Browser Fingerprinting.

A stateless tracking technique that identifies a user by combining browser, device, and configuration attributes into a near-unique signature. It belongs to the Privacy & Data Protection category of cybersecurity.

A stateless tracking technique that identifies a user by combining browser, device, and configuration attributes into a near-unique signature.

Browser fingerprinting builds a quasi-unique identifier from attributes such as user agent, screen resolution, installed fonts, time zone, language, GPU and driver details, audio stack, and behavioural traits. Unlike cookies, it is stateless: the fingerprint is recomputed on every visit, which lets trackers re-identify users across sites and survive cookie clearing or private browsing. Research tools like the EFF's Cover Your Tracks and AmIUnique show that most browsers are uniquely identifiable from only a handful of attributes. Defences include the Tor Browser's uniform fingerprint, Safari's anti-fingerprinting mode, Firefox resistFingerprinting, and reducing entropy via standardised user agents and Privacy Budget proposals.

Defences for Browser Fingerprinting typically combine technical controls and operational practices, as detailed in the full definition above.

Common alternative names include: Device fingerprinting, Stateless tracking.