About
liarjs.dev asks one question: can your browser fool me? I read it in JavaScript, cross-check that against what Cloudflare saw at the network / TLS layer, and then check whether a hand is driving it at all. A browser controls its own JavaScript; it does not control the network it connects over, and it cannot fake a hand on the pointer.
What this is
A single-page diagnostic that scores a browser on three separate axes, because they fail independently. Real browsers are internally coherent: the story the JavaScript tells about your GPU, fonts, audio stack and locale lines up with the story your network connection tells. Spoofed and anti-detect setups leak because keeping every layer in agreement is hard. But a perfectly coherent browser can still be a browser with a program at the wheel, and that is a different question, so I ask it separately.
The project is educational and defensive: it helps you understand what a modern detector can see, and it lets people who work on anti-detect tooling check their own footprint. It is not a service for evading detection, and I don't sell profiles, proxies or bypasses.
How it works
Three axes, scored independently:
- Fingerprint. Canvas, WebGL, WebGPU, audio, fonts,
navigator, screen and WebRTC are read entirely in your browser, then cross-checked against each other. - Network. Cloudflare attaches signals to the request (ASN, colo, TLS version, client-hello shape) via
request.cf, things the page's own JavaScript can never observe about itself. Where the two stories disagree is a finding. - Automation. Is a program driving this browser? Passively, that means
navigator.webdriver, a removedwebdriverproperty and framework residue. Those catch the careless. An unpatched, headed Chrome driven over the DevTools protocol leaves none of them, so the site also offers a behavioural challenge: follow a pointer for a few seconds and I read the coalesced samples, the curvature of the path and the jitter in the event timing. Passing it is what turns a provisional score final. Not taking it costs nothing.
The scan runs live in your browser and at the edge. It's a read-only measurement: nothing about your session is written to a database or shared. See the privacy policy & disclaimer for the details.
Contact
Questions, corrections, takedown requests or press? Email me:
I read everything and reply to what needs a reply.