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.
Processed entirely in your browser — nothing you enter here is ever uploaded.
Result
About this tool
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.
Example. On load the page fills screen width and height, the inner viewport, devicePixelRatio, color depth, and orientation, then updates those fields when the window is resized.
Limit. The readout is the current screen and viewport only, so a second monitor that does not contain the window is not listed.