What Your Browser Reveals

What it's for

Any web page can read a lot about your browser and device without asking: your languages and time zone, your screen, your graphics chip, which fonts you’ve installed. Together these are often unique enough to recognise you across sites and visits without cookies, which is called fingerprinting. This page reads the same things and shows them to you, with why each one matters.

For example, when you’re trying a privacy setting, an extension or a VPN, open this before and after to see what actually changed, and whether the fingerprint changed with it.

How to use it

It reads everything when the page opens and shows it in sections: Browser, Language and time, Screen and window, Hardware, Settings you chose, Privacy signals (including the answers to permission questions, which a page can see without asking you) and Fingerprinting. A row a browser doesn’t give is left out, so Safari and Firefox show fewer than Chrome.

Fingerprint is a short hash of the values that rarely change, made the way trackers combine them. If it stays the same in a private window, a site can recognise you there too. Read again reads everything again (after resizing the window, say), and Copy all copies it as text.

Example

Open the page in a normal window and note the Fingerprint. Open it again in a private window: in most browsers the cookies are gone but the fingerprint is the same. Change the window’s size and choose Read again: the window size changes, but the fingerprint doesn’t, as it uses the screen size instead.

Good to know

Nothing here is sent anywhere; this site has no server code to receive it. Every site also sees your IP address and the headers your browser sends, which a page in the browser can’t read, so they aren’t shown. The fonts are tested from a list of common ones; Safari and Firefox’s fingerprinting protection hide some fonts and values, or add noise to the canvas drawing, so the hash may change between visits there, which is the point.