How unique is your browser?

What a browser fingerprint is

A browser fingerprint is a profile built from many small facts your browser shares with every site: its version, your screen size, your time zone, your languages, the fonts installed, how your graphics card draws an image and more. None of these identifies you alone, but together they can be rare enough to recognise your browser again without cookies.

This test collects those facts, combines them into a fingerprint ID and shows how much each one contributes. Everything is computed in your browser. Nothing is sent to our server or stored.

What is collected

• Basic details: user agent, platform, languages, time zone, screen size and colour depth.
• Hardware hints: device memory, logical processor count and touch support.
• Settings: whether cookies are enabled and whether Do Not Track or Global Privacy Control is on.
• Canvas and WebGL: a hash of a small drawing, and the graphics vendor and renderer names.
• Audio: a hash of a short sound your browser generates silently.
• Fonts: which of about 30 common fonts are installed, found by measuring text widths.
• Plugins: the list of browser plugins, which is short or empty in modern browsers.

How to read the entropy figures

Entropy is measured in bits. Each bit halves the group of people who look like you, so about 33 bits would single out one person among all 8 billion. The figures shown here are rough, rounded values in the spirit of published studies such as the EFF's Panopticlick and Cover Your Tracks. They are illustrations, not measurements of your browser, and real values change with time and population.

The total is also an overestimate, because attributes are linked: a Mac user agent goes with Mac fonts and a Mac graphics renderer. Treat the number as a sense of scale, not a verdict.

How to reduce fingerprinting

• Tor Browser makes all users look alike, which is the strongest approach, at the cost of speed.
• Firefox with privacy.resistFingerprinting enabled in about:config reports generic values and rounds the screen size. It can break some sites.
• Brave randomises canvas, WebGL and audio output for each session.
• Fewer extensions, fewer unusual fonts and a standard window size all help, because unusual settings make you stand out.

Why sites fingerprint browsers

Fingerprinting is used for fraud prevention, such as spotting a stolen account logging in from an unfamiliar browser, and for bot detection. It is also used for advertising and tracking, because it still works when cookies are blocked or cleared. Unlike a cookie, a fingerprint is not stored on your device, so you cannot delete it.

That is why the useful defence is blending in. A browser that looks like many others is hard to single out, while one with an unusual font list, an odd window size and a rare language setting is easy to recognise.

Related reading

If you are also wondering what people-search sites publish about you, our guide on [how to remove your personal information from the internet](/guides/remove-personal-info-online) covers the free steps.