What Is My Screen Resolution? Screen Size and Viewport
This page shows your screen resolution straight away: the screen size your browser reports, the real physical pixels on high-density displays, your current browser window (viewport) size, the device pixel ratio, aspect ratio and color depth. Resize your window and the numbers update live.
Everything runs in your browser. Nothing you enter is sent to or stored on our server.
Quick answer: The big number is your screen resolution as websites see it. On phones, tablets and high-DPI laptops, the real panel has more pixels; multiply by the device pixel ratio to get the physical resolution shown underneath. For example, an iPhone screen reported as 393 × 852 with a ratio of 3 has 1179 × 2556 physical pixels.
How to read your screen resolution
- Screen size (CSS pixels): the size your browser uses for layout. Web designers build for this number.
- Physical resolution: the actual number of dots on the display, such as 1920 × 1080 or 2560 × 1440.
- Viewport: the part of the browser window that shows the page, without toolbars. It changes when you resize the window.
- Device pixel ratio: how many physical pixels make up one CSS pixel. Windows display scaling of 125% or 150% and browser zoom both change it.
Common screen resolutions
| Name | Resolution | Aspect ratio |
|---|---|---|
| HD (720p) | 1280 × 720 | 16:9 |
| Laptop (common) | 1366 × 768 | 16:9 |
| Full HD (1080p) | 1920 × 1080 | 16:9 |
| WUXGA | 1920 × 1200 | 16:10 |
| QHD / 1440p | 2560 × 1440 | 16:9 |
| Ultrawide QHD | 3440 × 1440 | 21:9 |
| 4K UHD | 3840 × 2160 | 16:9 |
| Typical phone (CSS) | 360 to 430 wide | about 9:19.5 |
How to change your screen resolution
Windows 11: right-click the desktop, choose Display settings and pick a Display resolution; the recommended one matches your panel. Change Scale to make text larger without lowering sharpness. Mac: open System Settings > Displays and choose a size option. Phones and tablets do not let you change resolution, but you can change text and display size in accessibility settings.
Testing your display? Use the dead pixel test. Check other hardware with the keyboard tester and webcam test, or find your network address with what is my IP.
FAQ
Why does my 4K monitor show 1920 × 1080?
Windows or macOS is scaling the display by 200%, so websites see 1920 × 1080 CSS pixels while the panel shows 3840 × 2160 real pixels for sharper text.
Is any information stored?
No. The details are read by your browser and shown only to you.
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