Browser Fingerprinting
A tracking technique that identifies users by collecting unique combinations of browser and device characteristics without using cookies.
Browser fingerprinting (or device fingerprinting) is a tracking method that identifies users by collecting a combination of attributes from their browser and device — including screen resolution, installed fonts, browser plugins, timezone, language settings, WebGL rendering data, and more. When combined, these data points create a nearly unique fingerprint that can track users even if they clear cookies, use private browsing, or switch between accounts.
Fingerprinting is considered more invasive than cookies because users cannot easily detect, control, or prevent it. The GDPR and ePrivacy Directive treat fingerprinting the same as cookies — it requires consent because it accesses information from the user’s device. The French data protection authority (CNIL) has specifically addressed fingerprinting in guidance, and several enforcement actions have targeted its use without proper consent. Some browsers now implement anti-fingerprinting measures, randomizing certain attributes to make tracking more difficult.