Browser Fingerprint Audit

Browser Fingerprint Audit

Run this audit and read 27 details that any website can get from your browser without asking: your browser and version, screen, time zone, graphics card, fonts and more. It shows each one, combines them into a fingerprint, and estimates how much they narrow down who you are. There's nothing to install or click.

What a browser fingerprint is

Cookies are files a site stores in your browser; you can see them, block them and delete them. A fingerprint works without storing anything. A site simply reads how your browser is set up. Each detail on its own is shared by millions of people, but together they often form a combination almost nobody else has. That lets a site recognize you on your next visit even after you've cleared every cookie.

Reading the result

Here's an example result from Chrome on Linux:

What the bits mean. Each bit halves the number of people you could be. 33 bits is enough to tell apart every person on Earth, since 2 to the power of 33 is about 8.6 billion. If every signal were independent, 41.7 bits would make this browser one in about 3.6 trillion.

They aren't independent, and the audit says so. The estimate adds up figures measured for each signal across 118,934 browsers in the AmIUnique study, published in 2016. Signals overlap, though. Knowing the browser runs Linux already tells you a lot about its user agent, for example. So treat the total as an upper estimate, not an exact measurement.

The biggest contributors in this example:

The browser's languages and time zone added about 9 bits more between them.

Signals without a figure. CPU cores, device memory, pixel ratio, the audio fingerprint and installed fonts show no bits because the 2016 study didn't measure them. Trackers use them anyway. So the real picture cuts both ways: overlap pushes the true figure below the estimate, while these unmeasured signals push it back up.

The signals explained

Browser and engine

User agent is the text your browser sends with every request. It scores highest here, but the study was done before browsers froze their version numbers. Chrome's user agent now says 154.0.0.0 instead of the exact build, so today's user agent reveals somewhat less than the 9.8 bits suggest.

Platform confirms the operating system and processor type. Linux on x86 is much rarer on the web than Windows.

Language and time

Languages are your browser's language preferences, in order. A single common language says little. An unusual combination, such as English plus a less widely spoken language, narrows you down quickly.

Time zone comes from your computer's clock, not your IP address, so a VPN doesn't change it.

Display

Screen resolution is distinctive whenever it's anything other than the handful of most common laptop sizes. An ultrawide 3440 × 1440 monitor, scaled to 1.25×, is shared by relatively few browsers.

Hardware

CPU cores counts processor threads. Device memory is rounded by the browser. Touch points shows whether there's a touch screen. Each is common on its own, but they add detail when combined with everything else.

Graphics and media

GPU vendor and renderer name your graphics card through WebGL. A recent, specific model stands out far more than a common built-in laptop chip.

Canvas fingerprint. The page draws hidden text and shapes and reads back the pixels. Tiny differences in graphics hardware, drivers, fonts and anti-aliasing make the result slightly different from machine to machine, and the audit turns it into a short code. It's one of the strongest signals there is.

Audio fingerprint works the same way with sound. A short tone is processed through the browser's audio engine, and minute differences in the output identify the setup.

Installed fonts. The audit checks for 40 common fonts by measuring how text renders, and found 9 in this example. Which fonts you have depends on your operating system and the software you've installed.

Privacy and state

Do Not Track is an awkward case. It's meant to protect your privacy, but so few people turn it on that having it switched on makes your browser more distinctive. Almost every site ignores the request itself.

Global Privacy Control is the newer privacy signal, with legal weight in some US states. "Not exposed" means this browser doesn't send it.

Browser plugins shows 5 for almost everyone. Modern browsers report the same fixed list of five PDF viewer entries instead of real plugins, precisely so this list can no longer identify anyone.

Cookies, local storage and the PDF viewer are on in nearly every browser, which is why they contribute so little.

What doesn't change your fingerprint

Clearing cookies. The fingerprint never lived in a cookie.

Private or incognito mode. In Chrome, an incognito window gives almost exactly the same fingerprint as a normal one.

A VPN. It changes your IP address and nothing on this page. If your VPN address is in another country but your time zone isn't, that mismatch can make you stand out more.

How to make your browser less identifiable

There are two working strategies: look the same as everyone else, or look different every time.

• Tor Browser makes every user look alike, down to standard window sizes, so there's nothing to tell users apart.
• Brave randomizes canvas, audio and similar signals for each site and session. Run this audit twice in Brave and the canvas code should change, which is a good way to confirm the protection is working.
• Firefox blocks known fingerprinting scripts by default. Its stricter privacy.resistFingerprinting setting (in about:config) also reports generic values for things like screen size and time zone, at the cost of breaking some sites.
• Safari includes Advanced Fingerprinting Protection, switched on in Private Browsing by default.

Two cautions. Piling on privacy extensions often backfires, because a rare set of extensions is itself identifying. And fingerprinting isn't only used for advertising: banks and bot-protection services use it to spot fraud. Heavily protected browsers tend to see more CAPTCHAs and extra login checks.

FAQ

Can websites really read all this without asking?

Yes. Every value comes from standard browser features that need no permission. This page only shows you what other sites can quietly collect.

Why did my fingerprint change?

The fingerprint code changes whenever any signal in it changes: a browser update, a new monitor, a different window size or a new font. Real tracking scripts are smarter than a single code, though. They can link your old and new fingerprints because most of the other signals stay the same.

Is fingerprinting legal?

In the EU, privacy rules generally treat fingerprinting like cookies, so sites need your consent to use it for tracking. Elsewhere the rules are looser. In 2025 Google began allowing advertisers on its platforms to use fingerprinting, which it had previously prohibited.

Where can I see the rest of what my browser shares?

What's My Browser shows your full browser details, including your IP address. The WebRTC Leak Test and DNS Leak Tester check whether a VPN is hiding as much as it should.