Browser Fingerprint Test

A browser fingerprint is the combination of small, individually harmless details your browser hands to every website you visit, your screen size, timezone, fonts, graphics card, language settings and dozens more. On their own none of them identify you. Together, they are often unique enough to recognise your browser on a later visit without any cookie at all.

That is the uncomfortable part. Cookies can be cleared and blocked, and increasingly they are. Fingerprinting sidesteps that entirely: it does not store anything on your device, it simply measures what is already there. A tracker builds the same fingerprint on each visit and matches them up. The technique is quiet, needs no permission prompt, and works in private-browsing windows.

The scan above gathers signals from three different layers of the browser, then hashes the whole set into the single ID you see. Each layer is measured the same way commercial fingerprinting libraries measure it.

• Canvas rendering. The page draws hidden text and shapes to a canvas and reads the pixels back. Tiny differences in your GPU, drivers, anti-aliasing and installed fonts change those pixels, so the same drawing produces a slightly different image on different machines.
• WebGL and the GPU. Your graphics hardware reports a vendor and renderer string, and renders 3D test output with machine-specific quirks. The GPU model alone is one of the highest-value signals there is.
• Audio processing. An oscillator is run through the Web Audio engine offline. The maths is deterministic in theory, but small floating-point differences between devices make the output a stable, measurable value.
• Device and browser facts. Screen resolution, pixel ratio, colour depth, CPU cores, memory, timezone, languages, touch support and the list of installed fonts, each narrows the crowd a little further.

Every one of those is combined and passed through a hashing function, so the same browser produces the same ID, and a single changed signal produces a completely different one.

Not every signal carries the same weight. Some, like whether cookies are enabled, split the world into two big halves and barely help a tracker. Others can nearly identify you on their own.

The score above weights each signal roughly by how much it narrows the crowd, which is why turning cookies off changes almost nothing while a rare GPU changes a lot.

The result is shown in bits of entropy. It is the unit privacy researchers use, and it has a simple meaning: each extra bit roughly halves the number of people who share your fingerprint. Ten bits is one in about a thousand; twenty bits is one in a million.

Large studies of real visitors have found the average browser sits around eighteen bits of entropy, enough to single out most people. A phone on default settings usually scores lower and blends into a big crowd; a customised desktop scores higher and stands out.

You cannot remove your fingerprint, the same signals make pages render correctly, but you can make it far less distinctive and far less stable.

• Use a browser that fights fingerprinting. Brave and the Tor Browser randomise or standardise the highest-value signals; Firefox has a resistFingerprinting mode that does the same.
• Keep defaults. A maximised window at a common resolution, the default font set and no exotic tweaks all push you toward the crowd rather than away from it.
• Go easy on extensions. Each niche add-on can leave a trace. A stack of unusual extensions is itself a distinguishing trait.
• Do not rely on a VPN alone. It hides your IP, not your fingerprint. Pair it with a fingerprint-resistant browser if tracking is your concern, and check the WebRTC leak test to be sure your real IP is not leaking anyway.

Test again after each change and watch the bit count fall. When rescanning produces a different ID each time, a tracker can no longer join your visits together, which is the outcome that actually protects you.