Browser fingerprint test

What a browser fingerprint is

Cookies are a label a website sticks on your browser. A fingerprint is the opposite: nothing is stored on your device. Instead, a script reads dozens of ordinary facts — screen resolution, the graphics card your browser reports through WebGL, how your system draws text and shapes on a hidden canvas, how it processes a short audio signal, which fonts are installed, your time zone, your language list — and combines them into one identifier. Each fact on its own is shared by millions of people. Together they often narrow you down to a handful of browsers, or to one.

Because nothing is saved on your device, clearing cookies, using private mode or switching on a VPN does not reset it. That is what makes fingerprinting attractive to ad-tech and, legitimately, to fraud-prevention systems that want to notice when a stolen password is used from an unfamiliar device.

How to use it

1. Open the page. Your fingerprint ID is computed in your browser within a moment, with a note of how many signals returned a value.
2. Press Copy ID and paste it somewhere you can find again, so you have a baseline.
3. Read the grouped cards: Display, Hardware, Rendering, Locale, Browser and, in Chromium browsers, Client hints. The chip on each row says whether you can change that value, only partly, or not at all. A value of Unknown means the browser gave no answer.
4. Open Fonts we detected to see which of the tested fonts your system has installed.
5. Change a single thing, such as a private window, another profile, a privacy setting or an extension, then load the page again and compare the new ID with your baseline.
6. If the ID changed, go through the cards to find the row that moved.

Change one thing per round; with two changes at once you cannot tell which one mattered. Resizing the window does not touch Screen size, which reports the display, but moving the browser to another monitor can.

Use cases

• Testing whether clearing cookies is enough. Copy the ID, clear cookies and site data, then reload. An unchanged ID shows why deleting cookies alone does not stop this kind of recognition.
• Checking separate browser profiles. If you keep work and personal browsing in different profiles, compare their IDs. Matching IDs mean a site reading these signals could link the two.
• Measuring a privacy setting. Turn on your browser's anti-fingerprinting option, reload, and see which rows changed and which stayed put.
• Reviewing an automated or headless browser. QA engineers can see whether the automation flag is set and whether the Graphics (WebGL) row names a software renderer such as SwiftShader or llvmpipe instead of a real GPU, two details bot-detection scripts commonly check.
• Seeing what new software adds. After installing an office suite or a language pack, the fonts count can rise, which makes the browser more distinctive.
• Showing colleagues what a VPN leaves alone. Load the page with and without the VPN: the ID stays the same, because none of these signals come from your network.

The signals, explained

• Display: screen size, available area (screen minus taskbars), pixel ratio and colour depth. Laptops with scaled displays produce unusual combinations.
• Hardware: the number of CPU threads, a rounded memory figure, touch support and the graphics renderer string, which can name your exact GPU model.
• Rendering: canvas and audio hashes. The same drawing or sound produces slightly different bytes depending on your GPU, drivers, operating system and fonts, so the hash is stable on one machine and different across machines.
• Fonts: we test 40 common fonts by measuring text width. Office suites, design tools and language packs install fonts that set you apart.
• Locale: time zone, locale and language list. These are settings, and they are also what sites compare with your IP address to spot a VPN.
• Browser: platform, cookie and storage support, the built-in PDF viewer, Do Not Track, Global Privacy Control and the automation flag that Selenium and Playwright set.
• Client hints: in Chromium browsers, the platform version, CPU architecture and full browser version list.

Why we show an ID but not a "uniqueness score"

Sites like AmIUnique and the EFF's Cover Your Tracks tell you how rare your fingerprint is by comparing it with fingerprints collected from earlier visitors. That requires a database of visitors' fingerprints, and iseeu.cc keeps no data about visitors at all. So instead of a score, we give you a way to test the thing that actually matters to you: open this page in another browser profile, a private window or after changing a setting, and see whether the ID changes. If it does not, that change did not protect you.

How to reduce your fingerprint

• Blend in rather than stand out. Unusual settings, rare fonts and many extensions make you more distinctive, not less.
• Use a browser with built-in protection. Tor Browser makes all its users look the same; Brave randomises canvas, audio and other values per site; Firefox's strict tracking protection blocks known fingerprinting scripts, and its privacy.resistFingerprinting option standardises many values.
• Keep your browser updated. Current versions reduce the detail they expose, for example Chrome's frozen User-Agent string.
• Separate identities by browser profile. A different profile still shares hardware signals, but extensions, storage and settings differ.
• Don't rely on a VPN for this. It hides your IP address, which is a different problem.

No browser makes you invisible: a protected browser is still recognisably that browser. The aim is to look like a large crowd.

Frequently asked questions

The fingerprint ID on this page is computed by our own script and will differ from IDs produced by commercial fingerprinting products, which use other signals. It is a demonstration, not a measure of how trackable you are on any particular site.