Browser fingerprint test: what your browser reveals
Websites can recognise you without a single cookie by reading small details about your device and browser. Run the test to see exactly what they can read, and how identifying each detail is. Nothing is sent anywhere: it all happens in your browser.
Reads the same details a fingerprinting script can, right here in your browser. Nothing is sent or saved.
Why fingerprinting matters
Cookies can be blocked, rejected and deleted. A fingerprint can’t, because it isn’t stored on your device: it’s worked out again on every visit from details your browser shares anyway. That makes it the tracking method of choice when people say no to cookies.
It’s common. On the popular UK websites in the Browser Monster Index, more than a third ran scripts that fingerprint visitors’ devices, using techniques like the canvas drawing and audio test on this page.
How to reduce fingerprinting
- Use a browser with fingerprinting protection. Brave randomises several of these details. Firefox blocks known fingerprinting scripts in its Strict tracking protection mode. Safari reduces what it reveals, especially in private browsing.
- Don’t over-customise. Rare fonts, unusual languages and lots of extensions can make you stand out more.
- Reject cookies anyway. In the UK and EU, refusing consent should also cover fingerprinting for ads. Auto-reject banners to make it effortless.
- See who’s doing it. The Browser Monster extension flags sites that run fingerprinting scripts as you browse, and names the company behind them.
Fingerprinting is part of the hidden side of your digital footprint. You can also remove location from your photos and clean tracking off links.
See which sites fingerprint you
Browser Monster spots canvas, WebGL, audio and font fingerprinting on the pages you visit and names the company behind it. Free, and everything stays on your device.
Questions
- What is browser fingerprinting?
- Browser fingerprinting is a way to recognise your browser without cookies. A script reads dozens of small details (your screen, graphics card, fonts, time zone, how your device draws text and processes sound) and combines them into an ID. Because the combination is usually rare, the same ID turns up whenever you visit, even after you clear cookies.
- Is my fingerprint sent anywhere by this test?
- No. The test reads these details in your browser and shows them to you. Nothing is sent to Browser Monster or anyone else, and nothing is saved. Websites that fingerprint you do send the result to their servers, which is the difference.
- How unique is a browser fingerprint?
- Very, for most people. When the Electronic Frontier Foundation studied around half a million browsers in 2010, 84% had a unique fingerprint, and browsers now expose more detail (such as graphics hardware and audio processing) than they did then.
- Does incognito or private mode stop fingerprinting?
- Mostly not. Private windows throw away cookies and history when you close them, but your screen, graphics card, fonts and time zone stay the same, so the fingerprint usually does too. Some browsers, such as Safari and Brave, add protections that change or hide some of these details.
- Does a VPN stop fingerprinting?
- No. A VPN hides your IP address, but fingerprinting doesn’t rely on it. Your time zone and languages can even give away roughly where you really are.
- Is fingerprinting legal?
- In the UK and EU, fingerprinting falls under the same rules as cookies: sites need your consent to use it for advertising. In practice it’s hard to see and hard to refuse. When Google started allowing advertisers to use fingerprinting in February 2025, the UK’s Information Commissioner’s Office called the change “irresponsible”.