Browser Fingerprinting: How Sites Track You Without Cookies
Cookies Are Not the Only Way You Are Tracked
You have probably heard of cookies. You might even clear them regularly. But there is a more insidious tracking method that does not store anything on your device: browser fingerprinting.
What Is a Browser Fingerprint?
A browser fingerprint is a collection of attributes your browser reveals to every website you visit. These include your screen resolution, installed fonts, browser plugins, timezone, language, operating system, GPU renderer, and dozens more data points. Combined, they create a unique identifier. Check your browser fingerprint now.
Why It Works
The Electronic Frontier Foundation found that 83.6% of browsers have a unique fingerprint. Even without cookies or login sessions, a website can identify you across visits with high accuracy. Your browser reveals enough information to distinguish you from millions of other users.
What Gets Collected
Common fingerprinting vectors include:
Canvas fingerprinting renders invisible text and measures pixel-level differences caused by your GPU and OS. WebGL fingerprinting queries your graphics hardware. AudioContext fingerprinting measures how your system processes audio signals. Even your battery level has been used for tracking on some platforms.
Who Uses It
Advertising networks use fingerprinting to track users who block cookies. Fraud detection services use it to identify suspicious logins. Some governments and law enforcement agencies use it for surveillance. Virtually any website can deploy fingerprinting scripts. Combined with WebRTC leaks and DNS leaks, fingerprinting makes it possible to track users even behind a VPN.
How to Reduce Your Fingerprint
Use the Tor Browser, which is designed to make all users look identical. Use browser extensions like CanvasBlocker to randomize fingerprint data. Avoid installing unusual fonts or plugins. Use a common screen resolution. Disable JavaScript on sensitive sites (though this breaks most of the web).
The Hard Truth
Browser fingerprinting is nearly impossible to fully defeat without significant usability trade-offs. The best approach is to minimize your unique attributes and use privacy-focused browsers. Start by understanding what your browser reveals with our fingerprint analysis tool.