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Screen Resolution Detector

Find your screen resolution, viewport and pixel ratio.

What is my screen resolution?

Screen resolution is the number of pixels your display shows, written as width × height (for example 1920 × 1080). Browsers report it in CSS pixels; multiplying by the device pixel ratio gives the physical pixels of high-density screens.

The numbers explained

  • Resolution — the screen size in CSS pixels as the browser sees it.
  • Viewport — the visible area inside the browser window. This is what responsive designs react to.
  • Pixel ratio — physical pixels per CSS pixel. Retina and most phones are 2–3; standard monitors are 1. Windows display scaling (125 %, 150 %) also changes it.
  • Physical pixels — resolution × pixel ratio, close to the panel's native resolution.
  • Colour depth — usually 24-bit (16.7 million colours).

Why designers care

Responsive layouts use breakpoints based on viewport width. Images should be supplied at 2× for high-density screens (using srcset) so they look sharp without wasting bandwidth on standard screens.

Popular resolutions

Desktop: 1920 × 1080, 1366 × 768, 1536 × 864, 2560 × 1440. Mobile viewports: 360–430 CSS pixels wide.

Test how a site looks at other sizes with the Screen Resolution Simulator. See full browser details with What Is My Browser.

Frequently asked questions

How do I check my screen resolution?

Open this page. Your resolution, viewport size and pixel ratio are detected automatically.

Why is the resolution lower than my monitor's specs?

Browsers report CSS pixels. With display scaling or a high-density screen, multiply by the pixel ratio to get physical pixels.

What is the difference between resolution and viewport?

Resolution is the whole screen; the viewport is the visible area inside the browser window.