Browser fingerprinting is the collection and analysis of browser attributes — installed fonts, screen resolution, WebGL renderer, audio context, timezone, plugin list, canvas rendering output — to create a unique identifier for a client without using cookies.
Anti-bot systems use fingerprinting to track clients across IP changes and detect bots that rotate proxies but maintain a consistent technical fingerprint. Defeating fingerprinting requires a full browser environment with realistic, randomized attribute values. Playwright's stealth plugins and commercial tools like Bright Data's Scraping Browser provide hardened browser instances specifically designed to pass fingerprint-based challenges.