What is the difference between CSS pixels and real pixels?

CSS pixels are the units web pages are built in. Real (device) pixels are the physical dots on the screen. The device pixel ratio is the number of real pixels per CSS pixel along each side, so a ratio of 2 means 4 real pixels for every CSS pixel. The page shows both figures for your screen, with the multiplication spelled out.

Why does my screen resolution change when I zoom the browser?

Browser zoom changes the CSS size of the screen and the window and the device pixel ratio at the same moment. The real pixel figure at the top stays about the same, but the CSS figures, the ratio and the viewport size change. The numbers on the page update live, so you can watch it happen.

What is the viewport size and why is it smaller than my screen?

The viewport is the page area inside your browser window, in CSS pixels. It is smaller than the screen because of the browser's toolbars, tabs, scrollbars, and any window that is not maximised. It updates live when you resize the window. The page also shows the whole window size and the screen's available area.

How does the page know my refresh rate, HDR and touch support?

The refresh rate is measured by counting animation frames for about 3 seconds. HDR and colour gamut are read from the browser's media queries, and touch support from the number of touch points the browser reports. If a browser does not report something, the page says "Not reported by this browser". Press "Copy all details" to copy everything as plain text.

Yes. Every tool is free to use, with no account and no credit card. The work runs on your device rather than on our servers, which is what keeps it free to run.

Does it work on mobile?

Yes. It runs in current mobile browsers on iOS and Android, with nothing to install.

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Free What Is My Screen Resolution

Q: What is my screen resolution?

The large figure at the top of the page is your screen resolution in real pixels, calculated as the browser's screen width and height multiplied by the device pixel ratio. The same size in CSS pixels, the pixel ratio and the aspect ratio are listed below it. If your pixel ratio is not a whole number, the real figure is rounded.

See your screen resolution in CSS and real pixels, window size, pixel ratio, colour depth, HDR, touch support and refresh rate, and copy it all.

Runs in your browserNo sign-up, no pop-upsNo login requiredFree foreverCSS and real pixelsLive window sizeCopy all details

Reading your screen...

How It Works

The page asks your browser for the size and capabilities of your screen and window, and shows them in plain terms.

1
Read your resolution
The top figure is your screen size in real pixels, worked out from the browser's CSS size and the device pixel ratio.
2
Resize and watch
Resize the window, rotate the device or zoom the page. The window and ratio figures update live.
3
Check the details
See colour depth, HDR, colour gamut, touch support and the measured refresh rate. Press "Measure refresh rate again" to repeat that measurement.
4
Copy everything
Press "Copy all details" to put every figure on your clipboard as text, for example to send to support.

These details stay in your browser tab. Nothing is stored or uploaded.

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Free What Is My Screen Resolution

How It Works

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Frequently Asked Questions