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SPCXTools

Screen Resolution

See your screen resolution, browser viewport size, pixel ratio and other display details instantly.

Runs locally — files never leave your device

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How to use Screen Resolution

  1. 1Open the page — your screen resolution is shown immediately at the top.
  2. 2Check the details below — CSS resolution, device pixel ratio, viewport size, aspect ratio, colour depth and more.
  3. 3Resize the browser window or rotate your device; the values update live.
  4. 4Click Copy to share all details, for example in a bug report.

What is my screen resolution?

Your screen resolution is the number of pixels your display shows horizontally and vertically, such as 1920 × 1080. This tool detects it instantly, together with the details web designers, developers and support teams usually need: the CSS resolution, device pixel ratio, browser viewport size, available screen space, aspect ratio, colour depth, colour gamut and HDR support. Everything is read locally from your browser.

Understanding the numbers

Physical resolution is the real number of pixels on the panel (for most setups). It is what manufacturers advertise, e.g. 2560 × 1440.

CSS pixels are the logical units websites use. When your system scales the display — for example 200% on a Retina screen — one CSS pixel covers several physical pixels, so text stays a readable size while looking sharper.

Device pixel ratio connects the two: physical pixels = CSS pixels × DPR.

Viewport is the visible page area inside the browser. It changes whenever you resize the window, open developer tools or show the bookmarks bar.

Common screen resolutions

Name Resolution Aspect ratio
HD (720p) 1280 × 720 16:9
Full HD (1080p) 1920 × 1080 16:9
WUXGA 1920 × 1200 16:10
QHD (1440p) 2560 × 1440 16:9
UWQHD (ultrawide) 3440 × 1440 21:9
4K UHD 3840 × 2160 16:9
5K 5120 × 2880 16:9

Who needs this information

Web designers and developers test responsive layouts against real viewport sizes and pixel ratios, and need them to reproduce visitors' bug reports.

Support and IT teams ask for screen details when troubleshooting display or layout issues — use the Copy button to send everything at once.

Gamers and creators confirm that a new monitor is running at its native resolution rather than a scaled or lower mode.

Anyone buying wallpapers, screenshots or presentations can match images to their exact screen size for the sharpest result.

Check how fast your display updates with the Refresh Rate Test, or look for faulty pixels with the Dead Pixel Test.

Frequently asked questions

Why is the resolution different from my monitor's specification?
Operating systems often scale the interface. A 3840 × 2160 (4K) monitor at 150% scaling reports a "CSS" resolution of 2560 × 1440 to websites, with a device pixel ratio of 1.5. The Screen resolution at the top multiplies these back to physical pixels. Browser zoom also changes the pixel ratio, so reset zoom to 100% (Ctrl/Cmd + 0) for accurate results.
What is the device pixel ratio (DPR)?
DPR is the number of physical pixels per CSS pixel. A standard monitor has a DPR of 1; Retina Macs and most phones have 2 or 3. High-DPR screens show sharper text and images because each CSS pixel is drawn with several physical pixels.
What is the viewport, and why does it matter?
The viewport is the area inside the browser window where web pages are displayed, excluding toolbars and tabs. Web designers use it — not the full screen size — for responsive layouts, so it is the most useful number when reporting how a website looks on your device.
What does "available" screen size mean?
It is the screen area minus permanent operating-system elements such as the Windows taskbar or macOS menu bar and Dock — the largest size a window can be without overlapping them.
Is the reported HDR and colour gamut accurate?
It reflects what the browser reports through CSS media queries. HDR is shown as supported when the display and operating system are in HDR mode; wide gamut (Display P3) is common on Apple devices and recent phones and monitors.

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