What Your Browser Reveals About You

You don't have to log in, accept a cookie, or click anything. The moment a page loads, your browser hands it a surprisingly detailed profile — enough to recognize you again later without any cookies at all. This is what powers fingerprint-based tracking. Here's exactly what's exposed and how it adds up. See your own profile live with our browser checker.

Quick answer

Even in a fresh, cookie-free session, a website can read:

None of these identify you alone. Together, they form a fingerprint that's often unique.

How a fingerprint is built

Each detail your browser exposes carries some entropy — a measure of how much it narrows you down. One bit of entropy roughly halves the matching population:

• Your timezone splits the world into a few dozen buckets (~3–4 bits).
• Your screen + pixel ratio adds a few more bits.
• Your GPU model (via WebGL) is far rarer (~7 bits).
• Your canvas fingerprint — how your exact GPU, drivers, and OS render a hidden image — is one of the strongest signals (~8 bits).

Add them up and a typical desktop browser exposes 15–25 bits. Around 33 bits is enough to be unique among every person on Earth — so a fingerprint in the 20s already makes you highly identifiable, no cookies required. Our browser tool estimates your total bits and shows the breakdown.

The counterintuitive part: the more you customize your browser, the easier you are to fingerprint. A rare font, an unusual window size, or a niche extension all add entropy. A plain, default, up-to-date browser blends into the crowd.

The canvas fingerprint

The single most powerful signal is one you never see. A site draws text and shapes onto a hidden <canvas>, then reads the pixels back. Because rendering depends on your GPU, graphics drivers, OS, and font stack, the result varies subtly between devices — and is stable across sessions. Hash those pixels and you have an ID that survives cookie clearing and incognito mode. The same idea applies to WebGL (your GPU model) and audio rendering.

What the user agent gives away

The user agent string is the oldest signal: it names your browser, version, and OS in plain text. Modern browsers are freezing and trimming it to reduce tracking, but it still leaks plenty — and what the user agent reveals combines with everything else above. Client Hints are the newer, more controlled replacement.

What it can't directly see (but can infer)

• Your name or identity — not from the browser alone.
• Your exact location — but your IP gives city-level geo, and your timezone + language corroborate it even behind a VPN.
• Your real IP behind a VPN — usually hidden, unless WebRTC leaks it. Check that separately with our VPN leak test.

How to reveal less

1. Use a privacy-first browser — Tor Browser (strongest), or Brave/Firefox with privacy.resistFingerprinting.
2. Stay default and updated — an un-customized, current browser blends in; a heavily themed one stands out.
3. Trim extensions — each one can add detectable behavior and entropy.
4. Block canvas/WebGL where you can — some browsers prompt before exposing them.
5. Add a VPN for the IP layer — it won't change your fingerprint, but it hides the network identifier and approximate location. See browser fingerprinting & tracking for the full picture.

See your own exposure

Curious what your browser is broadcasting right now? Open the browser checker — it shows your fingerprint ID, an estimated identifiability score in bits, and a full category-by-category breakdown of every signal you expose, all computed in your browser. Pair it with the WebGL/GPU tool and the user agent tool to see the strongest signals up close.