Browser fingerprint test
This reads every surface a website can read about your browser and computer — identity, hardware, canvas and WebGL, audio, fonts, voices — and lists the contradictions a detector looks for. It runs the moment the page loads, in your browser. Only the network row comes from the server, and that is just your own request echoed back.
Consistency — the contradictions a scanner reads first.
- readingMeasuring your browser…
We do not compute a “1 in N” uniqueness number — there is no honest population to compare you with. For that, try AmIUnique or the EFF’s Cover Your Tracks.
Nothing is uploaded. Every value except the network row is read and shown in your browser and sent nowhere. The voice-list note compares against Chrome measured on macOS by Mosaic in 2026 (199 voices on branded Chrome, 180 on an unbranded Chromium build).
Many small values, one identifier
No single value here names you. Together they usually do: your exact GPU and driver, the fonts you have installed, how your machine renders a canvas, your screen and audio stack. A tracker hashes the combination and recognises the same machine on its next visit, with no cookie required. See the browser fingerprint and canvas fingerprinting glossary entries for the long version.
The checks are the point
Having an unusual value is a weak signal. Having two values that cannot both be true on one machine is a strong one — a user-agent that says Windows beside client hints that say macOS, a main thread and a web worker that report different hardware, a timezone that does not match your IP. Masking tools that inject JavaScript to change one surface routinely forget another, and that gap is exactly what a consistency scanner reads. Mosaic changes values in C++ inside its own Chromium, so the page, its frames and its workers all read one machine.
- Open the tool. Open the fingerprint test. It reads your browser the moment the page loads — nothing is sent anywhere and nothing is stored.
- Read your surfaces. Each row is one value a site can read: user-agent and client hints, hardware, canvas and WebGL, audio, fonts, voices, and the IP your network shows.
- Look at the consistency checks. The checks say in a sentence where your values disagree — a user-agent that does not match its client hints, a timezone that does not match your IP, a worker that reports a different machine.
What is a browser fingerprint?
The set of values a page can read about your browser and computer — user-agent, screen, GPU, canvas, audio, fonts, timezone, language and more — which together are often distinctive enough to recognise the same machine again without cookies.
Why does the test flag contradictions instead of a uniqueness score?
Because contradictions are what consistency detectors actually read, and we have no population database, so a “1 in N” number would be invented. A user-agent that disagrees with its client hints, or a timezone that disagrees with the IP, is a concrete signal; a made-up score is not.
Why does the test read values again from a worker?
Because a fingerprint spoofed with injected JavaScript often changes the main thread but not a web worker, so the two disagree — exactly the contradiction a scanner looks for. Mosaic changes values in C++ inside its own Chromium, so the page, its frames and its workers all read one machine.
Is anything about my browser uploaded?
Only the network row comes from the server, and that is just your own request being echoed back — the IP and geo your connection already shows us. Everything else is read and shown in your browser and sent nowhere.
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