Free Tool
Browser Fingerprint Demo
Every website you visit can read a set of facts about your browser — its type and version, your screen size, your timezone, your language. On their own these facts are harmless. Together they can single you out. This demo shows you exactly what your browser reveals, computed entirely on your device, with no identifier created, stored or sent anywhere.
Education, not identification. This page displays the signals your browser already reveals to every site you visit. It never combines them into a fingerprint identifier, never stores anything, and never sends anything anywhere.
What this tool does
Browser fingerprinting is a way of identifying a visitor without a cookie. Instead of storing something on your device, a website reads the facts your browser volunteers — the browser name and version, the operating system, the screen size and colour depth, the timezone, the language, the list of installed fonts, and more — and combines them into a profile. Most visitors share many of those facts, but the combination is often unique enough to recognise the same browser again on a later visit, even after cookies are cleared.
This demo shows you the signals themselves, on your own browser, in plain sight. It reads the same values any website can read — through the browser's standard navigator and screen objects — and displays them, with a plain-English note on what each one reveals and how much it varies between people. There is no scoring, no identifier and no database: the demo exists so you can see the raw material, not so it can label you.
The demo is deliberately limited. It reads only the most basic, widely known signals, and it stops short of the techniques that make fingerprinting powerful — canvas rendering, font enumeration, hardware details — because the point is to teach the concept, not to build the tool. The privacy guide linked below explains why the uniqueness figures quoted online disagree so wildly, and what, if anything, you can actually do about fingerprinting.
Try it
These are the signals your browser reveals to every website you visit, read live from this device. Nothing here is stored, sent or combined into an identifier.
Reading your browser's signals… If nothing appears, your browser is blocking access to this information.
What this demo does NOT do. It does not combine these signals into a fingerprint identifier. It does not store them, send them anywhere, or remember your visit. A real fingerprinting script would do all of those things — this page exists to show you the raw material, not to use it.
How it works
Your browser exposes information through built-in objects that any website can read. The navigator object gives the user agent string (browser name and version, operating system), the language, the number of processor cores, and, in some browsers, the amount of device memory. The screen object gives the screen width, height and colour depth, and the window gives the size of the browser viewport. The Intl API gives the timezone. None of this requires permission, because it was designed for legitimate purposes: a website needs to know your screen size to lay out its pages, and your language to show you the right text.
Fingerprinting works by combining many such signals. Any one of them is shared by millions of people — a screen width of 1920 pixels, a timezone of Europe/London — but the combination narrows the group down. Add the exact browser version, the operating system build, the installed fonts and the way the browser draws a graphic, and the combination can become unique to a small group or even to one person. That is the sense in which a fingerprint works: not one fact, but the pattern of many.
The published uniqueness figures disagree wildly — studies have found anything from a third to almost all browsers uniquely identifiable — because the studies measured different signals, in different years, on different populations. The guide linked below explains why those numbers disagree, and why a figure quoted without its method and its year is meaningless. What is not in dispute is the mechanism: the signals are real, they are readable by any site, and they are the reason tracking works even without cookies.
Limitations
This demo shows only the most basic fingerprinting signals. It does not measure how unique your browser is, because uniqueness depends on the whole population of browsers, which a single page cannot know. It does not use canvas fingerprinting, font enumeration or other advanced techniques, and it deliberately does not combine the signals into an identifier — which is the step that turns information into tracking.
- The values shown depend on your browser and its settings. Privacy-focused browsers may hide or randomise some of them, and the demo shows whatever your browser currently reveals.
- The demo cannot tell you whether you are being fingerprinted elsewhere. It shows the raw material, not a diagnosis.
- Nothing is stored or sent. Close the page and the reading is gone.
Examples
Example 1 — the user agent. Your browser tells every site its name, version and operating system in a single string, so the site can serve the right layout. That string is shared by millions of people with the same browser version, so on its own it identifies almost nothing — but it is one of the pieces a fingerprint is built from, and an unusual browser or an old version stands out far more than a common one.
Example 2 — screen plus timezone. A screen of 1920 by 1080 is common. A timezone of Asia/Karachi is common. Together they narrow the group, and with a language setting and a browser version added, the group narrows further. No single signal is the fingerprint; the combination is. That is why the demo lists the signals separately, with a note on each, rather than giving you a single score.
Example 3 — what you can actually do. You cannot stop your browser revealing a screen size or a language — websites need those to work. What you can do is use a browser that reduces fingerprinting, such as a privacy-focused browser that presents a common, standardised set of values, keep your browser updated so your version is common rather than rare, and use a reputable tracker blocker. The privacy guide explains the options honestly, including the fact that there is no perfect defence.
Frequently asked questions
What is browser fingerprinting?
A way of recognising a visitor without cookies: a website reads the facts your browser volunteers — browser version, screen size, timezone, language, fonts — and combines them into a profile that is often unique enough to recognise the same browser again.
Does this demo fingerprint me?
No. It displays the signals your browser reveals, but it never combines them into an identifier, never stores them, and never sends them anywhere. A real fingerprinting script would do all of those things — this page exists to show you the raw material.
Can I stop websites fingerprinting me?
Not completely. You can reduce it with a privacy-focused browser, an up-to-date browser version, and a tracker blocker — but a browser has to reveal its screen size and language to work at all. There is no perfect defence, and any site that promises one is overselling.
Why do fingerprinting statistics disagree so much?
Because studies measure different signals, in different years, on different groups of people. A figure is meaningless without its method and its year — some studies found a third of browsers unique, others almost all. The guide on this site explains the disagreement.
Is fingerprinting illegal?
It depends on the country and on whether consent is required for tracking. In the EU, fingerprinting for tracking generally needs consent under privacy law. The details differ by jurisdiction, and this page is not legal advice.