How Do Websites Track You?
Modern websites use a combination of techniques to track users across the web. Even with cookies disabled, sophisticated fingerprinting can identify your browser with surprising accuracy.
Browser Fingerprinting
Your browser reveals a surprisingly unique combination of information: your browser version, operating system, installed fonts, screen resolution, timezone, language settings, hardware capabilities and even the way your graphics card renders certain images (canvas fingerprinting). When combined, this "fingerprint" can identify you across websites without any cookies.
Why Canvas Fingerprinting Actually Works
A canvas fingerprint script asks your browser to render text or shapes onto an invisible HTML5 canvas element, then reads back the resulting pixel data as a hash. Tiny differences in your GPU, graphics driver, operating system font rendering, and even anti-aliasing settings produce subtly different pixel output for the exact same drawing instructions — two devices that look identical on paper can still render measurably different pixels, which is what makes this hash such a reliable, hard-to-fake identifier even across browser restarts.
Why Privacy Scores Differ Between Tools
Getting a different score on two different privacy-testing sites for the same browser session isn't a bug in either tool — each one weighs its checks differently and tests for a different set of signals (some emphasize WebRTC leaks more heavily, others weight cookie handling or canvas fingerprint uniqueness more). Treating any single score as an absolute number is less useful than looking at which specific checks failed and fixing those directly, since the underlying technical issues are what actually matter, not the summary number a particular tool assigns them.
WebRTC IP Leaks
WebRTC is a browser technology for real-time communication (video calls, etc.). Unfortunately it can leak your real IP address even when you are connected to a VPN. If a website uses JavaScript to create a WebRTC peer connection, it may reveal your actual IP through the ICE negotiation process.
Cookies and Local Storage
Traditional tracking cookies allow websites and advertisers to track your browsing history across sites. Local storage and IndexedDB are newer alternatives that persist even when cookies are cleared. A robust privacy setup blocks third-party cookies and clears storage regularly.
How to Improve Your Privacy Score
- Use Brave or Firefox with uBlock Origin
- Enable DNS over HTTPS to prevent DNS leaks
- Use a reputable VPN and verify it does not leak via WebRTC
- Disable WebRTC in your browser settings (or use an extension)
- Enable privacy.resistFingerprinting in Firefox
Test Your Browser Privacy
Our Browser Privacy Score runs 12 real-time checks on your browser and gives you a score from 0-100 with specific advice on what to improve.
