What Is My Screen Size? Check It Instantly
See your screen resolution, browser viewport size, device pixel ratio, color depth and orientation — updated live as you resize.
Result
The answer is already on this page: the tool above reads your screen size directly from the browser the moment the page loads — resolution in pixels, the browser viewport, pixel ratio, color depth and orientation.
Note that two different numbers both get called "screen size". The display resolution (for example 1920×1080) is what your monitor reports; the viewport is the part your browser really uses for pages, and it is always a bit smaller. Websites see the viewport — which is why a designer and a tester can name different numbers for the same laptop.
If you need the full picture for a bug report, copy the summary line under the values — it packs resolution, viewport and pixel ratio into one string. And since everything is read locally by your own browser, no measurement ever leaves your device.