Why is my physical resolution higher than the reported resolution?

High-DPI (Retina) screens use a device pixel ratio above 1, so the physical pixel count is the CSS resolution multiplied by that ratio. A 2560×1440 screen at 2× reports 5120×2880 physical pixels.

Is the screen resolution different from the browser viewport?

Yes — screen resolution is the whole display, while the viewport is just the area inside the browser window after toolbars and scrollbars. Both are shown here.

Is any of this sent to a server?

No — all values come from your own browser via the standard screen API and stay on your device.

What is device pixel ratio?

It is how many physical pixels make up one CSS pixel. A ratio of 1 means one-to-one, while 2 (common on Retina and high-DPI screens) means each CSS pixel is rendered as a 2×2 block of physical pixels for sharper text.

How do I find my aspect ratio?

It is the screen width divided by the height reduced to whole numbers. 1920 × 1080 is 16:9, 2560 × 1600 is 16:10, and the tool calculates it for you automatically.

Why does the available area differ from the full resolution?

The available area excludes space reserved by the operating system, such as the Windows taskbar or the macOS menu bar and Dock, so it is the usable area a maximised window can occupy.

Screen Resolution Checker

Screen resolution checker

Instantly see your screen resolution, the physical pixel count after the device pixel ratio, the available area excluding the taskbar, your browser viewport, aspect ratio and colour depth. It is useful for designers, QA testers and anyone reporting a display issue who needs the exact numbers.

How it works

The tool reads standard browser display properties — no measurement or upload is involved:

Value	Source
CSS resolution	`screen.width` × `screen.height`
Device pixel ratio	`window.devicePixelRatio`
Physical resolution	CSS resolution × device pixel ratio
Available area	`screen.availWidth` × `screen.availHeight`
Viewport	`window.innerWidth` × `window.innerHeight`
Colour depth	`screen.colorDepth`

The aspect ratio is the width-to-height ratio of the screen reduced to its simplest form. All values refresh live as you resize or move the window between monitors.

Example

A 14-inch Retina laptop reports a CSS resolution of 1512 × 982, a device pixel ratio of 2, and therefore a physical resolution of 3024 × 1964 — twice as many real pixels in each direction. A standard 1920 × 1080 monitor reports a ratio of 1 and a 16:9 aspect ratio.

Everything is read directly from your browser; nothing is uploaded.