How to use it
- Open this page on the device you want to check.
- Read the values shown above; they update when you resize the window or rotate the device.
- Use the physical resolution to compare with your display's specs.
What the numbers mean
| Value | Meaning |
|---|---|
| Screen size (CSS pixels) | The size the browser uses for layout, for example 1440 × 900 |
| Physical resolution (estimated) | CSS pixels × device pixel ratio, close to the panel's real pixel count |
| Device pixel ratio (DPR) | How many physical pixels make up one CSS pixel |
| Browser window | The current size of the visible page area |
| Color depth | Bits per pixel the display reports, usually 24 |
| Orientation | Portrait or landscape |
The physical resolution is an estimate. On computers with display scaling turned on, or when the browser is zoomed, the browser reports slightly different values. For the exact panel resolution, check your system display settings.
Why CSS pixels and real pixels differ
High-density screens, such as Retina MacBooks, most phones and many Windows laptops, pack two, three or more physical pixels into each "CSS pixel". This keeps text a readable size while making it sharper.
Example: a phone that reports a screen of 390 × 844 CSS pixels with a device pixel ratio of 3 has a physical resolution of about 1170 × 2532 pixels.
On Windows, a 1920 × 1080 laptop set to 125% scaling reports 1536 × 864 CSS pixels and a DPR of 1.25. On a Mac, the DPR is usually 2 on Retina displays.
Browser zoom also changes the DPR: zooming to 110% increases the reported ratio by about 10%. Reset the zoom to 100% (Ctrl+0 or Cmd+0) for accurate numbers.
When you need to know your resolution
- Choosing wallpapers that fit your screen exactly.
- Designing and testing websites for different screen sizes.
- Buying a monitor or comparing with a new laptop.
- Gaming and video settings, which work best at the display's native resolution.
- Helping tech support, which often asks for screen size and browser window size.
- Making screenshots or presentations at the right size.
Common resolutions: 1366 × 768 (older laptops), 1920 × 1080 (Full HD), 2560 × 1440 (QHD), 3840 × 2160 (4K UHD).
Multiple monitors: the page reports the screen the browser window is on. Drag the window to another monitor and the values update, so you can check each display in turn.
Screen vs. window: web designers usually care most about the browser window size, because that is the space a page actually gets. It is smaller than the screen because of toolbars, the taskbar or dock, and any window that is not maximized.
Finding the resolution in your system settings
- Windows 11 and 10: Settings > System > Display > Display resolution. The value marked (Recommended) is the native resolution. Scale is shown just above it.
- macOS: Apple menu > System Settings > Displays shows the available resolution options for each connected display. On Retina screens the options are shown as "looks like" sizes, which correspond to CSS pixels on this page.
- iPhone and Android: check the specifications of your model on the manufacturer's site; phones do not usually show the resolution in settings.
Nothing is sent anywhere: the values are read by your browser on your device and only shown on this page.
Frequently asked questions
What is my screen resolution?
The values at the top of this page show it. The physical resolution is the number to compare with your display's specifications.
Why does it show a smaller resolution than my monitor?
Display scaling or browser zoom makes the browser report CSS pixels. Multiply by the device pixel ratio, or check your system display settings.
What is device pixel ratio?
It is the number of physical pixels per CSS pixel. High-density screens have a ratio of 2 or more.
Is my screen information stored?
No. It is read and shown in your browser only.
What resolution is 1080p?
1080p (Full HD) is 1920 × 1080 pixels.
Last updated: November 12, 2026