What Is My Screen Resolution?
A 1920 x 1080 screen has a 16:9 aspect ratio and about 2.1 megapixels. A 1440 x 900 screen at a device pixel ratio of 2 has 2880 x 1800 device pixels.
Reading screen values...
How to use
- Open the page. Your screen values appear right away; nothing to press.
- Resize the window, rotate your device or move the window to another monitor, and the values update.
- Press Copy to put a plain text summary on your clipboard, for example to paste into a support ticket.
How it works
Screen size is screen.width x screen.height, measured in CSS pixels. Browser viewport is window.innerWidth x window.innerHeight, the area a web page can use.
The physical resolution is an estimate: screen size multiplied by window.devicePixelRatio, rounded. On a display with a pixel ratio of 2, a 1440 x 900 CSS screen is shown as 2880 x 1800 device pixels.
Aspect ratio is matched to a common ratio such as 16:9 or 16:10 when it is within 0.5 percent; otherwise the exact reduced fraction is shown.
CSS pixels and device pixels
Web pages are laid out in CSS pixels so that text looks a similar size on different screens. A high density display packs more device pixels into each CSS pixel, and the device pixel ratio says how many fit across one CSS pixel.
Both operating system display scaling and browser zoom change this ratio, which is why the same monitor can report different values in different setups.
FAQ
Why does this show a lower resolution than my monitor's spec?
Browsers report sizes in CSS pixels. When your operating system scales the display, for example to 150 percent, one CSS pixel covers several device pixels. The estimated physical resolution multiplies by the pixel ratio to undo that.
Why do the numbers change when I zoom the page?
In many desktop browsers, page zoom changes the reported device pixel ratio and viewport size. Reset the zoom to 100 percent to read your normal values.
What is the difference between screen size and viewport?
Screen size is the whole display. The viewport is only the part inside the browser window where the page is drawn, without toolbars, tabs or scrollbars outside it.
Is the physical resolution always exact?
No. It is calculated from what the browser reports and can be off by a pixel from rounding, or differ when the browser or system uses a scaling factor it does not expose. Check your display settings for the exact native resolution.