Device info
Everything the site you just opened knows about you without asking: browser, system, screen, network, even which theme you prefer. Nothing is sent to a server — it is read in your browser and stays there.
What this page is actually showing you
You were not asked for permission for a single value above — any site can read all of them silently. On their own they are harmless, but combined they form a fingerprint that is rarely shared by two people: screen size, time zone, language list, core count and your theme preference. That is why clearing cookies or opening a private window does not stop tracking on its own. None of this data leaves the page: it is read in your browser and stays there.
Frequently asked questions
What is a fingerprint, and is this page part of it?
A fingerprint is the set of signals that lets a site recognise your browser with no cookie at all. Screen size says nothing on its own, and neither does a time zone — but a few dozen such values together can single you out among millions. This page shows exactly those values and sends none of them anywhere: the point is to show you how the technique works, not to use it.
Why is the browser version incomplete?
Chrome froze the version in its User-Agent string in 2022 — the minor numbers read 0.0.0 for everyone, because that precise number was one of the strongest fingerprinting signals. The real version now comes from User-Agent Client Hints, which this page asks for first. The “Source” row tells you which one answered: hints means the exact value, ua means it was parsed out of the frozen string.
Why do some rows say “not reported”?
Because parts of this are Chromium-only. Device memory, connection quality and Client Hints do not exist in Firefox or Safari, which decline to implement them precisely to reduce fingerprinting. Those rows are kept rather than hidden: what your browser refuses to say is an answer too.
Why are the screen and window sizes different?
The screen is your whole monitor. The window is the area the page is actually drawn in, with the browser chrome, any sidebars and the scrollbar taken off. CSS media queries measure the second one, so that is the number to design against. Resize the window and watch the value above change immediately.
How much of this can I trust?
The device type and operating system are inferences drawn from the User-Agent string, which can be changed and often is. An iPad, for instance, presents itself as a Mac — which is why the touch-point count is taken into account here. The screen, window, languages and preferences are not inferences: they are read directly from the browser.