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About this tool
See your screen resolution in CSS and physical pixels, plus viewport size, pixel ratio, aspect ratio, colour depth and refresh rate, updated live.
The What Is My Screen Resolution reads your display straight from the browser: screen.width and screen.height give the resolution in CSS pixels, and multiplying by window.devicePixelRatio gives the physical pixels your panel actually has. It also shows the live viewport and window size as you resize, the usable area after the taskbar or dock, colour depth, orientation, colour gamut and HDR support, and an estimated refresh rate measured from animation-frame timing. Enter your screen's diagonal to get pixels per inch, compare your display with common resolutions from 720p to 8K, and copy a one-click report. Nothing is sent anywhere.
Open What Is My Screen Resolution on AltFTool — it loads instantly in your browser.
Open the page at 100% browser zoom: the big figure is the Screen resolution in CSS pixels and the line below it gives Physical pixels and the pixel ratio.
Resize the browser window and watch the Viewport and Browser window tiles update; the diagram shows the window and viewport inside your screen.
Type your screen diagonal in inches under Pixel density (PPI) to calculate pixels per inch and dot pitch in mm, or press List all screens to see every monitor.
Press Copy report or Download .txt to share all figures, and check the Common screen resolutions table where your match is labelled Yours.
Operating-system scaling makes a 2880 × 1800 panel report 1440 × 900 to websites. Both figures are shown, with the pixel ratio that links them, so you know which number a form or spec sheet means.
Viewport, window, zoom-driven pixel ratio and orientation update instantly, so you can drag a window to an exact width or test responsive breakpoints.
Colour depth, colour gamut, HDR, refresh rate, usable area, PPI and a multi-monitor list where the browser allows it — the details a hardware or design question usually needs.
| Name | Resolution (px) | Aspect ratio |
|---|---|---|
| HD (720p) | 1280 × 720 | 16:9 |
| WXGA | 1366 × 768 | ≈ 16:9 |
| HD+ | 1600 × 900 | 16:9 |
| Full HD (1080p) | 1920 × 1080 | 16:9 |
| WUXGA | 1920 × 1200 | 16:10 |
| UW-FHD | 2560 × 1080 | ≈ 21:9 |
| QHD (1440p) | 2560 × 1440 | 16:9 |
| WQXGA | 2560 × 1600 | 16:10 |
| UWQHD | 3440 × 1440 | ≈ 21:9 |
| 4K UHD (2160p) | 3840 × 2160 | 16:9 |
| 5K | 5120 × 2880 | 16:9 |
| 8K UHD | 7680 × 4320 | 16:9 |
Ultrawide “21:9” panels are really 64:27 (2560 × 1080) or 43:18 (3440 × 1440); the marketing name rounds them.
Open this page and read the large figure at the top: that is your screen resolution as the browser sees it. On Windows you can confirm it under Settings › System › Display › Display resolution; on a Mac, under System Settings › Displays. The physical pixels line shows the panel's native resolution when scaling is applied.
Your operating system is scaling the display. With 150% scaling on a 1920 × 1080 laptop, websites see 1280 × 720 CSS pixels and a device pixel ratio of 1.5. Multiply the CSS resolution by the pixel ratio to get the physical resolution, which this page shows on the line below the main figure.
Device pixel ratio (DPR) is how many physical screen pixels make up one CSS pixel. A standard monitor at 100% scaling has a DPR of 1; a MacBook Retina display is usually 2; many phones are 2.5 to 3. Browser zoom changes it too, so zoom in to 110% and the ratio rises by the same factor.
Screen resolution is the size of the whole display. The viewport is the area inside the browser window where a web page is drawn, which is smaller because of the window frame, tabs, toolbars and possibly a scrollbar. Responsive websites react to the viewport, not the screen, so designers usually need the viewport figure.
For desktop and laptop screens, 1920 × 1080 (Full HD) has been the most widely used resolution for years, followed by 1366 × 768 on budget laptops and 2560 × 1440 on larger monitors. Phones report much smaller CSS sizes, typically 360 to 430 pixels wide, because of their high pixel ratio.
Yes. 1080p, Full HD and FHD all mean 1920 × 1080 pixels at a 16:9 aspect ratio. Similarly 1440p or QHD is 2560 × 1440, and 4K UHD is 3840 × 2160, which has exactly four times the pixels of 1080p.
It is an estimate. The page times about 1.5 seconds of animation frames and rounds the median interval to the nearest standard rate such as 60, 120 or 144 Hz. Battery saver, a background tab or a busy computer can make it read low; press Measure again with the tab in focus for a better result.
Colour depth is the number of bits used per pixel across red, green and blue. 24-bit means 8 bits per channel, about 16.7 million colours, which is standard. 30-bit means 10 bits per channel, used by HDR and professional displays. Browsers often report 24 even on 10-bit panels unless HDR is active.
Pixels per inch is the diagonal resolution in pixels divided by the diagonal size in inches: √(width² + height²) ÷ diagonal. A 27-inch 2560 × 1440 monitor is about 109 PPI, and a 15.6-inch Full HD laptop about 141 PPI. Enter your diagonal in the PPI box and the page uses your physical pixels.
The figures always describe the screen the browser window is currently on; drag the window to another monitor and they update. In Chrome and Edge on desktop, List all screens uses the Window Management API to show every connected display after you grant permission.