, d9848e10-1748-434d-bc7a-875a9ebb9509, 4452583e-047f-42e6-a3ed-e10ee6e982fe, 479d2517-702a-4d44-916c-2d5a02f1c810 result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, Error: no BroadcastChannel message result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
  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: 08da9409-753a-47f6-b943-3eb2da2e5f43, 33078437-5ab2-47db-8711-876cffa90f94, f2b1405c-9823-481d-a5f1-9523a11a5dce, 6fea33c4-c1e6-4894-882d-67ab5486a325, 62b540c8-6950-43b3-a590-520b11bc8039 result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, 121286d6-62fe-484f-8299-ffd8fd69ba14, fb9c38e8-5ae6-477a-ba7d-c9963e355902, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: f7843a45-1904-4d46-84c1-f7a99c2a0667, c870d944-a0e7-4780-b7d2-de9964a7e828, 2aea4ed2-7103-4b43-b845-7479023e7c3c, debd74ae-cf0e-4c43-8f81-8525a239a8aa, f0af8fdf-b92b-4604-bcc8-060168311300 result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: f3ed2451-6e30-4324-8498-a6d856dec785, 49ee8cd6-647b-49c8-adf1-766644f99437, 0e365bcc-4492-4d7a-b413-87412097f819, fb062a09-219d-404b-a2a8-c3d0dd55cf64, d9e3f96c-9618-4a86-a8b6-e344225ea20e result, different first party: Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message, Error: no BroadcastChannel message unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
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=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: 92038508-c686-42a4-861b-7f5193623665, 92038508-c686-42a4-861b-7f5193623665, 92038508-c686-42a4-861b-7f5193623665, 92038508-c686-42a4-861b-7f5193623665, 92038508-c686-42a4-861b-7f5193623665 result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: bfe54105-a171-4644-afda-f90524b3a5ea, bfe54105-a171-4644-afda-f90524b3a5ea, bfe54105-a171-4644-afda-f90524b3a5ea, bfe54105-a171-4644-afda-f90524b3a5ea, bfe54105-a171-4644-afda-f90524b3a5ea result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: 03bb465d-c5e3-4e09-9af9-344f09232c15, 03bb465d-c5e3-4e09-9af9-344f09232c15, 03bb465d-c5e3-4e09-9af9-344f09232c15, 03bb465d-c5e3-4e09-9af9-344f09232c15, 03bb465d-c5e3-4e09-9af9-344f09232c15 result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: ea480957-7cb0-40e9-a403-3ebe038c33ab, ea480957-7cb0-40e9-a403-3ebe038c33ab, ea480957-7cb0-40e9-a403-3ebe038c33ab, ea480957-7cb0-40e9-a403-3ebe038c33ab, ea480957-7cb0-40e9-a403-3ebe038c33ab result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: 658e6d92-bcb5-4aa8-a099-81c927e0a20c, 658e6d92-bcb5-4aa8-a099-81c927e0a20c, 658e6d92-bcb5-4aa8-a099-81c927e0a20c, 658e6d92-bcb5-4aa8-a099-81c927e0a20c, 658e6d92-bcb5-4aa8-a099-81c927e0a20c result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: 3a54a1a5-792e-4f11-97be-39175cd60d95, 3a54a1a5-792e-4f11-97be-39175cd60d95, 3a54a1a5-792e-4f11-97be-39175cd60d95, 3a54a1a5-792e-4f11-97be-39175cd60d95, 3a54a1a5-792e-4f11-97be-39175cd60d95 result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: f3886ddc-f78b-4d45-9d13-43ffdb7ae1a5, f3886ddc-f78b-4d45-9d13-43ffdb7ae1a5, f3886ddc-f78b-4d45-9d13-43ffdb7ae1a5, f3886ddc-f78b-4d45-9d13-43ffdb7ae1a5, f3886ddc-f78b-4d45-9d13-43ffdb7ae1a5 result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: f94a2bed-b91e-44c0-a465-b0ab4050575c, f94a2bed-b91e-44c0-a465-b0ab4050575c, f94a2bed-b91e-44c0-a465-b0ab4050575c, f94a2bed-b91e-44c0-a465-b0ab4050575c, f94a2bed-b91e-44c0-a465-b0ab4050575c result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: 463b4922-4edb-4a1a-a19b-d9f63985520d, 463b4922-4edb-4a1a-a19b-d9f63985520d, 463b4922-4edb-4a1a-a19b-d9f63985520d, 463b4922-4edb-4a1a-a19b-d9f63985520d, 463b4922-4edb-4a1a-a19b-d9f63985520d result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
cookie (HTTP)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
  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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 9ac39a85-8ab7-4701-a180-e0258ffed06d_http, c8bec77d-63ba-4341-917e-b5408c92dcc5_http, 042d8f53-c559-43a6-a8a7-47ddc37130bd_http, 85f1f68b-7073-4597-b535-eb74b80aadd1_http, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_http result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_http, d34c57c7-5d97-4e88-914b-e48338759e2a_http, f06fc2c4-1496-40d7-845d-8ece8392ef42_http, 61475483-e492-4381-8454-dd307e85da96_http, 52fa6d5a-aeff-4339-89d9-416078067571_http result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 622f476f-496f-479a-8210-d893d45008e3_http, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_http, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_http, 100e6983-45f4-461c-b471-82142ccb28cd_http, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_http result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: 85251b22-cbd9-4601-86ba-3b4c577c26c1_http, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_http, 326d2d25-8350-4dda-9fd0-47313dcd2617_http, e70d9262-de62-48cc-9f39-32381c778d9d_http, 31abe5a2-5672-4dbb-8117-f5bd46034efe_http result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 4ba06d12-1bda-476e-9b5d-64a1e308d511_http, 3deec293-7da9-484f-9c66-ef3e09af2d78_http, d9848e10-1748-434d-bc7a-875a9ebb9509_http, 4452583e-047f-42e6-a3ed-e10ee6e982fe_http, 479d2517-702a-4d44-916c-2d5a02f1c810_http result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: 5540e25b-012b-4070-9f09-14c82b3a2944_http, 93ebb577-e88b-4615-b2cc-ca6180e5fac5_http, 1b237b30-50d2-4301-912d-456f798b95b3_http, 3cd2a582-1831-4424-bfa6-c9d23d56df01_http, 52f72e7e-5a9d-48af-a650-bc2301651dea_http result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 08da9409-753a-47f6-b943-3eb2da2e5f43_http, 33078437-5ab2-47db-8711-876cffa90f94_http, f2b1405c-9823-481d-a5f1-9523a11a5dce_http, 6fea33c4-c1e6-4894-882d-67ab5486a325_http, 62b540c8-6950-43b3-a590-520b11bc8039_http result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_http, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_http, 121286d6-62fe-484f-8299-ffd8fd69ba14_http, fb9c38e8-5ae6-477a-ba7d-c9963e355902_http, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_http result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: f7843a45-1904-4d46-84c1-f7a99c2a0667_http, c870d944-a0e7-4780-b7d2-de9964a7e828_http, 2aea4ed2-7103-4b43-b845-7479023e7c3c_http, debd74ae-cf0e-4c43-8f81-8525a239a8aa_http, f0af8fdf-b92b-4604-bcc8-060168311300_http result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: f3ed2451-6e30-4324-8498-a6d856dec785_http, 49ee8cd6-647b-49c8-adf1-766644f99437_http, 0e365bcc-4492-4d7a-b413-87412097f819_http, fb062a09-219d-404b-a2a8-c3d0dd55cf64_http, d9e3f96c-9618-4a86-a8b6-e344225ea20e_http result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
cookie (JS)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 9ac39a85-8ab7-4701-a180-e0258ffed06d_js, c8bec77d-63ba-4341-917e-b5408c92dcc5_js, 042d8f53-c559-43a6-a8a7-47ddc37130bd_js, 85f1f68b-7073-4597-b535-eb74b80aadd1_js, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_js result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_js, d34c57c7-5d97-4e88-914b-e48338759e2a_js, f06fc2c4-1496-40d7-845d-8ece8392ef42_js, 61475483-e492-4381-8454-dd307e85da96_js, 52fa6d5a-aeff-4339-89d9-416078067571_js result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 622f476f-496f-479a-8210-d893d45008e3_js, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_js, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_js, 100e6983-45f4-461c-b471-82142ccb28cd_js, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_js result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 85251b22-cbd9-4601-86ba-3b4c577c26c1_js, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_js, 326d2d25-8350-4dda-9fd0-47313dcd2617_js, e70d9262-de62-48cc-9f39-32381c778d9d_js, 31abe5a2-5672-4dbb-8117-f5bd46034efe_js result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 4ba06d12-1bda-476e-9b5d-64a1e308d511_js, 3deec293-7da9-484f-9c66-ef3e09af2d78_js, d9848e10-1748-434d-bc7a-875a9ebb9509_js, 4452583e-047f-42e6-a3ed-e10ee6e982fe_js, 479d2517-702a-4d44-916c-2d5a02f1c810_js result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 5540e25b-012b-4070-9f09-14c82b3a2944_js, 93ebb577-e88b-4615-b2cc-ca6180e5fac5_js, 1b237b30-50d2-4301-912d-456f798b95b3_js, 3cd2a582-1831-4424-bfa6-c9d23d56df01_js, 52f72e7e-5a9d-48af-a650-bc2301651dea_js result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 08da9409-753a-47f6-b943-3eb2da2e5f43_js, 33078437-5ab2-47db-8711-876cffa90f94_js, f2b1405c-9823-481d-a5f1-9523a11a5dce_js, 6fea33c4-c1e6-4894-882d-67ab5486a325_js, 62b540c8-6950-43b3-a590-520b11bc8039_js result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_js, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_js, 121286d6-62fe-484f-8299-ffd8fd69ba14_js, fb9c38e8-5ae6-477a-ba7d-c9963e355902_js, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_js result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: f7843a45-1904-4d46-84c1-f7a99c2a0667_js, c870d944-a0e7-4780-b7d2-de9964a7e828_js, 2aea4ed2-7103-4b43-b845-7479023e7c3c_js, debd74ae-cf0e-4c43-8f81-8525a239a8aa_js, f0af8fdf-b92b-4604-bcc8-060168311300_js result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: f3ed2451-6e30-4324-8498-a6d856dec785_js, 49ee8cd6-647b-49c8-adf1-766644f99437_js, 0e365bcc-4492-4d7a-b413-87412097f819_js, fb062a09-219d-404b-a2a8-c3d0dd55cf64_js, d9e3f96c-9618-4a86-a8b6-e344225ea20e_js result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
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_8576303893802377, fake_11794589719049231, fake_34948735731705116, fake_8225120999041349, fake_3795620579067296 result, different first party: fake_466898107065457, fake_7683642688331973, fake_20072425951261574, fake_20584406129683752, fake_6692218398690848 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_7663595496209941, fake_46499032891027814, fake_3600480141209921, fake_9032610965715231, fake_008096720652093436 result, different first party: fake_77186609555895, fake_6869009412064049, fake_26150221772075555, fake_567962028313856, fake_09747107281505385 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_5820562561651237, fake_5384726738555232, fake_019407114895652944, fake_8332287293698812, fake_6803159409271637 result, different first party: fake_08245217913081015, fake_77579745271, fake_45716286874717693, fake_32522311548212945, fake_8112535358716702 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_8751145004069805, fake_7426914993314888, fake_11190014649885849, fake_5633439065186807, fake_6058610758564611 result, different first party: fake_7788775762263962, fake_3335382492912691, fake_9473772064905497, fake_09256510557085917, fake_05040521620972238 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_3020453572920647, fake_18680924998599013, fake_11791461390554048, fake_254263525409661, fake_6261726277585433 result, different first party: fake_3611883609878914, fake_3023562841766829, fake_43629753856472964, fake_39414747188448174, fake_5149260645510298 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_5567422022318413, fake_4346241065309815, fake_20978776874097704, fake_050606605042917474, fake_05520985457984806 result, different first party: fake_15372355576904884, fake_7587292278365732, fake_2679054703799564, fake_17793475997899644, fake_986404546784472 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_032122492238218836, fake_6464384410095458, fake_21661279796991617, fake_4157838761351431, fake_11160993992150359 result, different first party: fake_09068635783886969, fake_9724281724158619, fake_5040736923965616, fake_2963382455022321, fake_7675668632128982 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_10569481083208743, fake_7718205669018259, fake_4481809597828086, fake_3697745501145904, fake_5510775436654394 result, different first party: fake_05762100006295712, fake_05851206943906484, fake_4232262669618978, fake_7749964681469097, fake_06342482187895504 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_11936312538145177, fake_7002046879491302, fake_6318347915310967, fake_3759105954787667, fake_13976391653592812 result, different first party: fake_8550067481306916, fake_7696491828573033, fake_08313016833878062, fake_510941947002922, fake_9130779914279965 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_3417608753519876, fake_8182921097607005, fake_019890491038945246, fake_8712009719564753, fake_42048124506966955 result, different first party: fake_14488554473936044, fake_5989645227723455, fake_7399572659281919, fake_020046840092557305, fake_9664458851392999 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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, 1 result, different first party: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1, 1 result, different first party: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1, 1 result, different first party: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1, 1 result, different first party: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1, 1, 1, 1, 1 result, different first party: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different first party: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
fetch 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, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
font 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: 2, 2, 2, 2, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
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: , , , , result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt", { create: true }); const stream = await fileHandle.createWritable(); await stream.write(secret); await stream.close(); } catch (e) { throw new Error("Unsupported"); } } read: async () => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt"); const file = await fileHandle.getFile(); return file.text(); } catch (e) { throw new Error("Unsupported"); } } result, same first party: , , , , result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, 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: , , , , result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt", { create: true }); const stream = await fileHandle.createWritable(); await stream.write(secret); await stream.close(); } catch (e) { throw new Error("Unsupported"); } } read: async () => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt"); const file = await fileHandle.getFile(); return file.text(); } catch (e) { throw new Error("Unsupported"); } } result, same first party: , , , , result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, 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: , , , , result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt", { create: true }); const stream = await fileHandle.createWritable(); await stream.write(secret); await stream.close(); } catch (e) { throw new Error("Unsupported"); } } read: async () => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt"); const file = await fileHandle.getFile(); return file.text(); } catch (e) { throw new Error("Unsupported"); } } result, same first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt", { create: true }); const stream = await fileHandle.createWritable(); await stream.write(secret); await stream.close(); } catch (e) { throw new Error("Unsupported"); } } read: async () => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt"); const file = await fileHandle.getFile(); return file.text(); } catch (e) { throw new Error("Unsupported"); } } result, same first party: , , , , result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, 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: , , , , result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt", { create: true }); const stream = await fileHandle.createWritable(); await stream.write(secret); await stream.close(); } catch (e) { throw new Error("Unsupported"); } } read: async () => { try { const root = await navigator.storage.getDirectory(); const fileHandle = await root.getFileHandle("secret.txt"); const file = await fileHandle.getFile(); return file.text(); } catch (e) { throw new Error("Unsupported"); } } result, same first party: , , , , result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, 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: , , , , result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
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=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 9ac39a85-8ab7-4701-a180-e0258ffed06d, c8bec77d-63ba-4341-917e-b5408c92dcc5, 042d8f53-c559-43a6-a8a7-47ddc37130bd, 85f1f68b-7073-4597-b535-eb74b80aadd1, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701, d34c57c7-5d97-4e88-914b-e48338759e2a, f06fc2c4-1496-40d7-845d-8ece8392ef42, 61475483-e492-4381-8454-dd307e85da96, 52fa6d5a-aeff-4339-89d9-416078067571 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 622f476f-496f-479a-8210-d893d45008e3, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, 100e6983-45f4-461c-b471-82142ccb28cd, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: 85251b22-cbd9-4601-86ba-3b4c577c26c1, 99137440-3c3f-4062-b7b6-b8b5656fe3e3, 326d2d25-8350-4dda-9fd0-47313dcd2617, e70d9262-de62-48cc-9f39-32381c778d9d, 31abe5a2-5672-4dbb-8117-f5bd46034efe result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 4ba06d12-1bda-476e-9b5d-64a1e308d511, 3deec293-7da9-484f-9c66-ef3e09af2d78, d9848e10-1748-434d-bc7a-875a9ebb9509, 4452583e-047f-42e6-a3ed-e10ee6e982fe, 479d2517-702a-4d44-916c-2d5a02f1c810 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: 5540e25b-012b-4070-9f09-14c82b3a2944, 93ebb577-e88b-4615-b2cc-ca6180e5fac5, 1b237b30-50d2-4301-912d-456f798b95b3, 3cd2a582-1831-4424-bfa6-c9d23d56df01, 52f72e7e-5a9d-48af-a650-bc2301651dea result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 08da9409-753a-47f6-b943-3eb2da2e5f43, 33078437-5ab2-47db-8711-876cffa90f94, f2b1405c-9823-481d-a5f1-9523a11a5dce, 6fea33c4-c1e6-4894-882d-67ab5486a325, 62b540c8-6950-43b3-a590-520b11bc8039 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, 121286d6-62fe-484f-8299-ffd8fd69ba14, fb9c38e8-5ae6-477a-ba7d-c9963e355902, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: f7843a45-1904-4d46-84c1-f7a99c2a0667, c870d944-a0e7-4780-b7d2-de9964a7e828, 2aea4ed2-7103-4b43-b845-7479023e7c3c, debd74ae-cf0e-4c43-8f81-8525a239a8aa, f0af8fdf-b92b-4604-bcc8-060168311300 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: f3ed2451-6e30-4324-8498-a6d856dec785, 49ee8cd6-647b-49c8-adf1-766644f99437, 0e365bcc-4492-4d7a-b413-87412097f819, fb062a09-219d-404b-a2a8-c3d0dd55cf64, d9e3f96c-9618-4a86-a8b6-e344225ea20e result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 9ac39a85-8ab7-4701-a180-e0258ffed06d, c8bec77d-63ba-4341-917e-b5408c92dcc5, 042d8f53-c559-43a6-a8a7-47ddc37130bd, 85f1f68b-7073-4597-b535-eb74b80aadd1, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701, d34c57c7-5d97-4e88-914b-e48338759e2a, f06fc2c4-1496-40d7-845d-8ece8392ef42, 61475483-e492-4381-8454-dd307e85da96, 52fa6d5a-aeff-4339-89d9-416078067571 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 622f476f-496f-479a-8210-d893d45008e3, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, 100e6983-45f4-461c-b471-82142ccb28cd, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: 85251b22-cbd9-4601-86ba-3b4c577c26c1, 99137440-3c3f-4062-b7b6-b8b5656fe3e3, 326d2d25-8350-4dda-9fd0-47313dcd2617, e70d9262-de62-48cc-9f39-32381c778d9d, 31abe5a2-5672-4dbb-8117-f5bd46034efe result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 4ba06d12-1bda-476e-9b5d-64a1e308d511, 3deec293-7da9-484f-9c66-ef3e09af2d78, d9848e10-1748-434d-bc7a-875a9ebb9509, 4452583e-047f-42e6-a3ed-e10ee6e982fe, 479d2517-702a-4d44-916c-2d5a02f1c810 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: 5540e25b-012b-4070-9f09-14c82b3a2944, 93ebb577-e88b-4615-b2cc-ca6180e5fac5, 1b237b30-50d2-4301-912d-456f798b95b3, 3cd2a582-1831-4424-bfa6-c9d23d56df01, 52f72e7e-5a9d-48af-a650-bc2301651dea result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 08da9409-753a-47f6-b943-3eb2da2e5f43, 33078437-5ab2-47db-8711-876cffa90f94, f2b1405c-9823-481d-a5f1-9523a11a5dce, 6fea33c4-c1e6-4894-882d-67ab5486a325, 62b540c8-6950-43b3-a590-520b11bc8039 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, 121286d6-62fe-484f-8299-ffd8fd69ba14, fb9c38e8-5ae6-477a-ba7d-c9963e355902, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: f7843a45-1904-4d46-84c1-f7a99c2a0667, c870d944-a0e7-4780-b7d2-de9964a7e828, 2aea4ed2-7103-4b43-b845-7479023e7c3c, debd74ae-cf0e-4c43-8f81-8525a239a8aa, f0af8fdf-b92b-4604-bcc8-060168311300 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: f3ed2451-6e30-4324-8498-a6d856dec785, 49ee8cd6-647b-49c8-adf1-766644f99437, 0e365bcc-4492-4d7a-b413-87412097f819, fb062a09-219d-404b-a2a8-c3d0dd55cf64, d9e3f96c-9618-4a86-a8b6-e344225ea20e result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: , 074ec1a283f3b9da5a8ba50aae85c2a2, 3b6cd5d3ab0898cc8c05f17aaef5fbe0, 5d8f0ebb193f5718374ad92e5f0a51cb, 03af1e4995e2893c94946a30078953ae result, different first party: , 4528d4c2d5ec6fddf822a5c5a0604eae, 3108a523394736778fe5ada78ae286d4, ebd284890524d16f88fd8af7da70064a, 84c740f68d908a5654eadaa1cc17a84e unsupported: true, false, false, false, false passed: , true, true, true, true test failed: false, 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: , 40cf29c0378b52c38dfdd4763ba616a3, 5e11a5b200c3217edfa6ad322b1622e0, af500fa5b3e1c6857398056b460b81c0, 5bbe5cc4d51b5a1f052cbc8dfbb067a6 result, different first party: , e65ed2eb5be68fcec7040b6658f9b2eb, bac8f7d2c6bfa4de04a4bf88dad8270f, f1fc45f84fb4fd9bd5033e753b46a22e, fef116691b015150bb03b71487414689 unsupported: true, false, false, false, false passed: , true, true, true, true test failed: false, 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: , f67e2e8ccd8602e5cce7409ac3b930c3, 121a5382c2f40bfa01195a5112ad9bcf, d305ff9afc50cb52e0f5c04c153cd769, 450c7f6701acb17735d5c8a6d8066efc result, different first party: , 40db53fe87f2e80e35ac788d5dfcf488, a0f1e8ec41c18698cf6ae30eb67ac11a, eb6ba2655315491b3a08864b538107ed, 159f6a1ecbb18f3c958e0567fc0172f1 unsupported: true, false, false, false, false passed: , true, true, true, true test failed: false, 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: f518d7d19a1b7f2034e1c2459132d234, 07d11b04d9ee93de58c7847397e52115, 8860a30c24a545f559b1554dc14ddecc, 9b9004616239254ae7fa5c3f95bafd46, 094b6c9fbc58cccd03d7fe8055f09255 result, different first party: 4f11189a7889e88f6a831b2f07adc245, 56b404d35bdf3b539d2de8d4e6c88761, 03766d0b8991a3b6d548c5e22e4fed4b, 79e77c015396da104818f01ad80bb123, e70093e9502b543235518824a3d41c6b unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: , d0192d9a555cca7422a35798bff8afd4, 41aa6aa7b798fec5c098ff9a57eb7343, 50e4c8d52433195aaf9ad91af4970237, 844195c56726d16495acf71174703245 result, different first party: , 24354d9d925e3528f51e8c28142fb465, f29baaa962dd44e3b43418e24ce6ab9f, 7bd5ff592539bbb629429175dfacbc83, b1848c01e69692483368a8c455f08b3e unsupported: true, false, false, false, false passed: , true, true, true, true test failed: false, 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, true passed: undefined test failed: false, 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: , e2e1a58d6f7932f89b12ffe8e42a383b, 4ccf10dd3400fd7634cbdcc86264708a, 4ec0262e70e564368c09261586d8647c, ab4c4e7ea73ce430a894cbe6a5feb74f result, different first party: , 446289aa85ffd77b6165bd4c1f8642f0, 981db7f67ac9775a490aa4a6ef1afa1e, 10d892ba32f08ebcfefc86c285432a3a, a3c97983d8bdfdacab760c41f9dd7482 unsupported: true, false, false, false, false passed: , true, true, true, true test failed: false, 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: , a88791e1a0579c47f9bf7537abb693df, d154370595a70f135c4e4af1d20d3228, 0244af950bc8d89666ddb1fde71f63d4, df1fac48963628e9168f2d056ffa86ab result, different first party: , 562350bd6ee9f774fb85a4b88a7dff76, 82e08005fc400feaab2ea41ac3228f2f, a3bf4320cfe2d3dd0f860d7cb6e770dc, 444a5747a56f84d6c2c47d2a0d23c5fa unsupported: true, false, false, false, false passed: , true, true, true, true test failed: false, 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: , abb8819524faefcb5d836b7e88dc3b76, 1ec6c146468b7c1a46d81532cb893251, c7e3eb230da035e03ce867f205c83e35, 4b3f98d87c6abc6cbf56c63e6adbe9f8 result, different first party: , 0cbb7e9d861639af863f4af4b352ffdb, b3d5c727bfafaa76f1c45d1d547fe988, d32fe1b67f918bcdc6811388fb5fe01f, 1fd097cf1a4861e297c062ce77df9c64 unsupported: true, false, false, false, false passed: , true, true, true, true test failed: false, 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, true passed: undefined test failed: false, 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, not tested result, different first party: Used http, Used http, Used http, Used http, Used http unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http, Used http unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http, Used http unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http, Used http unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http, Used http unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http, Used http unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http, Used http unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http, Used http unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http, Used http unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested, not tested, not tested, not tested, not tested result, different first party: Used http, Used http, Used http, Used http, Used http unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
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, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
image 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: 2, 2, 2, 2, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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, 2 result, different first party: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
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: 9ac39a85-8ab7-4701-a180-e0258ffed06d, c8bec77d-63ba-4341-917e-b5408c92dcc5, 042d8f53-c559-43a6-a8a7-47ddc37130bd, 85f1f68b-7073-4597-b535-eb74b80aadd1, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 result, different first party: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701, d34c57c7-5d97-4e88-914b-e48338759e2a, f06fc2c4-1496-40d7-845d-8ece8392ef42, 61475483-e492-4381-8454-dd307e85da96, 52fa6d5a-aeff-4339-89d9-416078067571 result, different first party: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 622f476f-496f-479a-8210-d893d45008e3, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, 100e6983-45f4-461c-b471-82142ccb28cd, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e result, different first party: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 85251b22-cbd9-4601-86ba-3b4c577c26c1, 99137440-3c3f-4062-b7b6-b8b5656fe3e3, 326d2d25-8350-4dda-9fd0-47313dcd2617, e70d9262-de62-48cc-9f39-32381c778d9d, 31abe5a2-5672-4dbb-8117-f5bd46034efe result, different first party: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 4ba06d12-1bda-476e-9b5d-64a1e308d511, 3deec293-7da9-484f-9c66-ef3e09af2d78, d9848e10-1748-434d-bc7a-875a9ebb9509, 4452583e-047f-42e6-a3ed-e10ee6e982fe, 479d2517-702a-4d44-916c-2d5a02f1c810 result, different first party: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 5540e25b-012b-4070-9f09-14c82b3a2944, 93ebb577-e88b-4615-b2cc-ca6180e5fac5, 1b237b30-50d2-4301-912d-456f798b95b3, 3cd2a582-1831-4424-bfa6-c9d23d56df01, 52f72e7e-5a9d-48af-a650-bc2301651dea result, different first party: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 08da9409-753a-47f6-b943-3eb2da2e5f43, 33078437-5ab2-47db-8711-876cffa90f94, f2b1405c-9823-481d-a5f1-9523a11a5dce, 6fea33c4-c1e6-4894-882d-67ab5486a325, 62b540c8-6950-43b3-a590-520b11bc8039 result, different first party: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, 121286d6-62fe-484f-8299-ffd8fd69ba14, fb9c38e8-5ae6-477a-ba7d-c9963e355902, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea result, different first party: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: f7843a45-1904-4d46-84c1-f7a99c2a0667, c870d944-a0e7-4780-b7d2-de9964a7e828, 2aea4ed2-7103-4b43-b845-7479023e7c3c, debd74ae-cf0e-4c43-8f81-8525a239a8aa, f0af8fdf-b92b-4604-bcc8-060168311300 result, different first party: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: f3ed2451-6e30-4324-8498-a6d856dec785, 49ee8cd6-647b-49c8-adf1-766644f99437, 0e365bcc-4492-4d7a-b413-87412097f819, fb062a09-219d-404b-a2a8-c3d0dd55cf64, d9e3f96c-9618-4a86-a8b6-e344225ea20e result, different first party: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 9ac39a85-8ab7-4701-a180-e0258ffed06d, c8bec77d-63ba-4341-917e-b5408c92dcc5, 042d8f53-c559-43a6-a8a7-47ddc37130bd, 85f1f68b-7073-4597-b535-eb74b80aadd1, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: ecd8774e-b3ff-41e4-95e4-1f4d6a473701, d34c57c7-5d97-4e88-914b-e48338759e2a, f06fc2c4-1496-40d7-845d-8ece8392ef42, 61475483-e492-4381-8454-dd307e85da96, 52fa6d5a-aeff-4339-89d9-416078067571 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 622f476f-496f-479a-8210-d893d45008e3, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, 100e6983-45f4-461c-b471-82142ccb28cd, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 85251b22-cbd9-4601-86ba-3b4c577c26c1, 99137440-3c3f-4062-b7b6-b8b5656fe3e3, 326d2d25-8350-4dda-9fd0-47313dcd2617, e70d9262-de62-48cc-9f39-32381c778d9d, 31abe5a2-5672-4dbb-8117-f5bd46034efe result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 4ba06d12-1bda-476e-9b5d-64a1e308d511, 3deec293-7da9-484f-9c66-ef3e09af2d78, d9848e10-1748-434d-bc7a-875a9ebb9509, 4452583e-047f-42e6-a3ed-e10ee6e982fe, 479d2517-702a-4d44-916c-2d5a02f1c810 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 5540e25b-012b-4070-9f09-14c82b3a2944, 93ebb577-e88b-4615-b2cc-ca6180e5fac5, 1b237b30-50d2-4301-912d-456f798b95b3, 3cd2a582-1831-4424-bfa6-c9d23d56df01, 52f72e7e-5a9d-48af-a650-bc2301651dea result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 08da9409-753a-47f6-b943-3eb2da2e5f43, 33078437-5ab2-47db-8711-876cffa90f94, f2b1405c-9823-481d-a5f1-9523a11a5dce, 6fea33c4-c1e6-4894-882d-67ab5486a325, 62b540c8-6950-43b3-a590-520b11bc8039 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, 121286d6-62fe-484f-8299-ffd8fd69ba14, fb9c38e8-5ae6-477a-ba7d-c9963e355902, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: f7843a45-1904-4d46-84c1-f7a99c2a0667, c870d944-a0e7-4780-b7d2-de9964a7e828, 2aea4ed2-7103-4b43-b845-7479023e7c3c, debd74ae-cf0e-4c43-8f81-8525a239a8aa, f0af8fdf-b92b-4604-bcc8-060168311300 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: f3ed2451-6e30-4324-8498-a6d856dec785, 49ee8cd6-647b-49c8-adf1-766644f99437, 0e365bcc-4492-4d7a-b413-87412097f819, fb062a09-219d-404b-a2a8-c3d0dd55cf64, d9e3f96c-9618-4a86-a8b6-e344225ea20e result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 9ac39a85-8ab7-4701-a180-e0258ffed06d, c8bec77d-63ba-4341-917e-b5408c92dcc5, 042d8f53-c559-43a6-a8a7-47ddc37130bd, 85f1f68b-7073-4597-b535-eb74b80aadd1, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701, d34c57c7-5d97-4e88-914b-e48338759e2a, f06fc2c4-1496-40d7-845d-8ece8392ef42, 61475483-e492-4381-8454-dd307e85da96, 52fa6d5a-aeff-4339-89d9-416078067571 result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 622f476f-496f-479a-8210-d893d45008e3, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, 100e6983-45f4-461c-b471-82142ccb28cd, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 85251b22-cbd9-4601-86ba-3b4c577c26c1, 99137440-3c3f-4062-b7b6-b8b5656fe3e3, 326d2d25-8350-4dda-9fd0-47313dcd2617, e70d9262-de62-48cc-9f39-32381c778d9d, 31abe5a2-5672-4dbb-8117-f5bd46034efe result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 4ba06d12-1bda-476e-9b5d-64a1e308d511, 3deec293-7da9-484f-9c66-ef3e09af2d78, d9848e10-1748-434d-bc7a-875a9ebb9509, 4452583e-047f-42e6-a3ed-e10ee6e982fe, 479d2517-702a-4d44-916c-2d5a02f1c810 result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
  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: 08da9409-753a-47f6-b943-3eb2da2e5f43, 33078437-5ab2-47db-8711-876cffa90f94, f2b1405c-9823-481d-a5f1-9523a11a5dce, 6fea33c4-c1e6-4894-882d-67ab5486a325, 62b540c8-6950-43b3-a590-520b11bc8039 result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, 121286d6-62fe-484f-8299-ffd8fd69ba14, fb9c38e8-5ae6-477a-ba7d-c9963e355902, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: f7843a45-1904-4d46-84c1-f7a99c2a0667, c870d944-a0e7-4780-b7d2-de9964a7e828, 2aea4ed2-7103-4b43-b845-7479023e7c3c, debd74ae-cf0e-4c43-8f81-8525a239a8aa, f0af8fdf-b92b-4604-bcc8-060168311300 result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: f3ed2451-6e30-4324-8498-a6d856dec785, 49ee8cd6-647b-49c8-adf1-766644f99437, 0e365bcc-4492-4d7a-b413-87412097f819, fb062a09-219d-404b-a2a8-c3d0dd55cf64, d9e3f96c-9618-4a86-a8b6-e344225ea20e result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name'), Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different first party: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
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=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: , , , , result, different first party: , , , , unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${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: , , , , result, different first party: , , , , unsupported: false, false, false, false, false passed: undefined test failed: true, 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=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: , , , , result, different first party: , , , , unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${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: , , , , result, different first party: , , , , unsupported: false, false, false, false, false passed: undefined test failed: true, 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=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: , , , , result, different first party: , , , , unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${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: , , , , result, different first party: , , , , unsupported: false, false, false, false, false passed: undefined test failed: true, 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=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: , , , , result, different first party: , , , , unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${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: , , , , result, different first party: , , , , unsupported: false, false, false, false, false passed: undefined test failed: true, 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=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: , , , , result, different first party: , , , , unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${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: , , , , result, different first party: , , , , unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
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: 9ac39a85-8ab7-4701-a180-e0258ffed06d, c8bec77d-63ba-4341-917e-b5408c92dcc5, 042d8f53-c559-43a6-a8a7-47ddc37130bd, 85f1f68b-7073-4597-b535-eb74b80aadd1, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701, d34c57c7-5d97-4e88-914b-e48338759e2a, f06fc2c4-1496-40d7-845d-8ece8392ef42, 61475483-e492-4381-8454-dd307e85da96, 52fa6d5a-aeff-4339-89d9-416078067571 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: 622f476f-496f-479a-8210-d893d45008e3, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, 100e6983-45f4-461c-b471-82142ccb28cd, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: 85251b22-cbd9-4601-86ba-3b4c577c26c1, 99137440-3c3f-4062-b7b6-b8b5656fe3e3, 326d2d25-8350-4dda-9fd0-47313dcd2617, e70d9262-de62-48cc-9f39-32381c778d9d, 31abe5a2-5672-4dbb-8117-f5bd46034efe result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: 4ba06d12-1bda-476e-9b5d-64a1e308d511, 3deec293-7da9-484f-9c66-ef3e09af2d78, d9848e10-1748-434d-bc7a-875a9ebb9509, 4452583e-047f-42e6-a3ed-e10ee6e982fe, 479d2517-702a-4d44-916c-2d5a02f1c810 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
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, Error: Unsupported result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
  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: 08da9409-753a-47f6-b943-3eb2da2e5f43, 33078437-5ab2-47db-8711-876cffa90f94, f2b1405c-9823-481d-a5f1-9523a11a5dce, 6fea33c4-c1e6-4894-882d-67ab5486a325, 62b540c8-6950-43b3-a590-520b11bc8039 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, 121286d6-62fe-484f-8299-ffd8fd69ba14, fb9c38e8-5ae6-477a-ba7d-c9963e355902, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: f7843a45-1904-4d46-84c1-f7a99c2a0667, c870d944-a0e7-4780-b7d2-de9964a7e828, 2aea4ed2-7103-4b43-b845-7479023e7c3c, debd74ae-cf0e-4c43-8f81-8525a239a8aa, f0af8fdf-b92b-4604-bcc8-060168311300 result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  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: f3ed2451-6e30-4324-8498-a6d856dec785, 49ee8cd6-647b-49c8-adf1-766644f99437, 0e365bcc-4492-4d7a-b413-87412097f819, fb062a09-219d-404b-a2a8-c3d0dd55cf64, d9e3f96c-9618-4a86-a8b6-e344225ea20e result, different first party: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
TLS Session 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: 24985244c05ad4519f028a6107f044c83561c6b28e2d545d43fdf62a8f469897, 3ebcf5adb0cedf377091965ff0a5eb4c362617786f50c2b3cb2120a07e033c7c, 7514b0c42ada0a1b13a24132650e01cba907277856de9d70564b6baa2e615fb1, 8aab3ff84ff02baa2c98641c3cd8c78972a8abf912e881f1e09e665197e6419b, efa939855e90f6efc22ddbdfba3a140ba71a800cabece2cd083e657102b1fb3a result, different first party: c8045461cdb6b0843576023a75828d017da2ca796712a35623b4e927fb98c846, 335236b6148a351fcdeaaa3e9838063c4cff354da36a6649ba0160cc915913ec, b8f0676896cfc7a1c77d5ef5329e4fdfb5f4dc85cfe19d95e45f627261613820, e4c9726b64c07ca436345b97cdae7fe01a6ec8cb8d657a3c1fe9df5a708f474b, b10ad87255cc70c8e84da3b57ed2c037108e8b09f61155fb4d45a254486964a9 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: f7b90540ca666016486e30984dae0630dae0c0b173fb63709040941dc472986b, 345aa1f63fbf499efc0888bcd1c2d17b9eb20455969ecf176ed13bc2044abd56, 50ce9776b80c7356c6fad7aca54b2e5d54a834747bd7d9a8b41ae97da2e0578c, ca9d37d8077309f3bf60448af24b1db1ae0e1ae81c641e05970942ef606a249d, 9931292b5ce04b5d3e0e629715f465ef9b660895e33f487a92725bc45009a41e result, different first party: 8018b76d877e850ee00f34415395f651393b70093309f7fb70e08f403701f164, e38e8a3c78ad4281fe46723fc87a1f516f7696fdc64462fb440ae34ccbeb0ee8, 8ddbbf5d9c72d64779a90405f631a3915b28c1d9609ec65f304aa9202e994607, 67b03613d8d1f5726db5947b0c745e74290e6fb45aa0db1412013ea14b99efa5, 5b21caa16a366eff0afbcb387668c8ba4c0c97f8446a9921e6cd8ecb7eac9098 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 8bee7063589a07f1c027fd359694940a0bdd2d160e5b531e11aaab4a2abfb5be, d76456fce941f2e695e854c17545eb74dbdce66597e22e4009904dccc3a99a5a, 28f322b53b20fc384c102f62a3d151e0581745343af1faf59a04e430ca660bbb, 0b1b68055d3bf3412673478621a9c991663e7d3dbb78924fd210c0da0061ce4d, c23a7d232b67a9bb3885b0efbfcd4d5a1b9a8334db28a7c1e108a40568e1b247 result, different first party: aa20471584f744928b069d18084c4151a2658850276c2a0ef8054cfe50bcf61d, 3a5996e8b663ea295798e8587ac366b44c3d7d9b38904c9a8310b2a8509a265f, fd7e4baa062844433982bbce58dc74c35c1b32413919ee409e6ce8effb528bef, 0ae63fc2c5cfe533f2ec83fd96de75747657cb9b238df0943ca04750d963be57, 4c5fd579caa7bc353d046930e817abec51dd016a36f533ea11b55dec01c93ba9 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: e2fd394657a19fc5af120ad03f9e00f08fdab5b639760b106e24a0d8d8757b05, 4258d43f6be9443674864c1026e1d7335c5f6a4774db7c9fc5473ec130cf0e00, f3015d3e26a935dc75828cbdbe6fadd95e437296bb354a06314631f9d26af22f, 6152524856edfff158cfc6dbf9ee73e01ab201d16bf9f3ac36c36308952f2e96, 89acafdfa94b589a6000a6fa041f510249e113da71320a0e136c4b9eb057eaf5 result, different first party: 1658ed580696190b079839e364ea8ebc348162d0449cc76553d94b5fa04a9495, 2be56674660d2363213d4961d73faa5dfae793417fc67a64bfa2aa0e76059d53, aca0040627247679d7ac4247d354940a124cd1a897d66c8c8cb51fada2295d19, 65ff20d69fda87722a18e18d165a683eabcb609412562031b196afcc73b0f970, 89b3ba81b1744bcaaa0b9b5144238a8eb63e48ba52f10efc5bb5398e7232fb1f unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: d68ff8f1068bbccc4856cec9c0151d057e5af13453c9b50b218c7bc134013fce, 565721b1dd390b2ab25a3523682ef35833f18104711ca4d0a2ba55b911b2574e, cedeb2225ba26e18b22842438dff8e9a38f4b3376306542a70362ed58d43ea36, 16d419f461ced0a59163ec9c58cde3527ed6f8c1571a56c19b23febf03b12cf3, 25de83bdafccaea54d27a66459c52190ab3856e3111c51376df94713afc97371 result, different first party: 53d97eee1ddcb7f5f12c18d15bec9e72afba6059c5da47a6314a79b0d1ff9433, 06cba6ca00575a58adf50525e97448e750f911f90e9bfaa5abe80c7e8177b14e, bea4d6692bb07c29328b9113bebb54df7071b6fc13ecf7c8056967e3ec060c68, 265c72e377d3a81e80e4126292178c41832a19bcf2be4b26c7ea6aae93d035bf, 0a50576599d2d541afee1d9742a926445a830e91f5e1e5822b79d8d0cda16c66 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: e96d1ad3dd62f34be04066aa72b873eeeb4234300665c435796574abedaab950, 9767fda8af998d85a7a90b415278bf614ad661805b4b92b76e4de1e4df16630a, a7cb058236c126dc17a6b7e000b13443a75296b8416ea595888789e1f3348c84, 44ad537544f92857c2663202730f84752373ca164c61a227cc3c05f81eeb7839, 1826b5462e81cc5896cfa85f72e76fd04ad8236dbfb8e2bd62e89d0f137c81d1 result, different first party: a023663f13ec16b25ed7322f90e63a5e013abd1287c36095204f53fef35e158f, a7e7bc32cbf4b5798dddaabfc8c998408d3b426eade57cfb6445220c18842572, f14dcda69ce3f3ae2991b5dbe3bb1e01f2d144fe2d446359391cbde4abd7f864, 6670fa972318bd5ff1c42839a932cd16270d51e53303e9b98381f488609ea7cd, aac898e2cb6b7f635d4c5f1a1ff3ce57200f266adcaaa7c7610a0d0d8d59f877 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 97cd8260d37a8250f1a3c64788a0dd166a94c16bf82ab9314536aa09be49dd23, 7e49ec22ed8c59da4a091aa90f7ae4fd508127556645be67d9c437ebf7448e2d, 4fbef2b53f8fb211c78b3183230d0b975b143a507064d9f757501019aca307bd, 4366c400ebebc363a695713e6266b7595f956a3e2badeb60309e3e536385743e, a216094a33e7821355dbfb9462de8f636d39a6e1ca70baeec8041cf0e7e9bc4a result, different first party: 90437e9aadbe178e428c227b110763f520e8a3373f592cc361e10597a23ca1d2, a882edffb154a6434e8319dad93c4ddabfcb95732572d79fdde02b5faf29aba5, accaa4990c11aa3bc466d7b802b096debc2909e26c51dfc7236016ff6d7f9890, bfcd1f19a7e8a863b3d898df07e897b482c21c2e87502953d4d725f6520a5a43, ecf3703edbe015269a1304dc2ad64d1ba431a5f6a6104ef9ba6d266f7ad02493 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 2148eb57a004abc7794916874a67978e1e13396b059ce89583f2aa97878b72fd, ad2f1e2cbeca5bde40e7664cef53f37ca7111f38b8a41aea019260c792f08d84, f455a3331429ecc5868b021f273f4e95ffdcc10d40e7f1c77b1f24d1a65accd1, bc73ffec0d838c090145cd2a9e06f8bbede07a1cf5cc24b0e6794526e8b39c5b, d1d0d6c6851ceecf41880b9afbb7699dd8232ab526806d713ba329893f792277 result, different first party: c8047d5b5f18e7cdf72c7d87467d6f6b07f07beaf4cb87edb84bb93581b2be98, b97739459258dfff1ba80bf646ec817aac28d4279a11d448cf6e0b1cd2c5aa14, c72831abd4287f7232bee82d798e757999318e2d7edb524c4f35b4a1ef6c1448, 0a03b74bac97f5fc299b08e2e8aacb34e2fb8f50e7226e5d59253ff3e69f7d98, 8a8e22331227699635bca8e83b167ac23390c14b90ef522f4a51bcbc11672e80 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: ff89ed0a2165126a6271ce7f9520f1963f4e62aafeea064b91a7664a7f81e898, 5c809dffd64b9a01547d7843c3b39d5665cee0fb89199a24fd73b2cdda2ad8b6, 19b5b5c3a8b4ea531b9de181a4e23279134fd767ddcceb09c3ab11cfaad66927, 6f568e4c3ba339b37051fb5312e18b5d4c13ca03e2f7c2102b5ed468f381d4f9, 3b09570f4ea7c585b109995ada31c66338070ace940d80b6a0eee086effba86e result, different first party: 10accbb0424906de4ace8ca42b2cfa3c8e824e57242afd48b108fc675497596c, 54373041dbb71d82275e924d170d806005a52457f6d336ede6801633bd0ee50b, ad638567d4d02616318bbd082a50eba878087fc7fdef911f1b25202791a9c28b, d64f6b3d92d074a25eeb3263ad8b8ac291ac77aaacd806ac888c0cf32d6d2330, a5cbc1a4bf9eb8d960d4c5818c12e7a54d6bf6b29a633d38787445a70d185fec unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: a65332651028f5575e1fd4b72f11cbd1967414f93130e08591577e0fbf9d7b70, 942b7f18d07e8ec4390eea40e9343ed7b55d8e2ee428b3605d3542f2dc6a6542, 1f3a8835d9d190dcac4bcb9e64e8449fb7e859f5ae34a58028c1f93c20274356, 7e576ffce81c992f8f8cb5724e16ffade8a26aec921e4effb37758e2fac2df11, 036593405df339b0618fc5ecc625be1f3188f2d657b65bfa183158046eedf20d result, different first party: 9ce414ddb4e2afb94939878ca057a9ab0ae84736786a260bc471f8a1fdd6e9db, 5d6b45a088985a8bbb4632c4191475b4af665e523854023f49b69232d5287e94, 6318cf17040917b850c6dba8159a52729c8dc8cec0068dacfd9c549f51f8da47, 2155be94e4a7e2be6baef9780d4f37f1e3d6795c5d7539840053c9a1aa35eb55, d24aaff8893b21e23bf1c06047ede55543e6b3e434d9135465c7cb46a193e9e5 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: Error: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: false, false, false, false, false passed: undefined test failed: true, 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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: false, false, false, false, false passed: undefined test failed: true, 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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: false, false, false, false, false passed: undefined test failed: true, 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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: false, false, false, false, false passed: undefined test failed: true, 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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: false, false, false, false, false passed: undefined test failed: true, 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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: false, false, false, false, false passed: undefined test failed: true, 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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: false, false, false, false, false passed: undefined test failed: true, 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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: false, false, false, false, false passed: undefined test failed: true, 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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: false, false, false, false, false passed: undefined test failed: true, 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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: false, false, false, false, false passed: undefined test failed: true, true, true, true, true
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, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same first party: 1, 1, 1, 1, 1 result, different first party: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
Navigation 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/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/, https://test-pages.privacytests2.org/ unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
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: 9ac39a85-8ab7-4701-a180-e0258ffed06d, c8bec77d-63ba-4341-917e-b5408c92dcc5, 042d8f53-c559-43a6-a8a7-47ddc37130bd, 85f1f68b-7073-4597-b535-eb74b80aadd1, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: ecd8774e-b3ff-41e4-95e4-1f4d6a473701, d34c57c7-5d97-4e88-914b-e48338759e2a, f06fc2c4-1496-40d7-845d-8ece8392ef42, 61475483-e492-4381-8454-dd307e85da96, 52fa6d5a-aeff-4339-89d9-416078067571 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 622f476f-496f-479a-8210-d893d45008e3, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, 100e6983-45f4-461c-b471-82142ccb28cd, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 85251b22-cbd9-4601-86ba-3b4c577c26c1, 99137440-3c3f-4062-b7b6-b8b5656fe3e3, 326d2d25-8350-4dda-9fd0-47313dcd2617, e70d9262-de62-48cc-9f39-32381c778d9d, 31abe5a2-5672-4dbb-8117-f5bd46034efe result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 4ba06d12-1bda-476e-9b5d-64a1e308d511, 3deec293-7da9-484f-9c66-ef3e09af2d78, d9848e10-1748-434d-bc7a-875a9ebb9509, 4452583e-047f-42e6-a3ed-e10ee6e982fe, 479d2517-702a-4d44-916c-2d5a02f1c810 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 5540e25b-012b-4070-9f09-14c82b3a2944, 93ebb577-e88b-4615-b2cc-ca6180e5fac5, 1b237b30-50d2-4301-912d-456f798b95b3, 3cd2a582-1831-4424-bfa6-c9d23d56df01, 52f72e7e-5a9d-48af-a650-bc2301651dea result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 08da9409-753a-47f6-b943-3eb2da2e5f43, 33078437-5ab2-47db-8711-876cffa90f94, f2b1405c-9823-481d-a5f1-9523a11a5dce, 6fea33c4-c1e6-4894-882d-67ab5486a325, 62b540c8-6950-43b3-a590-520b11bc8039 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, 121286d6-62fe-484f-8299-ffd8fd69ba14, fb9c38e8-5ae6-477a-ba7d-c9963e355902, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: f7843a45-1904-4d46-84c1-f7a99c2a0667, c870d944-a0e7-4780-b7d2-de9964a7e828, 2aea4ed2-7103-4b43-b845-7479023e7c3c, debd74ae-cf0e-4c43-8f81-8525a239a8aa, f0af8fdf-b92b-4604-bcc8-060168311300 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: f3ed2451-6e30-4324-8498-a6d856dec785, 49ee8cd6-647b-49c8-adf1-766644f99437, 0e365bcc-4492-4d7a-b413-87412097f819, fb062a09-219d-404b-a2a8-c3d0dd55cf64, d9e3f96c-9618-4a86-a8b6-e344225ea20e result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_9ac39a85-8ab7-4701-a180-e0258ffed06d, name_c8bec77d-63ba-4341-917e-b5408c92dcc5, name_042d8f53-c559-43a6-a8a7-47ddc37130bd, name_85f1f68b-7073-4597-b535-eb74b80aadd1, name_36c60da1-6913-4c2a-a33f-4f6aaed4c1e3 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_ecd8774e-b3ff-41e4-95e4-1f4d6a473701, name_d34c57c7-5d97-4e88-914b-e48338759e2a, name_f06fc2c4-1496-40d7-845d-8ece8392ef42, name_61475483-e492-4381-8454-dd307e85da96, name_52fa6d5a-aeff-4339-89d9-416078067571 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_622f476f-496f-479a-8210-d893d45008e3, name_86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76, name_a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87, name_100e6983-45f4-461c-b471-82142ccb28cd, name_f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_85251b22-cbd9-4601-86ba-3b4c577c26c1, name_99137440-3c3f-4062-b7b6-b8b5656fe3e3, name_326d2d25-8350-4dda-9fd0-47313dcd2617, name_e70d9262-de62-48cc-9f39-32381c778d9d, name_31abe5a2-5672-4dbb-8117-f5bd46034efe result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_4ba06d12-1bda-476e-9b5d-64a1e308d511, name_3deec293-7da9-484f-9c66-ef3e09af2d78, name_d9848e10-1748-434d-bc7a-875a9ebb9509, name_4452583e-047f-42e6-a3ed-e10ee6e982fe, name_479d2517-702a-4d44-916c-2d5a02f1c810 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_5540e25b-012b-4070-9f09-14c82b3a2944, name_93ebb577-e88b-4615-b2cc-ca6180e5fac5, name_1b237b30-50d2-4301-912d-456f798b95b3, name_3cd2a582-1831-4424-bfa6-c9d23d56df01, name_52f72e7e-5a9d-48af-a650-bc2301651dea result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_08da9409-753a-47f6-b943-3eb2da2e5f43, name_33078437-5ab2-47db-8711-876cffa90f94, name_f2b1405c-9823-481d-a5f1-9523a11a5dce, name_6fea33c4-c1e6-4894-882d-67ab5486a325, name_62b540c8-6950-43b3-a590-520b11bc8039 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9, name_6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf, name_121286d6-62fe-484f-8299-ffd8fd69ba14, name_fb9c38e8-5ae6-477a-ba7d-c9963e355902, name_13cd54ac-fe53-46ba-8048-e7a79fcb47ea result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_f7843a45-1904-4d46-84c1-f7a99c2a0667, name_c870d944-a0e7-4780-b7d2-de9964a7e828, name_2aea4ed2-7103-4b43-b845-7479023e7c3c, name_debd74ae-cf0e-4c43-8f81-8525a239a8aa, name_f0af8fdf-b92b-4604-bcc8-060168311300 result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_f3ed2451-6e30-4324-8498-a6d856dec785, name_49ee8cd6-647b-49c8-adf1-766644f99437, name_0e365bcc-4492-4d7a-b413-87412097f819, name_fb062a09-219d-404b-a2a8-c3d0dd55cf64, name_d9e3f96c-9618-4a86-a8b6-e344225ea20e result, different first party: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false,false result: Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded,Insecure website loaded
  passed: false,false,false,false,false result: Insecure website loaded,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: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,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: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,false,false,false,false
  upgraded: false,false,false,false,false passed: false,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: false,false,false,false,false result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
  passed: true,true,true,true,true result: upgraded,upgraded,upgraded,upgraded,upgraded
  passed: false,false,false,false,false result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
  passed: true,true,true,true,true result: upgraded,upgraded,upgraded,upgraded,upgraded
  passed: false,false,false,false,false result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
  passed: false,false,false,false,false result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
  passed: false,false,false,false,false result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
  passed: false,false,false,false,false result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
  passed: true,true,true,true,true result: upgraded,upgraded,upgraded,upgraded,upgraded
  passed: false,false,false,false,false result: loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely,loaded insecurely
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,true result: blocked,blocked,blocked,blocked,blocked
  passed: true,true,true,true,true result: blocked,blocked,blocked,blocked,blocked
  passed: true,true,true,true,true result: blocked,blocked,blocked,blocked,blocked
  passed: true,true,true,true,true result: blocked,blocked,blocked,blocked,blocked
  passed: true,true,true,true,true result: blocked,blocked,blocked,blocked,blocked
  passed: true,true,true,true,true result: blocked,blocked,blocked,blocked,blocked
  passed: true,true,true,true,true result: blocked,blocked,blocked,blocked,blocked
  passed: true,true,true,true,true result: blocked,blocked,blocked,blocked,blocked
  passed: true,true,true,true,true result: blocked,blocked,blocked,blocked,blocked
  passed: true,true,true,true,true result: blocked,blocked,blocked,blocked,blocked
Misc tests Which browsers provide additional assorted privacy protections?
This category includes tests for the presence of miscellaneous privacy features
ECH enabledEncrypted Client Hello (ECH) is a new protocol that hides the website you are visiting from third-party network eavesdroppers.
  SNI_status: plaintext passed: false,false,false,false,false
  SNI_status: plaintext passed: false,false,false,false,false
  SNI_status: plaintext passed: false,false,false,false,false
  SNI_status: plaintext passed: false,false,false,false,false
  SNI_status: plaintext passed: false,false,false,false,false
  SNI_status: plaintext passed: false,false,false,false,false
  SNI_status: plaintext passed: false,false,false,false,false
  SNI_status: plaintext passed: false,false,false,false,false
  SNI_status: plaintext passed: false,false,false,false,false
  SNI_status: plaintext passed: false,false,false,false,false
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: undefined passed: false,false,false,false,false
  header value: undefined passed: false,false,false,false,false
  header value: undefined passed: false,false,false,false,false
  header value: undefined passed: false,false,false,false,false
  header value: undefined passed: false,false,false,false,false
  header value: undefined passed: false,false,false,false,false
  header value: undefined passed: false,false,false,false,false
  header value: undefined passed: false,false,false,false,false
  header value: undefined passed: false,false,false,false,false
  header value: undefined passed: false,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.
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,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,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,false,false,false,false
  passed: false,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,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false,false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true,true,true,true,true readSameFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported readDifferentFirstParty: Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported,Error: Unsupported testFailed: false,false,false,false,false
Tor 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,false passed: false,false,false,false,false
  IsTorExit: false,false,false,false,false passed: false,false,false,false,false
  IsTorExit: false,false,false,false,false passed: false,false,false,false,false
  IsTorExit: false,false,false,false,false passed: false,false,false,false,false
  IsTorExit: false,false,false,false,false passed: false,false,false,false,false
  IsTorExit: false,false,false,false,false passed: false,false,false,false,false
  IsTorExit: false,false,false,false,false passed: false,false,false,false,false
  IsTorExit: false,false,false,false,false passed: false,false,false,false,false
  IsTorExit: false,false,false,false,false passed: false,false,false,false,false
  IsTorExit: false,false,false,false,false passed: false,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: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
Media query screen widthWidth of the user's screen in pixels.
  expression: undefined desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: undefined desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
outerHeightHeight of the browser window in pixels, including browser chrome.
  expression: outerHeight desired expression: undefined actual value: 553,553,553,553,553 desired value: undefined passed: false,false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 546,546,546,546,546 desired value: undefined passed: false,false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 561,561,561,561,561 desired value: undefined passed: false,false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 547,547,547,547,547 desired value: undefined passed: false,false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 547,547,547,547,547 desired value: undefined passed: false,false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 555,555,555,555,555 desired value: undefined passed: false,false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 508,508,508,508,508 desired value: undefined passed: false,false,false,false,false
  expression: outerHeight desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
screen.heightHeight of the user's screen, in pixels.
  expression: screen.height desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: screen.height desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: screen.height desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: screen.height desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: screen.height desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: screen.height desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: screen.height desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: screen.height desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: screen.height desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
  expression: screen.height desired expression: undefined actual value: 667,667,667,667,667 desired value: undefined passed: false,false,false,false,false
screen.widthWidth of the user's screen, in pixels.
  expression: screen.width desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: screen.width desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: screen.width desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: screen.width desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: screen.width desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: screen.width desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: screen.width desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: screen.width desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: screen.width desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
  expression: screen.width desired expression: undefined actual value: 375,375,375,375,375 desired value: undefined passed: false,false,false,false,false
screenXPosition, in pixels, of the left edge of the browser window on screen.
  expression: screenX desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenX desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
screenYPosition, in pixels, of the top edge of the browser window on screen.
  expression: screenY desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenY desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenY desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenY desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenY desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenY desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenY desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenY desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenY desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
  expression: screenY desired expression: undefined actual value: 0,0,0,0,0 desired value: undefined passed: true,true,true,true,true
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,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
__hsscHubSpot tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
__hstcHubSpot tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
__sDrip.com email address tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
_hsencHubSpot tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
_openstatYandex tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
dclidDoubleClick Click ID (Google)
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
fbclidFacebook Click Identifier
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
gclidGoogle Click Identifier
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
hsCtaTrackingHubSpot tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
mc_eidMailchimp Email ID (email recipient's address)
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
mkt_tokAdobe Marketo tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
ml_subscriberMailerLite email tracking
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
ml_subscriber_hashMailerLite email tracking
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
msclkidMicrosoft Click ID
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
oly_anon_idOmeda marketing 'anonymous' customer id
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
oly_enc_idOmeda marketing 'known' customer id
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
rb_clickidUnknown high-entropy tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
s_cidAdobe Site Catalyst tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
vero_convVero tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
vero_idVero tracking parameter
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
wickedidWicked Reports e-commerce tracking
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
yclidYandex Click ID
  passed: true,true,true,true,true
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,false,false,false,false
  value: 8067384217479254 passed: false,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,true
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: true,true,true,true,true
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: true,true,true,true,true
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: false,false,false,false,false
  url: https://munchkin.marketo.net/munchkin.js passed: false,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,true
  url: https://dpm.demdex.net/ibs passed: false,false,false,false,false
  url: https://dpm.demdex.net/ibs passed: true,true,true,true,true
  url: https://dpm.demdex.net/ibs passed: false,false,false,false,false
  url: https://dpm.demdex.net/ibs passed: false,false,false,false,false
  url: https://dpm.demdex.net/ibs passed: true,true,true,true,true
  url: https://dpm.demdex.net/ibs passed: false,false,false,false,false
  url: https://dpm.demdex.net/ibs passed: false,false,false,false,false
  url: https://dpm.demdex.net/ibs passed: false,false,false,false,false
  url: https://dpm.demdex.net/ibs passed: false,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,true
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: true,true,true,true,true
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: true,true,true,true,true
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: false,false,false,false,false
  url: https://s.amazon-adsystem.com/dcm passed: false,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,true
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: true,true,true,true,true
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: true,true,true,true,true
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,false,false,false,false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false,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,true
  url: https://bat.bing.com/bat.js passed: false,false,false,false,false
  url: https://bat.bing.com/bat.js passed: true,true,true,true,true
  url: https://bat.bing.com/bat.js passed: false,false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,false,false,false,false
  url: https://bat.bing.com/bat.js passed: false,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,true
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: true,true,true,true,true
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: true,true,true,true,true
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,false,false,false,false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false,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,true
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: true,true,true,true,true
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: true,true,true,true,true
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false,false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false,false,false,false,false
DoubleClick (Google)Tests whether the browser blocks the page from loading the tracker at https://securepubads.g.doubleclick.net/static/glade.js
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: true,true,true,true,true
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: true,true,true,true,true
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: true,true,true,true,true
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,false,false,false,false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false,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,true
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: true,true,true,true,true
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: true,true,true,true,true
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false,false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false,false,false,false,false
Google (third-party ad pixel)Tests whether the browser blocks the page from loading the tracker at https://www.google.com/pagead/1p-user-list/
  url: https://www.google.com/pagead/1p-user-list/ passed: true,true,true,true,true
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: true,true,true,true,true
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,false,false,false,false
  url: https://www.google.com/pagead/1p-user-list/ passed: false,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,true
  url: https://google-analytics.com/urchin.js passed: false,false,false,false,false
  url: https://google-analytics.com/urchin.js passed: true,true,true,true,true
  url: https://google-analytics.com/urchin.js passed: false,false,false,false,false
  url: https://google-analytics.com/urchin.js passed: false,false,false,false,false
  url: https://google-analytics.com/urchin.js passed: true,true,true,true,true
  url: https://google-analytics.com/urchin.js passed: false,false,false,false,false
  url: https://google-analytics.com/urchin.js passed: false,false,false,false,false
  url: https://google-analytics.com/urchin.js passed: false,false,false,false,false
  url: https://google-analytics.com/urchin.js passed: false,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,true
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: true,true,true,true,true
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,false,false,false,false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false,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,true
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,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,true
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,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,false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: true,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,false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,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,false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false,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,true
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: true,true,true,true,true
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: true,true,true,true,true
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,false,false,false,false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false,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,true
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: true,true,true,true,true
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: true,true,true,true,true
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: false,false,false,false,false
  url: https://pixel.quantserve.com/pixel passed: false,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,true
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: true,true,true,true,true
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: true,true,true,true,true
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,false,false,false,false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false,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,true
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: true,true,true,true,true
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: true,true,true,true,true
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,false,false,false,false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false,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,true
  url: https://t.co/i/adsct passed: false,false,false,false,false
  url: https://t.co/i/adsct passed: true,true,true,true,true
  url: https://t.co/i/adsct passed: false,false,false,false,false
  url: https://t.co/i/adsct passed: false,false,false,false,false
  url: https://t.co/i/adsct passed: false,false,false,false,false
  url: https://t.co/i/adsct passed: false,false,false,false,false
  url: https://t.co/i/adsct passed: false,false,false,false,false
  url: https://t.co/i/adsct passed: false,false,false,false,false
  url: https://t.co/i/adsct passed: false,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,true
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: true,true,true,true,true
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,false,false,false,false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false,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: h2, h3, h2, h3, h2 result, different session: h3, h2, h3, h2, h3 unsupported: true, false, true, false, true passed: , true, true test failed: false, 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, h3, h2, h3, h2 result, different session: h3, h2, h3, h2, h3 unsupported: true, false, true, false, true passed: , true, true test failed: false, 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, h3, h2, h3, h2 result, different session: h2, h2, h3, h2, h3 unsupported: true, false, true, false, true passed: , true, true test failed: false, 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, h2, h3, h2, h3 result, different session: h2, h3, h2, h3, h2 unsupported: false, true, false, true, false passed: true, true, true test failed: false, 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, h3, h2, h3, h2 result, different session: h3, h2, h3, h2, h3 unsupported: true, false, true, false, true passed: , true, true test failed: false, 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, h2 result, different session: h2, h2, h2, h2, h2 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, h3, h2, h3, h2 result, different session: h3, h2, h3, h2, h3 unsupported: true, false, true, false, true passed: , true, true test failed: false, 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, h3, h2, h3, h2 result, different session: h3, h2, h3, h2, h3 unsupported: true, false, true, false, true passed: , true, true test failed: false, 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, h3, h2, h3, h2 result, different session: h3, h2, h3, h2, h3 unsupported: true, false, true, false, true passed: , true, true test failed: false, 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, h2 result, different session: h2, h2, h2, h2, h2 unsupported: true, true, true, true, true passed: undefined test failed: false, 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=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: e917fd3f-2558-42ac-b08f-c6cd639cb554_1p, e917fd3f-2558-42ac-b08f-c6cd639cb554_1p, e917fd3f-2558-42ac-b08f-c6cd639cb554_1p, e917fd3f-2558-42ac-b08f-c6cd639cb554_1p, e917fd3f-2558-42ac-b08f-c6cd639cb554_1p result, different session: e917fd3f-2558-42ac-b08f-c6cd639cb554_1p, e917fd3f-2558-42ac-b08f-c6cd639cb554_1p, e917fd3f-2558-42ac-b08f-c6cd639cb554_1p, e917fd3f-2558-42ac-b08f-c6cd639cb554_1p, e917fd3f-2558-42ac-b08f-c6cd639cb554_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: a715dfe4-a7ff-4477-929c-50938cc67332_1p, a715dfe4-a7ff-4477-929c-50938cc67332_1p, a715dfe4-a7ff-4477-929c-50938cc67332_1p, a715dfe4-a7ff-4477-929c-50938cc67332_1p, a715dfe4-a7ff-4477-929c-50938cc67332_1p result, different session: a715dfe4-a7ff-4477-929c-50938cc67332_1p, a715dfe4-a7ff-4477-929c-50938cc67332_1p, a715dfe4-a7ff-4477-929c-50938cc67332_1p, a715dfe4-a7ff-4477-929c-50938cc67332_1p, a715dfe4-a7ff-4477-929c-50938cc67332_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: fcb49e69-7fe4-48a9-88b1-353f709309bc_1p, fcb49e69-7fe4-48a9-88b1-353f709309bc_1p, fcb49e69-7fe4-48a9-88b1-353f709309bc_1p, fcb49e69-7fe4-48a9-88b1-353f709309bc_1p, fcb49e69-7fe4-48a9-88b1-353f709309bc_1p result, different session: fcb49e69-7fe4-48a9-88b1-353f709309bc_1p, fcb49e69-7fe4-48a9-88b1-353f709309bc_1p, fcb49e69-7fe4-48a9-88b1-353f709309bc_1p, fcb49e69-7fe4-48a9-88b1-353f709309bc_1p, fcb49e69-7fe4-48a9-88b1-353f709309bc_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_1p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_1p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_1p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_1p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_1p result, different session: 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_1p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_1p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_1p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_1p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: 79784830-014a-400f-b0f9-624dcd93d540_1p, 79784830-014a-400f-b0f9-624dcd93d540_1p, 79784830-014a-400f-b0f9-624dcd93d540_1p, 79784830-014a-400f-b0f9-624dcd93d540_1p, 79784830-014a-400f-b0f9-624dcd93d540_1p result, different session: 79784830-014a-400f-b0f9-624dcd93d540_1p, 79784830-014a-400f-b0f9-624dcd93d540_1p, 79784830-014a-400f-b0f9-624dcd93d540_1p, 79784830-014a-400f-b0f9-624dcd93d540_1p, 79784830-014a-400f-b0f9-624dcd93d540_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') result, different session: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: f6eca5e9-57f3-489d-8966-88072f14efaf_1p, f6eca5e9-57f3-489d-8966-88072f14efaf_1p, f6eca5e9-57f3-489d-8966-88072f14efaf_1p, f6eca5e9-57f3-489d-8966-88072f14efaf_1p, f6eca5e9-57f3-489d-8966-88072f14efaf_1p result, different session: f6eca5e9-57f3-489d-8966-88072f14efaf_1p, f6eca5e9-57f3-489d-8966-88072f14efaf_1p, f6eca5e9-57f3-489d-8966-88072f14efaf_1p, f6eca5e9-57f3-489d-8966-88072f14efaf_1p, f6eca5e9-57f3-489d-8966-88072f14efaf_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: 4e05b678-bc4e-4360-baca-31ef3e710454_1p, 4e05b678-bc4e-4360-baca-31ef3e710454_1p, 4e05b678-bc4e-4360-baca-31ef3e710454_1p, 4e05b678-bc4e-4360-baca-31ef3e710454_1p, 4e05b678-bc4e-4360-baca-31ef3e710454_1p result, different session: 4e05b678-bc4e-4360-baca-31ef3e710454_1p, 4e05b678-bc4e-4360-baca-31ef3e710454_1p, 4e05b678-bc4e-4360-baca-31ef3e710454_1p, 4e05b678-bc4e-4360-baca-31ef3e710454_1p, 4e05b678-bc4e-4360-baca-31ef3e710454_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: f94a2bed-b91e-44c0-a465-b0ab4050575c_1p, f94a2bed-b91e-44c0-a465-b0ab4050575c_1p, f94a2bed-b91e-44c0-a465-b0ab4050575c_1p, f94a2bed-b91e-44c0-a465-b0ab4050575c_1p, f94a2bed-b91e-44c0-a465-b0ab4050575c_1p result, different session: f94a2bed-b91e-44c0-a465-b0ab4050575c_1p, f94a2bed-b91e-44c0-a465-b0ab4050575c_1p, f94a2bed-b91e-44c0-a465-b0ab4050575c_1p, f94a2bed-b91e-44c0-a465-b0ab4050575c_1p, f94a2bed-b91e-44c0-a465-b0ab4050575c_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: 463b4922-4edb-4a1a-a19b-d9f63985520d_1p, 463b4922-4edb-4a1a-a19b-d9f63985520d_1p, 463b4922-4edb-4a1a-a19b-d9f63985520d_1p, 463b4922-4edb-4a1a-a19b-d9f63985520d_1p, 463b4922-4edb-4a1a-a19b-d9f63985520d_1p result, different session: 463b4922-4edb-4a1a-a19b-d9f63985520d_1p, 463b4922-4edb-4a1a-a19b-d9f63985520d_1p, 463b4922-4edb-4a1a-a19b-d9f63985520d_1p, 463b4922-4edb-4a1a-a19b-d9f63985520d_1p, 463b4922-4edb-4a1a-a19b-d9f63985520d_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
cookie (HTTP)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
  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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 9ac39a85-8ab7-4701-a180-e0258ffed06d_1p_http, c8bec77d-63ba-4341-917e-b5408c92dcc5_1p_http, 042d8f53-c559-43a6-a8a7-47ddc37130bd_1p_http, 85f1f68b-7073-4597-b535-eb74b80aadd1_1p_http, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_1p_http result, different session: 9ac39a85-8ab7-4701-a180-e0258ffed06d_1p_http, c8bec77d-63ba-4341-917e-b5408c92dcc5_1p_http, 042d8f53-c559-43a6-a8a7-47ddc37130bd_1p_http, 85f1f68b-7073-4597-b535-eb74b80aadd1_1p_http, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_1p_http unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_1p_http, d34c57c7-5d97-4e88-914b-e48338759e2a_1p_http, f06fc2c4-1496-40d7-845d-8ece8392ef42_1p_http, 61475483-e492-4381-8454-dd307e85da96_1p_http, 52fa6d5a-aeff-4339-89d9-416078067571_1p_http result, different session: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_1p_http, d34c57c7-5d97-4e88-914b-e48338759e2a_1p_http, f06fc2c4-1496-40d7-845d-8ece8392ef42_1p_http, 61475483-e492-4381-8454-dd307e85da96_1p_http, 52fa6d5a-aeff-4339-89d9-416078067571_1p_http unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 622f476f-496f-479a-8210-d893d45008e3_1p_http, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_1p_http, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_1p_http, 100e6983-45f4-461c-b471-82142ccb28cd_1p_http, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_1p_http result, different session: 622f476f-496f-479a-8210-d893d45008e3_1p_http, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_1p_http, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_1p_http, 100e6983-45f4-461c-b471-82142ccb28cd_1p_http, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_1p_http unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: 85251b22-cbd9-4601-86ba-3b4c577c26c1_1p_http, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_1p_http, 326d2d25-8350-4dda-9fd0-47313dcd2617_1p_http, e70d9262-de62-48cc-9f39-32381c778d9d_1p_http, 31abe5a2-5672-4dbb-8117-f5bd46034efe_1p_http result, different session: 85251b22-cbd9-4601-86ba-3b4c577c26c1_1p_http, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_1p_http, 326d2d25-8350-4dda-9fd0-47313dcd2617_1p_http, e70d9262-de62-48cc-9f39-32381c778d9d_1p_http, 31abe5a2-5672-4dbb-8117-f5bd46034efe_1p_http unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 4ba06d12-1bda-476e-9b5d-64a1e308d511_1p_http, 3deec293-7da9-484f-9c66-ef3e09af2d78_1p_http, d9848e10-1748-434d-bc7a-875a9ebb9509_1p_http, 4452583e-047f-42e6-a3ed-e10ee6e982fe_1p_http, 479d2517-702a-4d44-916c-2d5a02f1c810_1p_http result, different session: 4ba06d12-1bda-476e-9b5d-64a1e308d511_1p_http, 3deec293-7da9-484f-9c66-ef3e09af2d78_1p_http, d9848e10-1748-434d-bc7a-875a9ebb9509_1p_http, 4452583e-047f-42e6-a3ed-e10ee6e982fe_1p_http, 479d2517-702a-4d44-916c-2d5a02f1c810_1p_http unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: 5540e25b-012b-4070-9f09-14c82b3a2944_1p_http, 93ebb577-e88b-4615-b2cc-ca6180e5fac5_1p_http, 1b237b30-50d2-4301-912d-456f798b95b3_1p_http, 3cd2a582-1831-4424-bfa6-c9d23d56df01_1p_http, 52f72e7e-5a9d-48af-a650-bc2301651dea_1p_http result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: 08da9409-753a-47f6-b943-3eb2da2e5f43_1p_http, 33078437-5ab2-47db-8711-876cffa90f94_1p_http, f2b1405c-9823-481d-a5f1-9523a11a5dce_1p_http, 6fea33c4-c1e6-4894-882d-67ab5486a325_1p_http, 62b540c8-6950-43b3-a590-520b11bc8039_1p_http result, different session: 08da9409-753a-47f6-b943-3eb2da2e5f43_1p_http, 33078437-5ab2-47db-8711-876cffa90f94_1p_http, f2b1405c-9823-481d-a5f1-9523a11a5dce_1p_http, 6fea33c4-c1e6-4894-882d-67ab5486a325_1p_http, 62b540c8-6950-43b3-a590-520b11bc8039_1p_http unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_1p_http, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_1p_http, 121286d6-62fe-484f-8299-ffd8fd69ba14_1p_http, fb9c38e8-5ae6-477a-ba7d-c9963e355902_1p_http, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_1p_http result, different session: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_1p_http, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_1p_http, 121286d6-62fe-484f-8299-ffd8fd69ba14_1p_http, fb9c38e8-5ae6-477a-ba7d-c9963e355902_1p_http, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_1p_http unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: f7843a45-1904-4d46-84c1-f7a99c2a0667_1p_http, c870d944-a0e7-4780-b7d2-de9964a7e828_1p_http, 2aea4ed2-7103-4b43-b845-7479023e7c3c_1p_http, debd74ae-cf0e-4c43-8f81-8525a239a8aa_1p_http, f0af8fdf-b92b-4604-bcc8-060168311300_1p_http result, different session: f7843a45-1904-4d46-84c1-f7a99c2a0667_1p_http, c870d944-a0e7-4780-b7d2-de9964a7e828_1p_http, 2aea4ed2-7103-4b43-b845-7479023e7c3c_1p_http, debd74ae-cf0e-4c43-8f81-8525a239a8aa_1p_http, f0af8fdf-b92b-4604-bcc8-060168311300_1p_http unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: f3ed2451-6e30-4324-8498-a6d856dec785_1p_http, 49ee8cd6-647b-49c8-adf1-766644f99437_1p_http, 0e365bcc-4492-4d7a-b413-87412097f819_1p_http, fb062a09-219d-404b-a2a8-c3d0dd55cf64_1p_http, d9e3f96c-9618-4a86-a8b6-e344225ea20e_1p_http result, different session: f3ed2451-6e30-4324-8498-a6d856dec785_1p_http, 49ee8cd6-647b-49c8-adf1-766644f99437_1p_http, 0e365bcc-4492-4d7a-b413-87412097f819_1p_http, fb062a09-219d-404b-a2a8-c3d0dd55cf64_1p_http, d9e3f96c-9618-4a86-a8b6-e344225ea20e_1p_http unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
cookie (JS)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 9ac39a85-8ab7-4701-a180-e0258ffed06d_1p_js, c8bec77d-63ba-4341-917e-b5408c92dcc5_1p_js, 042d8f53-c559-43a6-a8a7-47ddc37130bd_1p_js, 85f1f68b-7073-4597-b535-eb74b80aadd1_1p_js, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_1p_js result, different session: 9ac39a85-8ab7-4701-a180-e0258ffed06d_1p_js, c8bec77d-63ba-4341-917e-b5408c92dcc5_1p_js, 042d8f53-c559-43a6-a8a7-47ddc37130bd_1p_js, 85f1f68b-7073-4597-b535-eb74b80aadd1_1p_js, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_1p_js unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_1p_js, d34c57c7-5d97-4e88-914b-e48338759e2a_1p_js, f06fc2c4-1496-40d7-845d-8ece8392ef42_1p_js, 61475483-e492-4381-8454-dd307e85da96_1p_js, 52fa6d5a-aeff-4339-89d9-416078067571_1p_js result, different session: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_1p_js, d34c57c7-5d97-4e88-914b-e48338759e2a_1p_js, f06fc2c4-1496-40d7-845d-8ece8392ef42_1p_js, 61475483-e492-4381-8454-dd307e85da96_1p_js, 52fa6d5a-aeff-4339-89d9-416078067571_1p_js unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 622f476f-496f-479a-8210-d893d45008e3_1p_js, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_1p_js, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_1p_js, 100e6983-45f4-461c-b471-82142ccb28cd_1p_js, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_1p_js result, different session: 622f476f-496f-479a-8210-d893d45008e3_1p_js, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_1p_js, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_1p_js, 100e6983-45f4-461c-b471-82142ccb28cd_1p_js, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_1p_js unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 85251b22-cbd9-4601-86ba-3b4c577c26c1_1p_js, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_1p_js, 326d2d25-8350-4dda-9fd0-47313dcd2617_1p_js, e70d9262-de62-48cc-9f39-32381c778d9d_1p_js, 31abe5a2-5672-4dbb-8117-f5bd46034efe_1p_js result, different session: 85251b22-cbd9-4601-86ba-3b4c577c26c1_1p_js, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_1p_js, 326d2d25-8350-4dda-9fd0-47313dcd2617_1p_js, e70d9262-de62-48cc-9f39-32381c778d9d_1p_js, 31abe5a2-5672-4dbb-8117-f5bd46034efe_1p_js unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 4ba06d12-1bda-476e-9b5d-64a1e308d511_1p_js, 3deec293-7da9-484f-9c66-ef3e09af2d78_1p_js, d9848e10-1748-434d-bc7a-875a9ebb9509_1p_js, 4452583e-047f-42e6-a3ed-e10ee6e982fe_1p_js, 479d2517-702a-4d44-916c-2d5a02f1c810_1p_js result, different session: 4ba06d12-1bda-476e-9b5d-64a1e308d511_1p_js, 3deec293-7da9-484f-9c66-ef3e09af2d78_1p_js, d9848e10-1748-434d-bc7a-875a9ebb9509_1p_js, 4452583e-047f-42e6-a3ed-e10ee6e982fe_1p_js, 479d2517-702a-4d44-916c-2d5a02f1c810_1p_js unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 5540e25b-012b-4070-9f09-14c82b3a2944_1p_js, 93ebb577-e88b-4615-b2cc-ca6180e5fac5_1p_js, 1b237b30-50d2-4301-912d-456f798b95b3_1p_js, 3cd2a582-1831-4424-bfa6-c9d23d56df01_1p_js, 52f72e7e-5a9d-48af-a650-bc2301651dea_1p_js result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: 08da9409-753a-47f6-b943-3eb2da2e5f43_1p_js, 33078437-5ab2-47db-8711-876cffa90f94_1p_js, f2b1405c-9823-481d-a5f1-9523a11a5dce_1p_js, 6fea33c4-c1e6-4894-882d-67ab5486a325_1p_js, 62b540c8-6950-43b3-a590-520b11bc8039_1p_js result, different session: 08da9409-753a-47f6-b943-3eb2da2e5f43_1p_js, 33078437-5ab2-47db-8711-876cffa90f94_1p_js, f2b1405c-9823-481d-a5f1-9523a11a5dce_1p_js, 6fea33c4-c1e6-4894-882d-67ab5486a325_1p_js, 62b540c8-6950-43b3-a590-520b11bc8039_1p_js unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_1p_js, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_1p_js, 121286d6-62fe-484f-8299-ffd8fd69ba14_1p_js, fb9c38e8-5ae6-477a-ba7d-c9963e355902_1p_js, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_1p_js result, different session: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_1p_js, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_1p_js, 121286d6-62fe-484f-8299-ffd8fd69ba14_1p_js, fb9c38e8-5ae6-477a-ba7d-c9963e355902_1p_js, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_1p_js unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: f7843a45-1904-4d46-84c1-f7a99c2a0667_1p_js, c870d944-a0e7-4780-b7d2-de9964a7e828_1p_js, 2aea4ed2-7103-4b43-b845-7479023e7c3c_1p_js, debd74ae-cf0e-4c43-8f81-8525a239a8aa_1p_js, f0af8fdf-b92b-4604-bcc8-060168311300_1p_js result, different session: f7843a45-1904-4d46-84c1-f7a99c2a0667_1p_js, c870d944-a0e7-4780-b7d2-de9964a7e828_1p_js, 2aea4ed2-7103-4b43-b845-7479023e7c3c_1p_js, debd74ae-cf0e-4c43-8f81-8525a239a8aa_1p_js, f0af8fdf-b92b-4604-bcc8-060168311300_1p_js unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: f3ed2451-6e30-4324-8498-a6d856dec785_1p_js, 49ee8cd6-647b-49c8-adf1-766644f99437_1p_js, 0e365bcc-4492-4d7a-b413-87412097f819_1p_js, fb062a09-219d-404b-a2a8-c3d0dd55cf64_1p_js, d9e3f96c-9618-4a86-a8b6-e344225ea20e_1p_js result, different session: f3ed2451-6e30-4324-8498-a6d856dec785_1p_js, 49ee8cd6-647b-49c8-adf1-766644f99437_1p_js, 0e365bcc-4492-4d7a-b413-87412097f819_1p_js, fb062a09-219d-404b-a2a8-c3d0dd55cf64_1p_js, d9e3f96c-9618-4a86-a8b6-e344225ea20e_1p_js unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
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_377115615293796, fake_5240120155630232, fake_38831693293000336, fake_5148599980442992, fake_33427972900051794 result, different session: fake_377115615293796, fake_5240120155630232, fake_38831693293000336, fake_5148599980442992, fake_33427972900051794 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_025349500715979856, fake_5117419577540945, fake_48572638077527364, fake_015070290709322531, fake_6905150319494875 result, different session: fake_025349500715979856, fake_5117419577540945, fake_48572638077527364, fake_015070290709322531, fake_6905150319494875 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_8247675995424364, fake_3623040345849331, fake_7576764807400442, fake_2751321871941368, fake_7670467332129103 result, different session: fake_8247675995424364, fake_3623040345849331, fake_7576764807400442, fake_2751321871941368, fake_7670467332129103 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_07070772728640762, fake_1851465193368398, fake_5282374329772237, fake_2747732830132157, fake_516330728110781 result, different session: fake_07070772728640762, fake_1851465193368398, fake_5282374329772237, fake_2747732830132157, fake_516330728110781 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_8392705575256632, fake_5191500111886578, fake_07499894279135666, fake_8016777955472301, fake_8230078802575178 result, different session: fake_8392705575256632, fake_5191500111886578, fake_07499894279135666, fake_8016777955472301, fake_8230078802575178 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_040485687948658367, fake_1529286951359501, fake_8284015860886549, fake_10483825407073444, fake_0005078595788299278 result, different session: fake_5877714322517162, fake_5702025399094446, fake_9009883461064332, fake_14925330298301764, fake_24179694056095058 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_6539588192338064, fake_9157487153269397, fake_7629853162084901, fake_21296647495332977, fake_29662997736157326 result, different session: fake_6539588192338064, fake_9157487153269397, fake_7629853162084901, fake_21296647495332977, fake_29662997736157326 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_6263808705271001, fake_9382723369057278, fake_19369913365641067, fake_9186601138726729, fake_6022552214829695 result, different session: fake_6263808705271001, fake_9382723369057278, fake_19369913365641067, fake_9186601138726729, fake_6022552214829695 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_8731347314011002, fake_16591927965494557, fake_07588249095007593, fake_5876463231096885, fake_04334611526752341 result, different session: fake_8731347314011002, fake_16591927965494557, fake_07588249095007593, fake_5876463231096885, fake_04334611526752341 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_962216654831388, fake_6651738206469353, fake_6527140515862875, fake_30723289708910206, fake_21049391070329015 result, different session: fake_08765689127453458, fake_3495782881177443, fake_7373252955803775, fake_48574220231891396, fake_62851599972011 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
fetch 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  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, 2 result, different session: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
font 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
iframe 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
image 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
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: 9ac39a85-8ab7-4701-a180-e0258ffed06d_1p, c8bec77d-63ba-4341-917e-b5408c92dcc5_1p, 042d8f53-c559-43a6-a8a7-47ddc37130bd_1p, 85f1f68b-7073-4597-b535-eb74b80aadd1_1p, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_1p result, different session: 9ac39a85-8ab7-4701-a180-e0258ffed06d_1p, c8bec77d-63ba-4341-917e-b5408c92dcc5_1p, 042d8f53-c559-43a6-a8a7-47ddc37130bd_1p, 85f1f68b-7073-4597-b535-eb74b80aadd1_1p, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_1p, d34c57c7-5d97-4e88-914b-e48338759e2a_1p, f06fc2c4-1496-40d7-845d-8ece8392ef42_1p, 61475483-e492-4381-8454-dd307e85da96_1p, 52fa6d5a-aeff-4339-89d9-416078067571_1p result, different session: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_1p, d34c57c7-5d97-4e88-914b-e48338759e2a_1p, f06fc2c4-1496-40d7-845d-8ece8392ef42_1p, 61475483-e492-4381-8454-dd307e85da96_1p, 52fa6d5a-aeff-4339-89d9-416078067571_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: 622f476f-496f-479a-8210-d893d45008e3_1p, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_1p, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_1p, 100e6983-45f4-461c-b471-82142ccb28cd_1p, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_1p result, different session: 622f476f-496f-479a-8210-d893d45008e3_1p, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_1p, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_1p, 100e6983-45f4-461c-b471-82142ccb28cd_1p, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: 85251b22-cbd9-4601-86ba-3b4c577c26c1_1p, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_1p, 326d2d25-8350-4dda-9fd0-47313dcd2617_1p, e70d9262-de62-48cc-9f39-32381c778d9d_1p, 31abe5a2-5672-4dbb-8117-f5bd46034efe_1p result, different session: 85251b22-cbd9-4601-86ba-3b4c577c26c1_1p, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_1p, 326d2d25-8350-4dda-9fd0-47313dcd2617_1p, e70d9262-de62-48cc-9f39-32381c778d9d_1p, 31abe5a2-5672-4dbb-8117-f5bd46034efe_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: 4ba06d12-1bda-476e-9b5d-64a1e308d511_1p, 3deec293-7da9-484f-9c66-ef3e09af2d78_1p, d9848e10-1748-434d-bc7a-875a9ebb9509_1p, 4452583e-047f-42e6-a3ed-e10ee6e982fe_1p, 479d2517-702a-4d44-916c-2d5a02f1c810_1p result, different session: 4ba06d12-1bda-476e-9b5d-64a1e308d511_1p, 3deec293-7da9-484f-9c66-ef3e09af2d78_1p, d9848e10-1748-434d-bc7a-875a9ebb9509_1p, 4452583e-047f-42e6-a3ed-e10ee6e982fe_1p, 479d2517-702a-4d44-916c-2d5a02f1c810_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: 5540e25b-012b-4070-9f09-14c82b3a2944_1p, 93ebb577-e88b-4615-b2cc-ca6180e5fac5_1p, 1b237b30-50d2-4301-912d-456f798b95b3_1p, 3cd2a582-1831-4424-bfa6-c9d23d56df01_1p, 52f72e7e-5a9d-48af-a650-bc2301651dea_1p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 08da9409-753a-47f6-b943-3eb2da2e5f43_1p, 33078437-5ab2-47db-8711-876cffa90f94_1p, f2b1405c-9823-481d-a5f1-9523a11a5dce_1p, 6fea33c4-c1e6-4894-882d-67ab5486a325_1p, 62b540c8-6950-43b3-a590-520b11bc8039_1p result, different session: 08da9409-753a-47f6-b943-3eb2da2e5f43_1p, 33078437-5ab2-47db-8711-876cffa90f94_1p, f2b1405c-9823-481d-a5f1-9523a11a5dce_1p, 6fea33c4-c1e6-4894-882d-67ab5486a325_1p, 62b540c8-6950-43b3-a590-520b11bc8039_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_1p, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_1p, 121286d6-62fe-484f-8299-ffd8fd69ba14_1p, fb9c38e8-5ae6-477a-ba7d-c9963e355902_1p, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_1p result, different session: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_1p, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_1p, 121286d6-62fe-484f-8299-ffd8fd69ba14_1p, fb9c38e8-5ae6-477a-ba7d-c9963e355902_1p, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: f7843a45-1904-4d46-84c1-f7a99c2a0667_1p, c870d944-a0e7-4780-b7d2-de9964a7e828_1p, 2aea4ed2-7103-4b43-b845-7479023e7c3c_1p, debd74ae-cf0e-4c43-8f81-8525a239a8aa_1p, f0af8fdf-b92b-4604-bcc8-060168311300_1p result, different session: f7843a45-1904-4d46-84c1-f7a99c2a0667_1p, c870d944-a0e7-4780-b7d2-de9964a7e828_1p, 2aea4ed2-7103-4b43-b845-7479023e7c3c_1p, debd74ae-cf0e-4c43-8f81-8525a239a8aa_1p, f0af8fdf-b92b-4604-bcc8-060168311300_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: f3ed2451-6e30-4324-8498-a6d856dec785_1p, 49ee8cd6-647b-49c8-adf1-766644f99437_1p, 0e365bcc-4492-4d7a-b413-87412097f819_1p, fb062a09-219d-404b-a2a8-c3d0dd55cf64_1p, d9e3f96c-9618-4a86-a8b6-e344225ea20e_1p result, different session: f3ed2451-6e30-4324-8498-a6d856dec785_1p, 49ee8cd6-647b-49c8-adf1-766644f99437_1p, 0e365bcc-4492-4d7a-b413-87412097f819_1p, fb062a09-219d-404b-a2a8-c3d0dd55cf64_1p, d9e3f96c-9618-4a86-a8b6-e344225ea20e_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: 9ac39a85-8ab7-4701-a180-e0258ffed06d_1p, c8bec77d-63ba-4341-917e-b5408c92dcc5_1p, 042d8f53-c559-43a6-a8a7-47ddc37130bd_1p, 85f1f68b-7073-4597-b535-eb74b80aadd1_1p, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_1p result, different session: 9ac39a85-8ab7-4701-a180-e0258ffed06d_1p, c8bec77d-63ba-4341-917e-b5408c92dcc5_1p, 042d8f53-c559-43a6-a8a7-47ddc37130bd_1p, 85f1f68b-7073-4597-b535-eb74b80aadd1_1p, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_1p, d34c57c7-5d97-4e88-914b-e48338759e2a_1p, f06fc2c4-1496-40d7-845d-8ece8392ef42_1p, 61475483-e492-4381-8454-dd307e85da96_1p, 52fa6d5a-aeff-4339-89d9-416078067571_1p result, different session: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_1p, d34c57c7-5d97-4e88-914b-e48338759e2a_1p, f06fc2c4-1496-40d7-845d-8ece8392ef42_1p, 61475483-e492-4381-8454-dd307e85da96_1p, 52fa6d5a-aeff-4339-89d9-416078067571_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 622f476f-496f-479a-8210-d893d45008e3_1p, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_1p, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_1p, 100e6983-45f4-461c-b471-82142ccb28cd_1p, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_1p result, different session: 622f476f-496f-479a-8210-d893d45008e3_1p, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_1p, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_1p, 100e6983-45f4-461c-b471-82142ccb28cd_1p, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 85251b22-cbd9-4601-86ba-3b4c577c26c1_1p, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_1p, 326d2d25-8350-4dda-9fd0-47313dcd2617_1p, e70d9262-de62-48cc-9f39-32381c778d9d_1p, 31abe5a2-5672-4dbb-8117-f5bd46034efe_1p result, different session: 85251b22-cbd9-4601-86ba-3b4c577c26c1_1p, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_1p, 326d2d25-8350-4dda-9fd0-47313dcd2617_1p, e70d9262-de62-48cc-9f39-32381c778d9d_1p, 31abe5a2-5672-4dbb-8117-f5bd46034efe_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 4ba06d12-1bda-476e-9b5d-64a1e308d511_1p, 3deec293-7da9-484f-9c66-ef3e09af2d78_1p, d9848e10-1748-434d-bc7a-875a9ebb9509_1p, 4452583e-047f-42e6-a3ed-e10ee6e982fe_1p, 479d2517-702a-4d44-916c-2d5a02f1c810_1p result, different session: 4ba06d12-1bda-476e-9b5d-64a1e308d511_1p, 3deec293-7da9-484f-9c66-ef3e09af2d78_1p, d9848e10-1748-434d-bc7a-875a9ebb9509_1p, 4452583e-047f-42e6-a3ed-e10ee6e982fe_1p, 479d2517-702a-4d44-916c-2d5a02f1c810_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 5540e25b-012b-4070-9f09-14c82b3a2944_1p, 93ebb577-e88b-4615-b2cc-ca6180e5fac5_1p, 1b237b30-50d2-4301-912d-456f798b95b3_1p, 3cd2a582-1831-4424-bfa6-c9d23d56df01_1p, 52f72e7e-5a9d-48af-a650-bc2301651dea_1p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 08da9409-753a-47f6-b943-3eb2da2e5f43_1p, 33078437-5ab2-47db-8711-876cffa90f94_1p, f2b1405c-9823-481d-a5f1-9523a11a5dce_1p, 6fea33c4-c1e6-4894-882d-67ab5486a325_1p, 62b540c8-6950-43b3-a590-520b11bc8039_1p result, different session: 08da9409-753a-47f6-b943-3eb2da2e5f43_1p, 33078437-5ab2-47db-8711-876cffa90f94_1p, f2b1405c-9823-481d-a5f1-9523a11a5dce_1p, 6fea33c4-c1e6-4894-882d-67ab5486a325_1p, 62b540c8-6950-43b3-a590-520b11bc8039_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_1p, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_1p, 121286d6-62fe-484f-8299-ffd8fd69ba14_1p, fb9c38e8-5ae6-477a-ba7d-c9963e355902_1p, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_1p result, different session: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_1p, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_1p, 121286d6-62fe-484f-8299-ffd8fd69ba14_1p, fb9c38e8-5ae6-477a-ba7d-c9963e355902_1p, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: f7843a45-1904-4d46-84c1-f7a99c2a0667_1p, c870d944-a0e7-4780-b7d2-de9964a7e828_1p, 2aea4ed2-7103-4b43-b845-7479023e7c3c_1p, debd74ae-cf0e-4c43-8f81-8525a239a8aa_1p, f0af8fdf-b92b-4604-bcc8-060168311300_1p result, different session: f7843a45-1904-4d46-84c1-f7a99c2a0667_1p, c870d944-a0e7-4780-b7d2-de9964a7e828_1p, 2aea4ed2-7103-4b43-b845-7479023e7c3c_1p, debd74ae-cf0e-4c43-8f81-8525a239a8aa_1p, f0af8fdf-b92b-4604-bcc8-060168311300_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: f3ed2451-6e30-4324-8498-a6d856dec785_1p, 49ee8cd6-647b-49c8-adf1-766644f99437_1p, 0e365bcc-4492-4d7a-b413-87412097f819_1p, fb062a09-219d-404b-a2a8-c3d0dd55cf64_1p, d9e3f96c-9618-4a86-a8b6-e344225ea20e_1p result, different session: f3ed2451-6e30-4324-8498-a6d856dec785_1p, 49ee8cd6-647b-49c8-adf1-766644f99437_1p, 0e365bcc-4492-4d7a-b413-87412097f819_1p, fb062a09-219d-404b-a2a8-c3d0dd55cf64_1p, d9e3f96c-9618-4a86-a8b6-e344225ea20e_1p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
Cross-session third-party tracking 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, h2 result, different session: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, h2 result, different session: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, h2 result, different session: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, h2 result, different session: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, h2 result, different session: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, h2 result, different session: h2, h2, h2, h2, h2 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, h2 result, different session: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, h2 result, different session: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, h2 result, different session: h3, h3, h3, h3, h3 unsupported: true, true, true, true, true passed: undefined test failed: false, 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, h2 result, different session: h2, h2, h2, h2, h2 unsupported: true, true, true, true, true passed: undefined test failed: false, 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=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: e917fd3f-2558-42ac-b08f-c6cd639cb554_3p, e917fd3f-2558-42ac-b08f-c6cd639cb554_3p, e917fd3f-2558-42ac-b08f-c6cd639cb554_3p, e917fd3f-2558-42ac-b08f-c6cd639cb554_3p, e917fd3f-2558-42ac-b08f-c6cd639cb554_3p result, different session: e917fd3f-2558-42ac-b08f-c6cd639cb554_3p, e917fd3f-2558-42ac-b08f-c6cd639cb554_3p, e917fd3f-2558-42ac-b08f-c6cd639cb554_3p, e917fd3f-2558-42ac-b08f-c6cd639cb554_3p, e917fd3f-2558-42ac-b08f-c6cd639cb554_3p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: a715dfe4-a7ff-4477-929c-50938cc67332_3p, a715dfe4-a7ff-4477-929c-50938cc67332_3p, a715dfe4-a7ff-4477-929c-50938cc67332_3p, a715dfe4-a7ff-4477-929c-50938cc67332_3p, a715dfe4-a7ff-4477-929c-50938cc67332_3p result, different session: a715dfe4-a7ff-4477-929c-50938cc67332_3p, a715dfe4-a7ff-4477-929c-50938cc67332_3p, a715dfe4-a7ff-4477-929c-50938cc67332_3p, a715dfe4-a7ff-4477-929c-50938cc67332_3p, a715dfe4-a7ff-4477-929c-50938cc67332_3p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: fcb49e69-7fe4-48a9-88b1-353f709309bc_3p, fcb49e69-7fe4-48a9-88b1-353f709309bc_3p, fcb49e69-7fe4-48a9-88b1-353f709309bc_3p, fcb49e69-7fe4-48a9-88b1-353f709309bc_3p, fcb49e69-7fe4-48a9-88b1-353f709309bc_3p result, different session: fcb49e69-7fe4-48a9-88b1-353f709309bc_3p, fcb49e69-7fe4-48a9-88b1-353f709309bc_3p, fcb49e69-7fe4-48a9-88b1-353f709309bc_3p, fcb49e69-7fe4-48a9-88b1-353f709309bc_3p, fcb49e69-7fe4-48a9-88b1-353f709309bc_3p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_3p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_3p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_3p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_3p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_3p result, different session: 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_3p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_3p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_3p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_3p, 895b0837-dbb7-43a2-a447-2bf0b69b0fe5_3p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: 79784830-014a-400f-b0f9-624dcd93d540_3p, 79784830-014a-400f-b0f9-624dcd93d540_3p, 79784830-014a-400f-b0f9-624dcd93d540_3p, 79784830-014a-400f-b0f9-624dcd93d540_3p, 79784830-014a-400f-b0f9-624dcd93d540_3p result, different session: 79784830-014a-400f-b0f9-624dcd93d540_3p, 79784830-014a-400f-b0f9-624dcd93d540_3p, 79784830-014a-400f-b0f9-624dcd93d540_3p, 79784830-014a-400f-b0f9-624dcd93d540_3p, 79784830-014a-400f-b0f9-624dcd93d540_3p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') result, different session: Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url'), Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: f6eca5e9-57f3-489d-8966-88072f14efaf_3p, f6eca5e9-57f3-489d-8966-88072f14efaf_3p, f6eca5e9-57f3-489d-8966-88072f14efaf_3p, f6eca5e9-57f3-489d-8966-88072f14efaf_3p, f6eca5e9-57f3-489d-8966-88072f14efaf_3p result, different session: f6eca5e9-57f3-489d-8966-88072f14efaf_3p, f6eca5e9-57f3-489d-8966-88072f14efaf_3p, f6eca5e9-57f3-489d-8966-88072f14efaf_3p, f6eca5e9-57f3-489d-8966-88072f14efaf_3p, f6eca5e9-57f3-489d-8966-88072f14efaf_3p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: 4e05b678-bc4e-4360-baca-31ef3e710454_3p, 4e05b678-bc4e-4360-baca-31ef3e710454_3p, 4e05b678-bc4e-4360-baca-31ef3e710454_3p, 4e05b678-bc4e-4360-baca-31ef3e710454_3p, 4e05b678-bc4e-4360-baca-31ef3e710454_3p result, different session: 4e05b678-bc4e-4360-baca-31ef3e710454_3p, 4e05b678-bc4e-4360-baca-31ef3e710454_3p, 4e05b678-bc4e-4360-baca-31ef3e710454_3p, 4e05b678-bc4e-4360-baca-31ef3e710454_3p, 4e05b678-bc4e-4360-baca-31ef3e710454_3p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same session: 2eb2c6db-6425-41c8-96a1-02cfbab25729_3p, 2eb2c6db-6425-41c8-96a1-02cfbab25729_3p, 2eb2c6db-6425-41c8-96a1-02cfbab25729_3p, 2eb2c6db-6425-41c8-96a1-02cfbab25729_3p, 2eb2c6db-6425-41c8-96a1-02cfbab25729_3p result, different session: 2eb2c6db-6425-41c8-96a1-02cfbab25729_3p, 2eb2c6db-6425-41c8-96a1-02cfbab25729_3p, 2eb2c6db-6425-41c8-96a1-02cfbab25729_3p, 2eb2c6db-6425-41c8-96a1-02cfbab25729_3p, 2eb2c6db-6425-41c8-96a1-02cfbab25729_3p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: 463b4922-4edb-4a1a-a19b-d9f63985520d_3p, 463b4922-4edb-4a1a-a19b-d9f63985520d_3p, 463b4922-4edb-4a1a-a19b-d9f63985520d_3p, 463b4922-4edb-4a1a-a19b-d9f63985520d_3p, 463b4922-4edb-4a1a-a19b-d9f63985520d_3p result, different session: 463b4922-4edb-4a1a-a19b-d9f63985520d_3p, 463b4922-4edb-4a1a-a19b-d9f63985520d_3p, 463b4922-4edb-4a1a-a19b-d9f63985520d_3p, 463b4922-4edb-4a1a-a19b-d9f63985520d_3p, 463b4922-4edb-4a1a-a19b-d9f63985520d_3p unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
cookie (HTTP)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${baseURI}cookie?secret=${secret}_http`); } read: async () => { // Test if we now send a requests with a 'cookie' header containing the secret. let response = await fetch(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
cookie (JS)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (secret) => { document.cookie = `secret=${secret}_js; max-age=3600; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same session: , , , , result, different session: , , , , unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
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: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (data) => { const msPerHour = 60 * 60 * 1000; if (!window.cookieStore) { throw new Error("Unsupported"); } window.cookieStore.set({ name: "partition_test", value: data, expires: Date.now() + msPerHour, sameSite: "none" }); } read: async () => { if (!window.cookieStore) { throw new Error("Unsupported"); } const cookie = await window.cookieStore.get("partition_test"); if (!cookie) { return null; } return cookie.value; } result, same session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported result, different session: Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported, Error: Unsupported unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
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_7718563229416515, fake_2938781473400469, fake_6491154101417353, fake_6265721126671302, fake_8379221914281183 result, different session: fake_7718563229416515, fake_2938781473400469, fake_6491154101417353, fake_6265721126671302, fake_8379221914281183 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_09008324519101718, fake_8347951808118366, fake_7863726016202817, fake_5423808896256666, fake_6228895520778779 result, different session: fake_09008324519101718, fake_8347951808118366, fake_7863726016202817, fake_5423808896256666, fake_6228895520778779 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_6945780654286866, fake_11688575494624209, fake_05579619310850181, fake_38996476212717446, fake_20258950891075567 result, different session: fake_6945780654286866, fake_11688575494624209, fake_05579619310850181, fake_38996476212717446, fake_20258950891075567 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_3960156213577113, fake_4795469481623553, fake_07734596382807046, fake_9101150067855868, fake_500240210230767 result, different session: fake_3960156213577113, fake_4795469481623553, fake_07734596382807046, fake_9101150067855868, fake_500240210230767 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_7481123077764069, fake_24488708314787977, fake_43327118533678455, fake_4876310886650228, fake_9881299114676934 result, different session: fake_7481123077764069, fake_24488708314787977, fake_43327118533678455, fake_4876310886650228, fake_9881299114676934 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_7483401065575399, fake_36887742125110123, fake_2710846649129912, fake_10830947831807936, fake_7946424892318831 result, different session: fake_5433160359260265, fake_126441401005422, fake_2459736687879146, fake_3103497392140868, fake_5087104185773077 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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_6834552321424605, fake_8418872929071941, fake_24216488603162634, fake_3652526722154217, fake_18178413630476564 result, different session: fake_6834552321424605, fake_8418872929071941, fake_24216488603162634, fake_3652526722154217, fake_18178413630476564 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_931085725411182, fake_8821564426509516, fake_24595612753416685, fake_9901869443896152, fake_5453570195896464 result, different session: fake_931085725411182, fake_8821564426509516, fake_24595612753416685, fake_9901869443896152, fake_5453570195896464 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_49164276428981624, fake_6754845149575832, fake_018067652939356194, fake_3404279289969261, fake_0994720733323875 result, different session: fake_49164276428981624, fake_6754845149575832, fake_018067652939356194, fake_3404279289969261, fake_0994720733323875 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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_6739321617791687, fake_7904155259973626, fake_8268425228462652, fake_8686611981528962, fake_7612796275871518 result, different session: fake_17346165155494275, fake_7022807900756876, fake_2729640445793988, fake_3791284952053551, fake_05652339546323737 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(2000); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
fetch 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  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, 2 result, different session: 3, 3, 3, 3, 3 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); return key; } read: async (key) => { let response = await fetch(testURI("resource", "fetch", key), {cache: "force-cache"}); let countResponse = await fetch(testURI("ctr", "fetch", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
font 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { const text = document.createElement("span"); text.id = "text"; text.innerText = "test"; document.body.appendChild(text); const originalWidth = text.getBoundingClientRect().width; let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } #text { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); let newWidth; do { await sleepMs(100); newWidth = text.getBoundingClientRect().width; } while (newWidth < 0 || newWidth === originalWidth) let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
iframe 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); iframe.addEventListener("load", () => resolve(key), {once: true}); iframe.src = testURI("resource", "page", key); }) read: async (key) => { let iframe = document.createElement("iframe"); document.body.appendChild(iframe); let iframeLoadPromise = new Promise((resolve, reject) => { iframe.addEventListener("load", resolve, {once: true}); }); let address = testURI("resource", "page", key); iframe.src = address; await iframeLoadPromise; let response = await fetch( testURI("ctr", "page", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
image 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
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: 9ac39a85-8ab7-4701-a180-e0258ffed06d_3p, c8bec77d-63ba-4341-917e-b5408c92dcc5_3p, 042d8f53-c559-43a6-a8a7-47ddc37130bd_3p, 85f1f68b-7073-4597-b535-eb74b80aadd1_3p, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_3p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_3p, d34c57c7-5d97-4e88-914b-e48338759e2a_3p, f06fc2c4-1496-40d7-845d-8ece8392ef42_3p, 61475483-e492-4381-8454-dd307e85da96_3p, 52fa6d5a-aeff-4339-89d9-416078067571_3p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 622f476f-496f-479a-8210-d893d45008e3_3p, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_3p, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_3p, 100e6983-45f4-461c-b471-82142ccb28cd_3p, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_3p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 85251b22-cbd9-4601-86ba-3b4c577c26c1_3p, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_3p, 326d2d25-8350-4dda-9fd0-47313dcd2617_3p, e70d9262-de62-48cc-9f39-32381c778d9d_3p, 31abe5a2-5672-4dbb-8117-f5bd46034efe_3p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 4ba06d12-1bda-476e-9b5d-64a1e308d511_3p, 3deec293-7da9-484f-9c66-ef3e09af2d78_3p, d9848e10-1748-434d-bc7a-875a9ebb9509_3p, 4452583e-047f-42e6-a3ed-e10ee6e982fe_3p, 479d2517-702a-4d44-916c-2d5a02f1c810_3p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 5540e25b-012b-4070-9f09-14c82b3a2944_3p, 93ebb577-e88b-4615-b2cc-ca6180e5fac5_3p, 1b237b30-50d2-4301-912d-456f798b95b3_3p, 3cd2a582-1831-4424-bfa6-c9d23d56df01_3p, 52f72e7e-5a9d-48af-a650-bc2301651dea_3p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 08da9409-753a-47f6-b943-3eb2da2e5f43_3p, 33078437-5ab2-47db-8711-876cffa90f94_3p, f2b1405c-9823-481d-a5f1-9523a11a5dce_3p, 6fea33c4-c1e6-4894-882d-67ab5486a325_3p, 62b540c8-6950-43b3-a590-520b11bc8039_3p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_3p, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_3p, 121286d6-62fe-484f-8299-ffd8fd69ba14_3p, fb9c38e8-5ae6-477a-ba7d-c9963e355902_3p, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_3p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: f7843a45-1904-4d46-84c1-f7a99c2a0667_3p, c870d944-a0e7-4780-b7d2-de9964a7e828_3p, 2aea4ed2-7103-4b43-b845-7479023e7c3c_3p, debd74ae-cf0e-4c43-8f81-8525a239a8aa_3p, f0af8fdf-b92b-4604-bcc8-060168311300_3p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: f3ed2451-6e30-4324-8498-a6d856dec785_3p, 49ee8cd6-647b-49c8-adf1-766644f99437_3p, 0e365bcc-4492-4d7a-b413-87412097f819_3p, fb062a09-219d-404b-a2a8-c3d0dd55cf64_3p, d9e3f96c-9618-4a86-a8b6-e344225ea20e_3p result, different session: undefined unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: 9ac39a85-8ab7-4701-a180-e0258ffed06d_3p, c8bec77d-63ba-4341-917e-b5408c92dcc5_3p, 042d8f53-c559-43a6-a8a7-47ddc37130bd_3p, 85f1f68b-7073-4597-b535-eb74b80aadd1_3p, 36c60da1-6913-4c2a-a33f-4f6aaed4c1e3_3p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: ecd8774e-b3ff-41e4-95e4-1f4d6a473701_3p, d34c57c7-5d97-4e88-914b-e48338759e2a_3p, f06fc2c4-1496-40d7-845d-8ece8392ef42_3p, 61475483-e492-4381-8454-dd307e85da96_3p, 52fa6d5a-aeff-4339-89d9-416078067571_3p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 622f476f-496f-479a-8210-d893d45008e3_3p, 86f0cf10-7cd5-4f6e-aa3d-fb45dd865f76_3p, a64fae45-ad10-4bf6-a2c5-c0a44dfe8f87_3p, 100e6983-45f4-461c-b471-82142ccb28cd_3p, f1b619cd-c0ed-4abb-a1fa-4e16a5d5104e_3p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 85251b22-cbd9-4601-86ba-3b4c577c26c1_3p, 99137440-3c3f-4062-b7b6-b8b5656fe3e3_3p, 326d2d25-8350-4dda-9fd0-47313dcd2617_3p, e70d9262-de62-48cc-9f39-32381c778d9d_3p, 31abe5a2-5672-4dbb-8117-f5bd46034efe_3p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 4ba06d12-1bda-476e-9b5d-64a1e308d511_3p, 3deec293-7da9-484f-9c66-ef3e09af2d78_3p, d9848e10-1748-434d-bc7a-875a9ebb9509_3p, 4452583e-047f-42e6-a3ed-e10ee6e982fe_3p, 479d2517-702a-4d44-916c-2d5a02f1c810_3p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 5540e25b-012b-4070-9f09-14c82b3a2944_3p, 93ebb577-e88b-4615-b2cc-ca6180e5fac5_3p, 1b237b30-50d2-4301-912d-456f798b95b3_3p, 3cd2a582-1831-4424-bfa6-c9d23d56df01_3p, 52f72e7e-5a9d-48af-a650-bc2301651dea_3p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: 08da9409-753a-47f6-b943-3eb2da2e5f43_3p, 33078437-5ab2-47db-8711-876cffa90f94_3p, f2b1405c-9823-481d-a5f1-9523a11a5dce_3p, 6fea33c4-c1e6-4894-882d-67ab5486a325_3p, 62b540c8-6950-43b3-a590-520b11bc8039_3p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: fd2e2d22-3111-4ff5-9ea9-f2a84feff7e9_3p, 6a839bd1-4a0e-4aeb-81e8-1f56cb65c5bf_3p, 121286d6-62fe-484f-8299-ffd8fd69ba14_3p, fb9c38e8-5ae6-477a-ba7d-c9963e355902_3p, 13cd54ac-fe53-46ba-8048-e7a79fcb47ea_3p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: f7843a45-1904-4d46-84c1-f7a99c2a0667_3p, c870d944-a0e7-4780-b7d2-de9964a7e828_3p, 2aea4ed2-7103-4b43-b845-7479023e7c3c_3p, debd74ae-cf0e-4c43-8f81-8525a239a8aa_3p, f0af8fdf-b92b-4604-bcc8-060168311300_3p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same session: f3ed2451-6e30-4324-8498-a6d856dec785_3p, 49ee8cd6-647b-49c8-adf1-766644f99437_3p, 0e365bcc-4492-4d7a-b413-87412097f819_3p, fb062a09-219d-404b-a2a8-c3d0dd55cf64_3p, d9e3f96c-9618-4a86-a8b6-e344225ea20e_3p result, different session: , , , , unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, 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: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
write: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); return key; } read: async (key) => { let link = document.createElement("link"); link.rel = "prefetch"; link.href = testURI("resource", "prefetch", key); document.getElementsByTagName("head")[0].appendChild(link); await sleepMs(500); let response = await fetch( testURI("ctr", "prefetch", key), {"cache": "reload"}); let countString = (await response.text()).trim(); if (parseInt(countString) === 0) { throw new Error("No requests received"); } return countString; } result, same session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received result, different session: Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received, Error: No requests received unsupported: true, true, true, true, true passed: undefined test failed: false, false, false, false, false
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: Web SQL is deprecated, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 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, Error: Web SQL is deprecated unsupported: true, true, true, true, true passed: undefined test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, false, false, false, false
  write: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; return key; } read: async (key) => { const req = new XMLHttpRequest(); const loadPromise = new Promise(resolve => req.addEventListener("load", resolve)); req.open("GET", testURI("resource", "xhr", key)); req.send(); await loadPromise; let countResponse = await fetch(testURI("ctr", "xhr", key), {cache: "reload"}); return (await countResponse.text()).trim(); } result, same session: 1, 1, 1, 1, 1 result, different session: 1, 1, 1, 1, 1 unsupported: false, false, false, false, false passed: false, false, false, false, false test failed: false, 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, 1 result, different session: 2, 2, 2, 2, 2 unsupported: false, false, false, false, false passed: true, true, true, true, true test failed: false, false, false, false, false