Browser Fingerprint Test
Websites can recognise your browser without cookies by combining small details: how it draws graphics, renders audio, which fonts are installed and your screen setup. This test collects the same signals a tracker would, hashes them and estimates how identifying they are. Nothing leaves your device.
computing…
Running tests…
Canvas
…WebGL
…Audio
…An oscillator is rendered silently through a compressor in an offline audio context; the summed output differs slightly between audio stacks.
Fonts
…Screen
…Browser & system
…Entropy by attribute
| Attribute | Your value | Est. bits | Share of total |
|---|
Bits for user agent, fonts, screen, time zone and cookies follow the EFF Panopticlick study (Eckersley, 2010); the others are rough estimates. Attributes overlap, so the total is an upper bound.
Protections detected & privacy tips
How to use the Browser Fingerprint Test
- Open the page: the test runs automatically within a second or two.
- Read your fingerprint ID and the estimated bits of identifying information at the top.
- Check each component: canvas, WebGL, audio, fonts, screen and system values, each with its own hash.
- Look at the protections and tips to see what your browser already hides and what you can change.
- Run the test again in another browser, a private window or with a VPN to compare. Copy or download the report if you need it.
How browser fingerprinting works
A cookie is a label a site stores in your browser. A fingerprint is different: the site stores nothing on your device. It reads many small properties that your browser reveals anyway, combines them and hashes the result into an ID. If enough of those properties are unusual together, the ID points to one browser, even in a private window and after you clear cookies.
| Signal | What is measured | Why it differs between devices |
|---|---|---|
| Canvas | Pixels of text, emoji and shapes drawn on a hidden <canvas> | Font rendering, anti-aliasing, GPU and driver differences |
| WebGL | Graphics vendor and renderer strings, limits, extensions and a rendered 3D image | Graphics card model, driver version, operating system |
| Audio | Output of an oscillator processed by a compressor in an offline audio context | Floating point and audio stack implementation details |
| Fonts | Which fonts change the width of a test string | Installed applications, language packs, design software |
| Screen | Resolution, available area, pixel ratio, colour depth and gamut | Monitor model, scaling setting, taskbar size |
| System | User agent, platform, languages, time zone, CPU threads, memory, touch | Browser version, region and hardware |
What the entropy numbers mean
Entropy, measured in bits, describes how much an attribute narrows down who you are. If a value is shared by 1 in 2n browsers, it carries n bits. Ten bits means about 1 in 1,024; 20 bits about 1 in a million; 33 bits about 1 in 8.6 billion, which is more than the world population. In the EFF's 2010 Panopticlick study of about 470,000 browsers, 83.6% had a unique fingerprint, with fonts (13.9 bits) and the user agent (10.0 bits) among the most identifying attributes.
Real attributes are correlated (a Mac user agent already predicts Mac fonts), so adding the bits overstates the total. Treat the number on this page as an upper-bound estimate of how trackable your setup is, not as an exact uniqueness score.
Randomize or blend in?
- Blend in: the Tor Browser makes every user report the same values (window size, fonts, time zone), so all users look alike.
- Randomize: Brave, and Safari's advanced fingerprinting protection, add small random changes to canvas, audio and other readings per site or session, so the hash never matches twice.
- Block: some extensions block canvas or WebGL reads. This works, but being one of few users who block can itself become a signal.
To compare, run this test in two different browsers, then in a private window. Also check whether your real IP address leaks through WebRTC when using a VPN.
Frequently asked questions
What is browser fingerprinting?
Browser fingerprinting is a tracking technique that identifies a browser by combining many small characteristics, such as the user agent, screen size, time zone, installed fonts and tiny differences in how graphics and audio are rendered. Unlike cookies, nothing is stored on your device, so clearing cookies or using a private window does not change it.
Is this test private?
Yes. Every measurement runs locally in your browser with JavaScript and the results are never uploaded. The only thing saved is your last fingerprint ID in your browser's local storage, so the page can tell you if it changed since your last visit. You can clear it with the button on the page.
What is a canvas fingerprint?
The page draws text, emoji and shapes on a hidden canvas and reads back the pixels. Small differences in graphics hardware, drivers, operating system font rendering and anti-aliasing make the resulting image slightly different between devices, so its hash works as an identifier. Browsers such as Brave, and Firefox with resistFingerprinting, add random noise to stop this.
What does the entropy in bits mean?
Entropy measures how much identifying information an attribute carries. Each extra bit halves the number of people who share your value: 10 bits means roughly 1 in 1,024 browsers share it. About 33 bits are enough to single out one person among 8 billion. The per-attribute numbers here are rough estimates and attributes overlap, so the total is an upper bound, not an exact uniqueness score.
Why does my fingerprint change between visits?
Browser updates, a new graphics driver, installing fonts, changing zoom or screen, connecting a monitor or moving to another time zone all change parts of the fingerprint. Browsers with fingerprint randomization deliberately change the canvas and audio hashes for every site or session, which is good for privacy.
How can I reduce browser fingerprinting?
Use a browser with built-in fingerprinting protection (for example Brave, Firefox with Enhanced Tracking Protection set to strict, or the Tor Browser), keep it updated, avoid installing unusual fonts and extensions, and leave window size and other settings at common defaults. Blending in with many other users is more effective than adding many custom privacy tweaks.
Does a VPN stop browser fingerprinting?
No. A VPN hides your IP address, but the fingerprint is built from your browser and device, which stay the same. A VPN plus a fingerprint-resistant browser gives much better protection than either alone.