What Is Browser Fingerprinting?
Browser fingerprinting is a tracking technique that collects technical details about your browser and device — without using cookies — to create a unique identifier for you. Every time you visit a website that uses fingerprinting, it can recognise you even if you clear your cookies, use private mode, or change your IP address.
Use our free Browser Fingerprint Checker to see exactly what data your browser is leaking right now.
What Data Does Browser Fingerprinting Collect?
A browser fingerprint is assembled from dozens of data points collected silently by JavaScript. These include:
- User Agent — your browser name, version, and operating system
- Screen resolution — width, height, colour depth and pixel ratio
- Canvas fingerprint — a unique hash of how your GPU renders text and graphics
- WebGL fingerprint — your graphics card manufacturer and renderer
- Timezone — your local timezone reveals your location
- Language — your browser's preferred language
- Installed fonts — the list of fonts available on your system
- CPU cores — the number of logical processors in your device
- Battery status — charge level and charging state (where available)
- Audio fingerprint — tiny differences in how your browser processes audio
Why Is Canvas Fingerprinting So Hard to Block?
When JavaScript draws text and shapes on an invisible HTML canvas element, your GPU, graphics drivers, and installed fonts all affect the final pixel output in subtly unique ways. The resulting image hash is almost always unique to your specific device and browser combination — and it never changes unless you change your hardware or graphics drivers.
This makes canvas fingerprinting particularly powerful because it works across incognito mode, VPNs, and even Tor in some configurations.
How to Protect Against Browser Fingerprinting
Complete protection is difficult but several approaches reduce your trackability significantly:
- Tor Browser — Standardises your fingerprint so all Tor users appear identical to websites. Most effective protection available.
- Brave Browser — Randomises your canvas and WebGL fingerprint on every website visit, making tracking impossible across sessions.
- Firefox with resistFingerprinting — Set
privacy.resistFingerprinting=truein about:config to enable Mozilla's built-in protection. - Privacy Badger — EFF's extension that blocks trackers it discovers through behaviour analysis.
- uBlock Origin — Blocks many fingerprinting scripts at the network level.
Browser Fingerprinting vs Cookies
Traditional cookies can be deleted — browser fingerprints cannot. This table shows the key differences:
- Cookies: Can be deleted ✓ — Fingerprints: Cannot be deleted ✗
- Cookies: Blocked by private mode ✓ — Fingerprints: Work in private mode ✗
- Cookies: Require consent under GDPR — Fingerprints: Consent requirements unclear
- Cookies: Stored on device — Fingerprints: Stored on server
Check Your Own Browser Fingerprint
Curious how unique your browser is? Our Browser Fingerprint Checker shows you your canvas hash, WebGL renderer, screen details, timezone, CPU cores, battery status, and a privacy score. It also checks for WebRTC leaks that could expose your real IP even through a VPN.
FAQs
Is browser fingerprinting legal?
It exists in a legal grey area. In the EU, collecting fingerprint data without consent may violate GDPR. In the US, regulations are less clear. Many advertising networks use fingerprinting as a backup to cookies.
Does a VPN stop fingerprinting?
No. A VPN hides your IP address but does not change any of the browser properties used for fingerprinting. You need browser-level protection like Brave or Tor Browser to prevent fingerprint tracking.
Can I use incognito mode to avoid fingerprinting?
Unfortunately not. Incognito mode prevents cookies from being saved but your browser still sends the same canvas hash, screen resolution, User Agent, and all other fingerprint data as normal browsing mode.