iOS Browsers


brave
1.45

chrome
107.5304

duckduckgo
7.70

edge
107.1418

firefox
107.0

focus
107.0

opera
3.3

safari
16.1

yandex
2211.3
State Partitioning testsA 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 = ""; await fetch("https://altsvc.privacytests2.org:4433/clear"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache await fetch("https://altsvc.privacytests2.org:4433/set"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: h3 result, different first party: h2 unsupported: false passed: true test failed: false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; await fetch("https://altsvc.privacytests2.org:4433/clear"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache await fetch("https://altsvc.privacytests2.org:4433/set"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: h3 result, different first party: h2 unsupported: false passed: true test failed: false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; await fetch("https://altsvc.privacytests2.org:4433/clear"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache await fetch("https://altsvc.privacytests2.org:4433/set"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported result, different first party: h3 unsupported: true passed: undefined test failed: false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; await fetch("https://altsvc.privacytests2.org:4433/clear"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache await fetch("https://altsvc.privacytests2.org:4433/set"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: h3 result, different first party: h2 unsupported: false passed: true test failed: false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; await fetch("https://altsvc.privacytests2.org:4433/clear"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache await fetch("https://altsvc.privacytests2.org:4433/set"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported result, different first party: h3 unsupported: true passed: undefined test failed: false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; await fetch("https://altsvc.privacytests2.org:4433/clear"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache await fetch("https://altsvc.privacytests2.org:4433/set"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported result, different first party: h3 unsupported: true passed: undefined test failed: false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; await fetch("https://altsvc.privacytests2.org:4433/clear"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache await fetch("https://altsvc.privacytests2.org:4433/set"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: h3 result, different first party: h2 unsupported: false passed: true test failed: false
  write: async () => { // Clear Alt-Svc caching first. let responseText = ""; await fetch("https://altsvc.privacytests2.org:4433/clear"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache await fetch("https://altsvc.privacytests2.org:4433/set"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: h3 result, different first party: h2 unsupported: false passed: true test failed: false
write: async () => { // Clear Alt-Svc caching first. let responseText = ""; await fetch("https://altsvc.privacytests2.org:4433/clear"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after clear:", responseText); // Store "h3" state in Alt-Svc cache await fetch("https://altsvc.privacytests2.org:4433/set"); await sleepMs(100); responseText = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); console.log("after set:", responseText); } read: async () => { const protocol = await fetchText("https://altsvc.privacytests2.org:4433/protocol"); if ((new URL(location)).searchParams.get("thirdparty") === "same") { if (protocol !== "h3") { throw new Error("Unsupported"); } } return protocol; } result, same first party: Error: Unsupported result, different first party: h3 unsupported: true passed: undefined test failed: 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=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 8d4c3b04-1c9c-4118-ab88-18d8216c0933 result, different first party: 8d4c3b04-1c9c-4118-ab88-18d8216c0933 unsupported: false passed: false test failed: false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${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: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf result, different first party: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf unsupported: false passed: false test failed: 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=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 07383e38-6a64-45a4-9d54-44460860e159 result, different first party: 07383e38-6a64-45a4-9d54-44460860e159 unsupported: false passed: false test failed: false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${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: 1bde12f7-ff50-435c-87f6-c695f99320b4 result, different first party: 1bde12f7-ff50-435c-87f6-c695f99320b4 unsupported: false passed: false test failed: 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=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: 3ce76e00-7743-4b76-ae2c-f9532935dfa2 result, different first party: 3ce76e00-7743-4b76-ae2c-f9532935dfa2 unsupported: false passed: false test failed: false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${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 result, different first party: Error: Load failed unsupported: false passed: undefined test failed: 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=${secret}`); let result = await response.json(); let blobUrl = decodeURIComponent(result.blobUrl); let blobResponse = await fetch(blobUrl); return blobResponse.text(); } result, same first party: f0d481b6-9a56-40f3-91f8-40e1ebcc664a result, different first party: f0d481b6-9a56-40f3-91f8-40e1ebcc664a unsupported: false passed: false test failed: false
  write: (secret) => { try { let blobURL = URL.createObjectURL(new Blob([secret])); fetch(`${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: c31d3992-0ff0-4221-85c3-cb903982c96f result, different first party: c31d3992-0ff0-4221-85c3-cb903982c96f unsupported: false passed: false test failed: 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: 44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: 44a00af5-7bef-4c52-88aa-059c77acb0ea unsupported: false passed: false test failed: 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: 8d4c3b04-1c9c-4118-ab88-18d8216c0933 result, different first party: Error: no BroadcastChannel message unsupported: false passed: true test failed: 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: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf result, different first party: Error: no BroadcastChannel message unsupported: false passed: true test failed: 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: 07383e38-6a64-45a4-9d54-44460860e159 result, different first party: Error: no BroadcastChannel message unsupported: false passed: true test failed: 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: 1bde12f7-ff50-435c-87f6-c695f99320b4 result, different first party: Error: no BroadcastChannel message unsupported: false passed: true test failed: 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: 3ce76e00-7743-4b76-ae2c-f9532935dfa2 result, different first party: Error: no BroadcastChannel message unsupported: false passed: true test failed: 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 result, different first party: Error: no BroadcastChannel message unsupported: false passed: undefined test failed: 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: f0d481b6-9a56-40f3-91f8-40e1ebcc664a result, different first party: Error: no BroadcastChannel message unsupported: false passed: true test failed: 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: c31d3992-0ff0-4221-85c3-cb903982c96f result, different first party: Error: no BroadcastChannel message unsupported: false passed: true test failed: 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: 44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: Error: no BroadcastChannel message unsupported: false passed: true test failed: 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: 3307da97-e4e1-471b-b427-4af1924af170 result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false passed: true test failed: false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: 04b730b5-2a62-4ebb-9623-133f9e94572b result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false passed: true test failed: false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: 609c3156-6f13-41fd-ae63-02de22f28258 result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false passed: true test failed: false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: b6f25f5c-2c22-4433-863f-648faf646202 result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false passed: true test failed: false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: e625cbe5-1d75-4d2f-ba75-f1ad0d11a0af result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false passed: true test failed: false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: d528b5fa-d056-4015-9d6b-730f8cd1f6e1 result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false passed: true test failed: false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: 587e3bce-79e7-4a18-a415-70eaf7c700dd result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false passed: true test failed: false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${key}`]); } catch (e) { throw new Error("Unsupported"); } } read: async () => { let cache = await caches.open("supercookies"); let cacheKeys = await cache.keys(); let url = cacheKeys[0].url; return (new URL(url)).searchParams.get("key"); } result, same first party: bb40dd3f-3c4c-43fe-9f85-343ffb7a7136 result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false passed: true test failed: false
  write: async (key) => { try { let cache = await caches.open("supercookies"); cache.addAll([`test.css?key=${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: 44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: Error: undefined is not an object (evaluating 'cacheKeys[0].url') unsupported: false passed: true test failed: false
cookie (HTTP)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
  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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 8d4c3b04-1c9c-4118-ab88-18d8216c0933_http result, different first party: null unsupported: false passed: true test failed: false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf_http result, different first party: null unsupported: false passed: true test failed: 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 07383e38-6a64-45a4-9d54-44460860e159_http result, different first party: null unsupported: false passed: true test failed: false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: 1bde12f7-ff50-435c-87f6-c695f99320b4_http result, different first party: null unsupported: false passed: true test failed: 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 3ce76e00-7743-4b76-ae2c-f9532935dfa2_http result, different first party: null unsupported: false passed: true test failed: false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: d528b5fa-d056-4015-9d6b-730f8cd1f6e1_http result, different first party: null unsupported: false passed: true test failed: 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: f0d481b6-9a56-40f3-91f8-40e1ebcc664a_http result, different first party: null unsupported: false passed: true test failed: false
  write: async (secret) => { // Request a page that will send an HTTPOnly 'set-cookie' response header with secret value. await fetch(`${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: c31d3992-0ff0-4221-85c3-cb903982c96f_http result, different first party: null unsupported: false passed: true test failed: 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(`${baseURI}headers`); let cookie = (await response.json())["cookie"]; return cookie ? cookie.match(/secret=([\w-]+)/)[1]: null; } result, same first party: 44a00af5-7bef-4c52-88aa-059c77acb0ea_http result, different first party: null unsupported: false passed: true test failed: false
cookie (JS)The cookie, first introduced by Netscape in 1994, is a small amount of data stored by your browser on a website's behalf. It has legitimate uses, but it is also the classic cross-site tracking mechanism, and today still the most popular method of tracking users across websites. Browsers can stop cookies from being used for cross-site tracking by either blocking or partitioning them.
  write: (secret) => { document.cookie = `secret=${secret}_js; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 8d4c3b04-1c9c-4118-ab88-18d8216c0933_js result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => { document.cookie = `secret=${secret}_js; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf_js result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => { document.cookie = `secret=${secret}_js; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 07383e38-6a64-45a4-9d54-44460860e159_js result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => { document.cookie = `secret=${secret}_js; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 1bde12f7-ff50-435c-87f6-c695f99320b4_js result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => { document.cookie = `secret=${secret}_js; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 3ce76e00-7743-4b76-ae2c-f9532935dfa2_js result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => { document.cookie = `secret=${secret}_js; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: d528b5fa-d056-4015-9d6b-730f8cd1f6e1_js result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => { document.cookie = `secret=${secret}_js; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: f0d481b6-9a56-40f3-91f8-40e1ebcc664a_js result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => { document.cookie = `secret=${secret}_js; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: c31d3992-0ff0-4221-85c3-cb903982c96f_js result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => { document.cookie = `secret=${secret}_js; SameSite=None; Secure`; } read: () => document.cookie ? document.cookie.match(/secret=([\w-]+)/)[1] : null result, same first party: 44a00af5-7bef-4c52-88aa-059c77acb0ea_js result, different first party: null unsupported: false passed: true test failed: 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 result, different first party: Error: Unsupported unsupported: true passed: undefined test failed: 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 result, different first party: Error: Unsupported unsupported: true passed: undefined test failed: 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 result, different first party: Error: Unsupported unsupported: true passed: undefined test failed: 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 result, different first party: Error: Unsupported unsupported: true passed: undefined test failed: 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 result, different first party: Error: Unsupported unsupported: true passed: undefined test failed: 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 result, different first party: Error: Unsupported unsupported: true passed: undefined test failed: 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 result, different first party: Error: Unsupported unsupported: true passed: undefined test failed: 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 result, different first party: Error: Unsupported unsupported: true passed: undefined test failed: 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 result, different first party: Error: Unsupported unsupported: true passed: undefined test failed: 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_09309708742237022 result, different first party: fake_9466138666043957 unsupported: false passed: true test failed: 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_49669587620072964 result, different first party: fake_5762828723519888 unsupported: false passed: true test failed: 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_41685194485536203 result, different first party: fake_5381522258532108 unsupported: false passed: true test failed: 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_7521566186625301 result, different first party: fake_2482400738442041 unsupported: false passed: true test failed: 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_001855967836119632 result, different first party: fake_009762844416080885 unsupported: false passed: true test failed: 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_3534109299439896 result, different first party: fake_5396808961536681 unsupported: false passed: true test failed: 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_19537177957155838 result, different first party: fake_559862166910319 unsupported: false passed: true test failed: 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_9948710424993981 result, different first party: fake_7595876379221447 unsupported: false passed: true test failed: 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_6432805303016156 result, different first party: fake_18988356043354182 unsupported: false passed: true test failed: 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(500); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1 result, different first party: 1 unsupported: false passed: false test failed: false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(500); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1 result, different first party: 1 unsupported: false passed: false test failed: false
write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(500); 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(500); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1 result, different first party: 1 unsupported: false passed: false test failed: false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(500); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1 result, different first party: 1 unsupported: false passed: false test failed: false
write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(500); 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(500); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1 result, different first party: 1 unsupported: false passed: false test failed: false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(500); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1 result, different first party: 2 unsupported: false passed: true test failed: false
  write: (key) => key read: async (key) => { // Wait for the favicon to load (defined in supercookies.html) await sleepMs(500); let response = await fetch( testURI("ctr", "favicon", key), {"cache": "reload"}); let count = (await response.text()).trim(); if (count === "0") { throw new Error("No requests received"); } return count; } result, same first party: 1 result, different first party: 1 unsupported: false passed: false test failed: false
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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 3 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); await sleepMs(500); let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2 result, different first party: 3 unsupported: false passed: true test failed: 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("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); await sleepMs(500); let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2 result, different first party: 3 unsupported: false passed: true test failed: 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("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); await sleepMs(500); let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1 result, different first party: 2 unsupported: false passed: true test failed: false
  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("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); await sleepMs(500); let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2 result, different first party: 3 unsupported: false passed: true test failed: 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("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); await sleepMs(500); let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2 result, different first party: 3 unsupported: false passed: true test failed: 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("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); await sleepMs(500); let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2 result, different first party: 3 unsupported: false passed: true test failed: 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("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); await sleepMs(500); let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2 result, different first party: 3 unsupported: false passed: true test failed: 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("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); await sleepMs(500); let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2 result, different first party: 3 unsupported: false passed: true test failed: 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("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); return key; } read: async (key) => { let style = document.createElement("style"); style.type='text/css'; let fontURI = testURI("resource", "font", key); style.innerHTML = `@font-face {font-family: "myFont"; src: url("${fontURI}"); } body { font-family: "myFont" }`; document.getElementsByTagName("head")[0].appendChild(style); await sleepMs(500); let response = await fetch( testURI("ctr", "font", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 2 result, different first party: 3 unsupported: false passed: true test failed: 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 unsupported: true passed: undefined test failed: 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 unsupported: true passed: undefined test failed: 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 unsupported: true passed: undefined test failed: 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 unsupported: true passed: undefined test failed: 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 unsupported: true passed: undefined test failed: 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 result, different first party: Error: Unsupported unsupported: true passed: undefined test failed: 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 unsupported: true passed: undefined test failed: 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 unsupported: true passed: undefined test failed: 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 unsupported: true passed: undefined test failed: 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=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 8d4c3b04-1c9c-4118-ab88-18d8216c0933 result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 07383e38-6a64-45a4-9d54-44460860e159 result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: 1bde12f7-ff50-435c-87f6-c695f99320b4 result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 3ce76e00-7743-4b76-ae2c-f9532935dfa2 result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: d528b5fa-d056-4015-9d6b-730f8cd1f6e1 result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: f0d481b6-9a56-40f3-91f8-40e1ebcc664a result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${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: c31d3992-0ff0-4221-85c3-cb903982c96f result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h1.privacytests2.org:8901/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h1.privacytests2.org:8901/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: unsupported: false passed: true test failed: false
H2 connectionHTTP/2 is a web connection protocol introduced in 2015. Some browsers re-use HTTP/2 connections across websites and can thus be used to track users.
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: 8d4c3b04-1c9c-4118-ab88-18d8216c0933 result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: 07383e38-6a64-45a4-9d54-44460860e159 result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: 1bde12f7-ff50-435c-87f6-c695f99320b4 result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: 3ce76e00-7743-4b76-ae2c-f9532935dfa2 result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: d528b5fa-d056-4015-9d6b-730f8cd1f6e1 result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: f0d481b6-9a56-40f3-91f8-40e1ebcc664a result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${secret}`, {cache: "no-store"}); } read: async () => { let response = await fetch(`https://h2.privacytests2.org:8902/?mode=read`, {cache: "no-store"}); return await response.text(); } result, same first party: c31d3992-0ff0-4221-85c3-cb903982c96f result, different first party: unsupported: false passed: true test failed: false
  write: async (secret) => { await fetch(`https://h2.privacytests2.org:8902/?mode=write&secret=${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: 44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: unsupported: false passed: true test failed: false
H3 connectionHTTP/3 is a new standard HTTP connection protocol, still in draft but widely supported by browsers. If it is not partitioned, it can be used to track users across websites.
write: async (secret) => { // Ensure that we can switch over to h3 via alt-svc: for (let i = 0; i<3; ++i) { await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); await sleepMs(500); } // Are we now connecting over h3? let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`, {cache: "no-store"}); let text = await response.text(); // Empty response text indicates we are not connecting over h3: if (text.trim() === "") { throw new Error("Unsupported"); } } read: async () => { let response = await fetch(`https://h3.privacytests2.org:4434/connection_id`); return await response.text(); } result, same first party: result, different first party: 27ee5226ecb045f89a83f847e90dde59 unsupported: true passed: undefined test failed: 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: 99063429a66dedf56334c2488a6f3dd1 result, different first party: 0a4e3d3f781e6a4f56455cff04510653 unsupported: false passed: true test failed: 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: 0360d655df7138dcc313c79d77b0a86f result, different first party: 06acf42b3b6066dfc4c2c61ea5c31b06 unsupported: false passed: true test failed: 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: a89657b2426034f11f20ea7855c15873 result, different first party: 5724cfb23d311937ff83da98e29f9a7d unsupported: false passed: true test failed: 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: 050fb61d67abdc3f7a59078e63953901 result, different first party: 54a08677d207a5d0f75b8bddeda39083 unsupported: false passed: true test failed: 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 passed: undefined test failed: 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: c2865befb457744bf767af74eac4f7de result, different first party: a2bc2e53c7aa4cf821d4ceda9a637bf9 unsupported: false passed: true test failed: 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: e4430c37ba404b099dc70c25dd3ece04 result, different first party: unsupported: false passed: true test failed: 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 passed: undefined test failed: 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 result, different first party: Used http unsupported: false passed: true test failed: false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested result, different first party: Used http unsupported: false passed: true test failed: false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested result, different first party: Used http unsupported: false passed: true test failed: false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested result, different first party: Used http unsupported: false passed: true test failed: false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested result, different first party: Used http unsupported: false passed: true test failed: false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested result, different first party: Used http unsupported: false passed: true test failed: false
  write: set HSTS flag read: read HSTS flag result, same first party: not tested result, different first party: Used http unsupported: false passed: true test failed: false
  write: undefined read: undefined result, same first party: undefined result, different first party: undefined unsupported: undefined passed: undefined test failed: undefined
  write: set HSTS flag read: read HSTS flag result, same first party: not tested result, different first party: Used http unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 3 unsupported: false passed: true test failed: 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 result, different first party: 3 unsupported: false passed: true test failed: false
  write: (key) => new Promise((resolve, reject) => { let img = document.createElement("img"); document.body.appendChild(img); img.addEventListener("load", () => resolve(key), {once: true}); img.src = testURI("resource", "image", key); }) read: async (key) => { let img = document.createElement("img"); document.body.appendChild(img); let imgLoadPromise = new Promise((resolve, reject) => { img.addEventListener("load", resolve, {once: true}); }); img.src = testURI("resource", "image", key); await imgLoadPromise; let response = await fetch( testURI("ctr", "image", key), {"cache": "reload"}); return (await response.text()).trim(); } result, same first party: 1 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 3 unsupported: false passed: true test failed: 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 result, different first party: 3 unsupported: false passed: true test failed: 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 result, different first party: 3 unsupported: false passed: true test failed: 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 result, different first party: 3 unsupported: false passed: true test failed: 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 result, different first party: 3 unsupported: false passed: true test failed: 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 result, different first party: 3 unsupported: false passed: true test failed: 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: 8d4c3b04-1c9c-4118-ab88-18d8216c0933 result, different first party: undefined unsupported: false passed: true test failed: 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: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf result, different first party: undefined unsupported: false passed: true test failed: 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: 07383e38-6a64-45a4-9d54-44460860e159 result, different first party: undefined unsupported: false passed: true test failed: 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: 1bde12f7-ff50-435c-87f6-c695f99320b4 result, different first party: undefined unsupported: false passed: true test failed: 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: 3ce76e00-7743-4b76-ae2c-f9532935dfa2 result, different first party: undefined unsupported: false passed: true test failed: 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: d528b5fa-d056-4015-9d6b-730f8cd1f6e1 result, different first party: undefined unsupported: false passed: true test failed: 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: f0d481b6-9a56-40f3-91f8-40e1ebcc664a result, different first party: undefined unsupported: false passed: true test failed: 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: c31d3992-0ff0-4221-85c3-cb903982c96f result, different first party: undefined unsupported: false passed: true test failed: 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: 44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: undefined unsupported: false passed: true test failed: 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: 8d4c3b04-1c9c-4118-ab88-18d8216c0933 result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 07383e38-6a64-45a4-9d54-44460860e159 result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 1bde12f7-ff50-435c-87f6-c695f99320b4 result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 3ce76e00-7743-4b76-ae2c-f9532935dfa2 result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: d528b5fa-d056-4015-9d6b-730f8cd1f6e1 result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: f0d481b6-9a56-40f3-91f8-40e1ebcc664a result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: c31d3992-0ff0-4221-85c3-cb903982c96f result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => localStorage.setItem("secret", secret) read: () => localStorage.getItem("secret") result, same first party: 44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: null unsupported: false passed: true test failed: 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: 8d4c3b04-1c9c-4118-ab88-18d8216c0933 result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false passed: true test failed: 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: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false passed: true test failed: 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: 07383e38-6a64-45a4-9d54-44460860e159 result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false passed: true test failed: 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: 1bde12f7-ff50-435c-87f6-c695f99320b4 result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false passed: true test failed: 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: 3ce76e00-7743-4b76-ae2c-f9532935dfa2 result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false passed: true test failed: 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') result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false passed: undefined test failed: 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: f0d481b6-9a56-40f3-91f8-40e1ebcc664a result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false passed: true test failed: 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: c31d3992-0ff0-4221-85c3-cb903982c96f result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false passed: true test failed: 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: 44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: Error: undefined is not an object (evaluating 'queryResult.held[0].name') unsupported: false passed: true test failed: 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: 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 result, different first party: Error: No requests received unsupported: true passed: undefined test failed: 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=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: result, different first party: unsupported: false passed: undefined test failed: true
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${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 passed: undefined test failed: 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=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: 07383e38-6a64-45a4-9d54-44460860e159 result, different first party: unsupported: false passed: true test failed: false
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: result, different first party: unsupported: false passed: undefined test failed: 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=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: result, different first party: unsupported: false passed: undefined test failed: true
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${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 passed: undefined test failed: 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=${key}`); } read: async () => { console.log("trying to register the serviceworker now..."); const registration = await Promise.race([ navigator.serviceWorker.register('serviceWorker.js'), sleepMs(500) ]); if (registration === undefined) { // We timed out or otherwise failed. throw new Error("ServiceWorker registration failed"); } console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); let response = await fetch("serviceworker-read"); return await response.text(); } result, same first party: result, different first party: unsupported: false passed: undefined test failed: true
  write: async (key) => { if (!navigator.serviceWorker) { throw new Error("Unsupported"); } let registration = await navigator.serviceWorker.register( 'serviceWorker.js'); console.log(registration); await navigator.serviceWorker.ready; console.log("service worker ready"); await sleepMs(100); await fetch(`serviceworker-write?secret=${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 passed: undefined test failed: 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 passed: undefined test failed: 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"); return messagePromise; } result, same first party: 8d4c3b04-1c9c-4118-ab88-18d8216c0933 result, different first party: none unsupported: false passed: true test failed: 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"); return messagePromise; } result, same first party: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf result, different first party: none unsupported: false passed: true test failed: 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"); return messagePromise; } result, same first party: 07383e38-6a64-45a4-9d54-44460860e159 result, different first party: none unsupported: false passed: true test failed: 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"); return messagePromise; } result, same first party: 1bde12f7-ff50-435c-87f6-c695f99320b4 result, different first party: none unsupported: false passed: true test failed: 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"); return messagePromise; } result, same first party: 3ce76e00-7743-4b76-ae2c-f9532935dfa2 result, different first party: none unsupported: false passed: true test failed: 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"); return messagePromise; } result, same first party: none result, different first party: none unsupported: false passed: false test failed: 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"); return messagePromise; } result, same first party: f0d481b6-9a56-40f3-91f8-40e1ebcc664a result, different first party: none unsupported: false passed: true test failed: 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"); return messagePromise; } result, same first party: c31d3992-0ff0-4221-85c3-cb903982c96f result, different first party: none unsupported: false passed: true test failed: 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"); return messagePromise; } result, same first party: 44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: none unsupported: false passed: true test failed: 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: 380c02bd3552688e060c76b17fe062a49c7f3ae1ccea79e310444175fe9049ce result, different first party: ceed8fad7662135f85df2a5630eb7b6197ba01cfd32c8adf92fe17f435f29b8b unsupported: false passed: true test failed: 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: e5725a679b53a1790f7cb7e6761c52948b34070e672f65ea76d22b364397c75b result, different first party: 9842da668a693ab0d3cb977093f36a1bb339ad68b74524380d5e540f6428b03a unsupported: false passed: true test failed: 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: 35267e9b678e7c65bcda92caf344ca5f2de1469d5993bc8d0ae92d09e16c2a79 result, different first party: 65415036747d0895acdd3c975253cfbdc4d551dece9f43059211d56eb58192bc unsupported: false passed: true test failed: 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: 6812a3595ea6c05b3286b2775f147dd28f0872baa084755f5336013281f632e5 result, different first party: a4913bcc4d1101e2091178d0ec145fc568af205c764cd8e7e7be8c628f5834ea unsupported: false passed: true test failed: 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: 716ff90089c0486a652adb04ae182903b46dc3420f96829d548d6ae70173a9a0 result, different first party: d6ea8c0522f2925befc79da1b5b8f6ea7e141da826f93e286f9395140fac7c3b unsupported: false passed: true test failed: 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: 0d3e7adf26ae6600bf7923417a2e3e021435e0767f7aa0d1dce1be5fc80dd466 result, different first party: 58147e3e3e50f8b358809e00a7c53e63a8cbbe01f8a23e97017608f84903a9ca unsupported: false passed: true test failed: 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: d895636f41119e0fb5cc0ffe88a7ba7fb399a9dbf01d6b7ae1b3dc966c579af9 result, different first party: 2f56edd01bbdd4180e0623c2560aea5635aa2e3ff2c279554e3534d27eeced45 unsupported: false passed: true test failed: 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: 9c79a7040b081ac64a3d6943e996705ee88d9f712aae55b4cf05f0cf9ee0d4d3 result, different first party: f71f6f09e0c798f3c820a7b03d35977aa3574194bcba98e6286c614f7d4ff257 unsupported: false passed: true test failed: 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: 6102b4b52644ae4872922a5bbd39755f28407e97cddec359068d3c0735f53e46 result, different first party: 6fb5f68cbb96e4e42bb911771d1700d4e525914098b2da6f680fcfe7b7d91989 unsupported: false passed: true test failed: 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 result, different first party: Error: Web SQL is deprecated unsupported: false passed: undefined test failed: 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 result, different first party: Error: Web SQL is deprecated unsupported: false passed: undefined test failed: 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 result, different first party: Error: Web SQL is deprecated unsupported: false passed: undefined test failed: 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 result, different first party: Error: Web SQL is deprecated unsupported: false passed: undefined test failed: 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 result, different first party: Error: Web SQL is deprecated unsupported: false passed: undefined test failed: 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 result, different first party: Error: Web SQL is deprecated unsupported: false passed: undefined test failed: 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 result, different first party: Error: Web SQL is deprecated unsupported: false passed: undefined test failed: 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 result, different first party: Error: Web SQL is deprecated unsupported: false passed: undefined test failed: 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 result, different first party: Error: Web SQL is deprecated unsupported: false passed: undefined test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: 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 result, different first party: 2 unsupported: false passed: true test failed: false
Navigation testsWhen 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/ result, different first party: https://test-pages.privacytests2.org/ unsupported: false passed: false test failed: false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/ unsupported: false passed: false test failed: false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/ unsupported: false passed: false test failed: false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/ unsupported: false passed: false test failed: false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/ unsupported: false passed: false test failed: false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/ unsupported: false passed: false test failed: false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/ unsupported: false passed: false test failed: false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/ unsupported: false passed: false test failed: false
  write: (secret) => { /* do nothing */ } read: () => document.referrer result, same first party: https://test-pages.privacytests2.org/ result, different first party: https://test-pages.privacytests2.org/ unsupported: false passed: false test failed: false
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: 8d4c3b04-1c9c-4118-ab88-18d8216c0933 result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: f6dd7acc-80dd-4194-abc3-a9277dfe7eaf result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 07383e38-6a64-45a4-9d54-44460860e159 result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 1bde12f7-ff50-435c-87f6-c695f99320b4 result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 3ce76e00-7743-4b76-ae2c-f9532935dfa2 result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: d528b5fa-d056-4015-9d6b-730f8cd1f6e1 result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: f0d481b6-9a56-40f3-91f8-40e1ebcc664a result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: c31d3992-0ff0-4221-85c3-cb903982c96f result, different first party: null unsupported: false passed: true test failed: false
  write: (secret) => sessionStorage.setItem("secret", secret) read: () => sessionStorage.getItem("secret") result, same first party: 44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: null unsupported: false passed: true test failed: 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_8d4c3b04-1c9c-4118-ab88-18d8216c0933 result, different first party: unsupported: false passed: true test failed: false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_f6dd7acc-80dd-4194-abc3-a9277dfe7eaf result, different first party: unsupported: false passed: true test failed: false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_07383e38-6a64-45a4-9d54-44460860e159 result, different first party: unsupported: false passed: true test failed: false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_1bde12f7-ff50-435c-87f6-c695f99320b4 result, different first party: unsupported: false passed: true test failed: false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_3ce76e00-7743-4b76-ae2c-f9532935dfa2 result, different first party: unsupported: false passed: true test failed: false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_d528b5fa-d056-4015-9d6b-730f8cd1f6e1 result, different first party: unsupported: false passed: true test failed: false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_f0d481b6-9a56-40f3-91f8-40e1ebcc664a result, different first party: unsupported: false passed: true test failed: false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_c31d3992-0ff0-4221-85c3-cb903982c96f result, different first party: unsupported: false passed: true test failed: false
  write: (secret) => window.name = "name_" + secret read: () => window.name result, same first party: name_44a00af5-7bef-4c52-88aa-059c77acb0ea result, different first party: unsupported: false passed: true test failed: false
HTTPS testsHTTPS 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 result: Insecure website loaded
  passed: false result: Insecure website loaded
  passed: false result: Insecure website loaded
  passed: false result: Insecure website loaded
  passed: false result: Insecure website loaded
  passed: false result: Insecure website loaded
  passed: false result: Insecure website loaded
  passed: false result: Insecure website loaded
  passed: false result: 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 passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: 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 passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
  upgraded: false passed: false
Upgradable imageChecks to see if the browser attempts to upgrade an insecure address for an image to HTTPS whenever possible.
  passed: false result: loaded insecurely
  passed: false result: loaded insecurely
  passed: false result: loaded insecurely
  passed: false result: loaded insecurely
  passed: false result: loaded insecurely
  passed: false result: loaded insecurely
  passed: false result: loaded insecurely
  passed: false result: loaded insecurely
  passed: false result: loaded insecurely
Upgradable scriptChecks to see if the browser attempts to upgrade an insecure address for an script to HTTPS whenever possible.
  passed: true result: blocked
  passed: true result: blocked
  passed: true result: blocked
  passed: true result: blocked
  passed: true result: blocked
  passed: true result: blocked
  passed: true result: blocked
  passed: true result: blocked
  passed: true result: blocked
Misc testsThis category includes tests for the presence of miscellaneous privacy features.
GPC enabled first-partyThe Global Privacy Control is an HTTP header that can be sent by a browser to instruct a website not to sell the user's personal data to third parties. This test checks to see if the GPC header is sent by default to the top-level website.
  header value: undefined passed: false
  header value: undefined passed: false
  header value: undefined passed: false
  header value: undefined passed: false
  header value: undefined passed: false
  header value: undefined passed: false
  header value: undefined passed: false
  header value: undefined passed: false
  header value: undefined passed: 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
  passed: false
  passed: false
  passed: false
  passed: false
  passed: false
  passed: false
  passed: false
  passed: 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
  passed: false
  passed: false
  passed: false
  passed: false
  passed: false
  passed: false
  passed: false
  passed: 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 readSameFirstParty: Error: Unsupported readDifferentFirstParty: Error: Unsupported testFailed: false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true readSameFirstParty: Error: Unsupported readDifferentFirstParty: Error: Unsupported testFailed: false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true readSameFirstParty: Error: Unsupported readDifferentFirstParty: Error: Unsupported testFailed: false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true readSameFirstParty: Error: Unsupported readDifferentFirstParty: Error: Unsupported testFailed: false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true readSameFirstParty: Error: Unsupported readDifferentFirstParty: Error: Unsupported testFailed: false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true readSameFirstParty: Error: Unsupported readDifferentFirstParty: Error: Unsupported testFailed: false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true readSameFirstParty: Error: Unsupported readDifferentFirstParty: Error: Unsupported testFailed: false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true readSameFirstParty: Error: Unsupported readDifferentFirstParty: Error: Unsupported testFailed: false
write: () => { if (!usingTor) { throw new Error("Unsupported"); } } read: async () => { if (usingTor) { return ipAddress; } else { throw new Error("Unsupported"); } } unsupported: true readSameFirstParty: Error: Unsupported readDifferentFirstParty: Error: Unsupported testFailed: false
Tor 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 passed: false
  IsTorExit: false passed: false
  IsTorExit: false passed: false
  IsTorExit: false passed: false
  IsTorExit: false passed: false
  IsTorExit: false passed: false
  IsTorExit: false passed: false
  IsTorExit: false passed: false
  IsTorExit: false passed: false
Fingerprinting resistance testsFingerprinting 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 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 667 desired value: undefined passed: false
Media query screen widthWidth of the user's screen in pixels.
  expression: undefined desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: undefined desired expression: undefined actual value: 375 desired value: undefined passed: false
outerHeightHeight of the browser window in pixels, including browser chrome.
  expression: outerHeight desired expression: undefined actual value: 553 desired value: undefined passed: false
  expression: outerHeight desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: outerHeight desired expression: undefined actual value: 546 desired value: undefined passed: false
  expression: outerHeight desired expression: undefined actual value: 556 desired value: undefined passed: false
  expression: outerHeight desired expression: undefined actual value: 547 desired value: undefined passed: false
  expression: outerHeight desired expression: undefined actual value: 547 desired value: undefined passed: false
  expression: outerHeight desired expression: undefined actual value: 555 desired value: undefined passed: false
  expression: outerHeight desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: outerHeight desired expression: undefined actual value: 667 desired value: undefined passed: false
screen.heightHeight of the user's screen, in pixels.
  expression: screen.height desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: screen.height desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: screen.height desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: screen.height desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: screen.height desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: screen.height desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: screen.height desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: screen.height desired expression: undefined actual value: 667 desired value: undefined passed: false
  expression: screen.height desired expression: undefined actual value: 667 desired value: undefined passed: false
screen.widthWidth of the user's screen, in pixels.
  expression: screen.width desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: screen.width desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: screen.width desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: screen.width desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: screen.width desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: screen.width desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: screen.width desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: screen.width desired expression: undefined actual value: 375 desired value: undefined passed: false
  expression: screen.width desired expression: undefined actual value: 375 desired value: undefined passed: false
screenXPosition, in pixels, of the left edge of the browser window on screen.
  expression: screenX desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenX desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenX desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenX desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenX desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenX desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenX desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenX desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenX desired expression: undefined actual value: 0 desired value: undefined passed: true
screenYPosition, in pixels, of the top edge of the browser window on screen.
  expression: screenY desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenY desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenY desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenY desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenY desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenY desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenY desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenY desired expression: undefined actual value: 0 desired value: undefined passed: true
  expression: screenY desired expression: undefined actual value: 0 desired value: undefined passed: true
Tracking query parameter testsWhen 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
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
__hsscHubSpot tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
__hstcHubSpot tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
__sDrip.com email address tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
_hsencHubSpot tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
_openstatYandex tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
dclidDoubleClick Click ID (Google)
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
fbclidFacebook Click Identifier
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  passed: true
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
gclidGoogle Click Identifier
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  passed: true
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
hsCtaTrackingHubSpot tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
igshidInstagram tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
mc_eidMailchimp Email ID (email recipient's address)
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
mkt_tokAdobe Marketo tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  passed: true
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
ml_subscriberMailerLite email tracking
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
ml_subscriber_hashMailerLite email tracking
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
msclkidMicrosoft Click ID
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
oly_anon_idOmeda marketing 'anonymous' customer id
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
oly_enc_idOmeda marketing 'known' customer id
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
rb_clickidUnknown high-entropy tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
s_cidAdobe Site Catalyst tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
vero_convVero tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
vero_idVero tracking parameter
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
wickedidWicked Reports e-commerce tracking
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
yclidYandex Click ID
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
  value: 9418781819456175 passed: false
Tracker content blockingWhen 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
  url: https://munchkin.marketo.net/munchkin.js passed: false
  url: https://munchkin.marketo.net/munchkin.js passed: true
  url: https://munchkin.marketo.net/munchkin.js passed: false
  url: https://munchkin.marketo.net/munchkin.js passed: false
  url: https://munchkin.marketo.net/munchkin.js passed: true
  url: https://munchkin.marketo.net/munchkin.js passed: false
  url: https://munchkin.marketo.net/munchkin.js passed: false
  url: https://munchkin.marketo.net/munchkin.js passed: 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
  url: https://dpm.demdex.net/ibs passed: false
  url: https://dpm.demdex.net/ibs passed: true
  url: https://dpm.demdex.net/ibs passed: false
  url: https://dpm.demdex.net/ibs passed: false
  url: https://dpm.demdex.net/ibs passed: true
  url: https://dpm.demdex.net/ibs passed: false
  url: https://dpm.demdex.net/ibs passed: false
  url: https://dpm.demdex.net/ibs passed: 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
  url: https://s.amazon-adsystem.com/dcm passed: false
  url: https://s.amazon-adsystem.com/dcm passed: true
  url: https://s.amazon-adsystem.com/dcm passed: false
  url: https://s.amazon-adsystem.com/dcm passed: false
  url: https://s.amazon-adsystem.com/dcm passed: true
  url: https://s.amazon-adsystem.com/dcm passed: false
  url: https://s.amazon-adsystem.com/dcm passed: false
  url: https://s.amazon-adsystem.com/dcm passed: 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
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: true
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: true
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: false
  url: https://ib.adnxs.com/px?id=178248&t=1 passed: 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
  url: https://bat.bing.com/bat.js passed: false
  url: https://bat.bing.com/bat.js passed: true
  url: https://bat.bing.com/bat.js passed: false
  url: https://bat.bing.com/bat.js passed: false
  url: https://bat.bing.com/bat.js passed: false
  url: https://bat.bing.com/bat.js passed: false
  url: https://bat.bing.com/bat.js passed: false
  url: https://bat.bing.com/bat.js passed: 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
  url: https://static.chartbeat.com/js/chartbeat.js passed: false
  url: https://static.chartbeat.com/js/chartbeat.js passed: true
  url: https://static.chartbeat.com/js/chartbeat.js passed: false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false
  url: https://static.chartbeat.com/js/chartbeat.js passed: true
  url: https://static.chartbeat.com/js/chartbeat.js passed: false
  url: https://static.chartbeat.com/js/chartbeat.js passed: false
  url: https://static.chartbeat.com/js/chartbeat.js passed: 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
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: true
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: true
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false
  url: https://dis.criteo.com/dis/rtb/appnexus/cookiematch.aspx passed: false
DoubleClick (Google)Tests whether the browser blocks the page from loading the tracker at https://securepubads.g.doubleclick.net/static/glade.js
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: true
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: true
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: true
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: false
  url: https://securepubads.g.doubleclick.net/static/glade.js passed: 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
  url: https://connect.facebook.net/en_US/fbevents.js passed: false
  url: https://connect.facebook.net/en_US/fbevents.js passed: true
  url: https://connect.facebook.net/en_US/fbevents.js passed: false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false
  url: https://connect.facebook.net/en_US/fbevents.js passed: true
  url: https://connect.facebook.net/en_US/fbevents.js passed: false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false
  url: https://connect.facebook.net/en_US/fbevents.js passed: false
Google (third-party ad pixel)Tests whether the browser blocks the page from loading the tracker at https://www.google.com/pagead/1p-user-list/
  url: https://www.google.com/pagead/1p-user-list/ passed: true
  url: https://www.google.com/pagead/1p-user-list/ passed: false
  url: https://www.google.com/pagead/1p-user-list/ passed: true
  url: https://www.google.com/pagead/1p-user-list/ passed: false
  url: https://www.google.com/pagead/1p-user-list/ passed: false
  url: https://www.google.com/pagead/1p-user-list/ passed: false
  url: https://www.google.com/pagead/1p-user-list/ passed: false
  url: https://www.google.com/pagead/1p-user-list/ passed: false
  url: https://www.google.com/pagead/1p-user-list/ passed: 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
  url: https://google-analytics.com/urchin.js passed: false
  url: https://google-analytics.com/urchin.js passed: true
  url: https://google-analytics.com/urchin.js passed: false
  url: https://google-analytics.com/urchin.js passed: false
  url: https://google-analytics.com/urchin.js passed: true
  url: https://google-analytics.com/urchin.js passed: false
  url: https://google-analytics.com/urchin.js passed: false
  url: https://google-analytics.com/urchin.js passed: 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
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: true
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: false
  url: https://www.googletagmanager.com/gtag.js?id=GTM-NX4SMZL passed: 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
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: true
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: true
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: false
  url: https://dsum-sec.casalemedia.com/crum?cm_dsp_id=10&external_user_id=629685505537&C=1 passed: 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
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: true
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: true
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: false
  url: https://js-agent.newrelic.com/nr-1212.min.js passed: 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
  url: https://pixel.quantserve.com/pixel passed: false
  url: https://pixel.quantserve.com/pixel passed: true
  url: https://pixel.quantserve.com/pixel passed: false
  url: https://pixel.quantserve.com/pixel passed: false
  url: https://pixel.quantserve.com/pixel passed: true
  url: https://pixel.quantserve.com/pixel passed: false
  url: https://pixel.quantserve.com/pixel passed: false
  url: https://pixel.quantserve.com/pixel passed: 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
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: true
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: true
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: false
  url: https://sb.scorecardresearch.com/internal-c2/default/cs.js passed: 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
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: true
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: true
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: false
  url: https://trc.taboola.com/futureplc-tomsguide/trc/3/json passed: 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
  url: https://t.co/i/adsct passed: false
  url: https://t.co/i/adsct passed: true
  url: https://t.co/i/adsct passed: false
  url: https://t.co/i/adsct passed: false
  url: https://t.co/i/adsct passed: false
  url: https://t.co/i/adsct passed: false
  url: https://t.co/i/adsct passed: false
  url: https://t.co/i/adsct passed: 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
  url: https://yandex.ru/ads/system/header-bidding.js passed: false
  url: https://yandex.ru/ads/system/header-bidding.js passed: true
  url: https://yandex.ru/ads/system/header-bidding.js passed: false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false
  url: https://yandex.ru/ads/system/header-bidding.js passed: false