Do websites really see all of this?

Yes — every field here is readable by any site's JavaScript without permissions. Individually harmless, collectively they form the fingerprint that makes ad tracking possible.

Why does my screen size look smaller than my display?

The values are CSS pixels of the window, not hardware pixels; pixel ratio multiplies them for the physical panel. A 4K screen with DPR 2 reports half the width in CSS pixels.

Can I change what I reveal?

Partially — privacy extensions and some browser settings spoof or freeze fields like the user agent. Reload this page after changing them to see what the spoof looks like to sites.

Device information — Guide

Get information about your current device (screen size, pixel-ratio, user agent, ...)

What it is and when to use it

See what your browser tells websites about this device: screen and window size, pixel ratio, colour depth, orientation, user agent, platform and languages. The quick answer to "what fingerprint am I presenting" and a handy reference when debugging layout or feature-detection issues.

Shows the current device screen size, pixel ratio, User-Agent and more — useful evidence when debugging compatibility issues.

How to use it

Open the page to see all the information
Copy the fields you need

Things that trip people up

The figures are what the browser reports through its own APIs — privacy modes and extensions can round, freeze or spoof them, so treat them as reported values, not ground truth about the hardware
Anything the browser does not expose, or a hardened browser hides, is shown as "unknown"; the page lists only standard Web API fields

Questions people ask

Do websites really see all of this?: Yes — every field here is readable by any site's JavaScript without permissions. Individually harmless, collectively they form the fingerprint that makes ad tracking possible.
Why does my screen size look smaller than my display?: The values are CSS pixels of the window, not hardware pixels; pixel ratio multiplies them for the physical panel. A 4K screen with DPR 2 reports half the width in CSS pixels.
Can I change what I reveal?: Partially — privacy extensions and some browser settings spoof or freeze fields like the user agent. Reload this page after changing them to see what the spoof looks like to sites.

Next steps

Open the Device information tool

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