What is a browser fingerprint?
A browser fingerprint combines dozens of settings and rendering quirks into an identifier that can persist even when your IP changes. Learn how it works.
How fingerprinting works
Every browser exposes details to the pages it loads: screen size, time zone, languages, installed fonts, graphics hardware, and how it renders text and shapes. Individually these are common. Combined, they can be distinctive enough to recognise the same browser on a later visit.
Unlike a cookie, a fingerprint is not stored on your device. It is recomputed each time, so clearing cookies does not reset it.
What it is not
A browser fingerprint is not a hardware serial number and not a guaranteed device ID. Two identical laptops with the same browser version can produce the same fingerprint, and a browser update can change yours. That is why tools talk about fingerprint similarity and confidence rather than certainty.
IP address vs fingerprint
Your IP describes your network connection. Your fingerprint describes your browser. Switch to a VPN and your IP changes completely while most fingerprint signals stay the same. Websites that care about identity often look at both.
Reducing fingerprintability
Browsers such as Tor Browser, Brave, Firefox with resistFingerprinting, and Safari apply protections that either standardise values (so many users look identical) or add small random noise (so the value differs on every visit). This site labels such values as hidden or randomised when it can detect them.