Modern browsers expose a surprisingly large amount of information to websites through standard web APIs. Much of this was designed for legitimate purposes (responsive design, accessibility, web apps) but is also used for tracking and fingerprinting.
Data Your Browser Can Expose
| Data Point | How Websites Access It | Privacy Risk |
|---|---|---|
| IP address | HTTP headers; WebRTC | High |
| Screen resolution | window.screen API | Medium (fingerprinting) |
| Browser and OS version | User-Agent header | Medium |
| Installed fonts | Canvas API text rendering | High (very unique) |
| GPU model | WebGL RENDERER string | High (very unique) |
| Time zone | Intl.DateTimeFormat API | Medium |
| Language settings | navigator.language | Low |
| CPU core count | navigator.hardwareConcurrency | Medium |
| Battery level | Battery Status API (where supported) | Medium |
| Do Not Track setting | navigator.doNotTrack | Low (mostly ignored) |
How to Check What Your Browser Leaks
Use our Browser Fingerprint tool to see exactly what your browser exposes and how unique your combination is.
How to Reduce Leakage
- Brave Browser: Randomizes fingerprinting data (Canvas, WebGL, fonts) per session
- Firefox: Enable
privacy.resistFingerprintingin about:config - uBlock Origin: Blocks many tracking and fingerprinting scripts
- VPN: Hides your real IP from websites
- WebRTC disabled: Prevents IP leaks via browser video/voice features
People Also Ask
- What browser is 100% safe?
- No browser is 100% safe, but Brave and Firefox with privacy settings enabled minimize fingerprinting, block trackers, and protect against common leaks. Tor browser offers the strongest anonymity at the cost of speed.
Related: Fingerprinting | Cookies | Fingerprint Check