What is my screen resolution?
The page reads your display in your browser and shows the screen size in CSS pixels, the real pixel count, the pixel ratio and the size of the window you are looking at. The numbers update when you resize the window or rotate your phone.
Runs in your browser: nothing you enter is sent anywhere.
What you see
- Screen size in CSS pixels, and physical pixels (screen size × pixel ratio).
- Aspect ratio, reduced to the simplest form, such as 16:9. If the ratio does not reduce to small numbers it is shown as a decimal like 1.78:1.
- Device pixel ratio, browser window size, the available area without the taskbar, color depth and orientation.
All of it is read when the page loads in your browser and again when you resize the window or rotate the device. The page’s own HTML shows dashes, because it cannot know your device until it runs in your browser.
Worked example
A laptop reports a screen of 1536 × 864 with a pixel ratio of 1.25. Physical pixels are 1536 × 1.25 = 1920 and 864 × 1.25 = 1080, so the real display is 1920 × 1080. The aspect ratio is 1536 : 864, which reduces by 96 to 16:9.
Tips
- Reading the real resolution. Use the Physical pixels line, and set browser zoom to 100 % for a clean reading.
- Designing for the web. Layouts respond to the viewport in CSS pixels, not to physical pixels.
- Dead or stuck pixels? Use the dead pixel test to check the screen.
Frequently asked questions
Why is my screen size smaller than the resolution in my display settings?
Browsers report sizes in CSS pixels, which are scaled by the device pixel ratio. A display with 3840 × 2160 real pixels set to 200 % scaling is reported as 1920 × 1080. The Physical pixels line multiplies it back.
What is the device pixel ratio?
It is how many real pixels the screen uses for one CSS pixel. It is 1 on a standard display and 2 or more on high-density screens. Browser zoom also changes it, so it may change when you zoom.
What is the difference between screen and viewport?
Screen is the whole display. The viewport is the part of the browser window that shows the page, without toolbars and scrollbars. Resize the window and only the viewport changes.
Are these numbers exact?
They are what the browser reports. Physical pixels are an estimate, the CSS size times the pixel ratio, and fractional zoom levels can make it a pixel or two off. Some browsers also round or limit values for privacy.
Is anything sent from my device?
No. The values are read on the page and shown to you. Nothing is uploaded.