Network · Browser
What is my screen resolution?
Your screen size in pixels is shown the moment the page loads, with the pixel ratio, aspect ratio and orientation your browser reports.
Your screen resolution
Details
How to read your result
The big number is screen.width by screen.height, the size of the screen in CSS pixels, as defined in the CSSOM View Module. A CSS pixel is not always one hardware pixel: on a high-density display the browser draws several device pixels for each CSS pixel, and the device pixel ratio is that count.
The "estimated physical pixels" row multiplies the two. It is an estimate, because the spec bases the ratio on the page zoom, so zooming the page in or out changes it. Operating-system display scaling (for example 125% on Windows) also shrinks the reported size, so a 1920 × 1080 monitor can report a smaller number here. Reset browser zoom to 100% for the closest match to your native resolution. The spec also lets browsers hide screen details to protect privacy, in which case they may report the size of the browser viewport instead of the screen.
Screen resolution is not the same as the space your page gets. The browser window and its viewport are usually smaller; use the viewport size checker for that.
Sources (retrieved October 2026): CSSOM View Module (W3C); Media Queries Level 5 (W3C).
Frequently asked questions
Why is the number smaller than my monitor's native resolution?
Browsers report the screen in CSS pixels. If your operating system scales the display (125%, 150%, 200%), the reported size is the native size divided by the scale. The estimated physical pixels row multiplies it back using the device pixel ratio.
What is the device pixel ratio?
It is the number of device pixels per CSS pixel. A ratio of 2 means each CSS pixel is drawn with a 2 by 2 block of hardware pixels, which is how high-density screens stay sharp. Page zoom changes it.
Is screen resolution the same as window size?
No. Screen resolution is the size of the display. The window and viewport are the part the browser gives to the page. The viewport size checker shows that number live.
What does the aspect ratio row mean?
It is the screen width divided by its height, reduced to the simplest ratio, and matched to a common name (such as 16:9 or 16:10) when it is within 1%.
Is anything sent to a server?
No. The numbers are read from your browser on this page and are not stored or transmitted.
Private by design
This tool reads values from your own browser and shows them on this page. The tool does not store them, send them to TNAADO or pass them to any other service. What your browser reports can be reduced or changed by privacy settings and extensions, so treat it as what the browser says, not as proof.