Browser Fingerprinting: How 12 Lines of JavaScript Identify You Without Cookies

📰 Dev.to · Max

Learn how 12 lines of JavaScript can identify you without cookies using browser fingerprinting techniques like Canvas API, AudioContext, and WebGL

intermediate Published 4 Apr 2026

Action Steps

Run a Canvas API fingerprinting test using JavaScript to measure entropy
Configure AudioContext to collect audio fingerprints
Test WebGL rendering to collect graphics fingerprints
Apply browser fingerprinting defenses like script blocking or anti-fingerprinting extensions
Compare entropy measurements to determine the effectiveness of fingerprinting techniques
Build a proof-of-concept to demonstrate browser fingerprinting vulnerabilities

Who Needs to Know This

Developers and cybersecurity professionals can benefit from understanding browser fingerprinting to protect user privacy and prevent tracking

Key Insight

💡 Browser fingerprinting can identify users without cookies using techniques like Canvas API, AudioContext, and WebGL

Key Takeaways

Learn how 12 lines of JavaScript can identify you without cookies using browser fingerprinting techniques like Canvas API, AudioContext, and WebGL

Full Article

How Canvas API, AudioContext, and WebGL fingerprint your browser without cookies. Code examples, entropy measurements, and what actually defends against it.

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