Web guide
How to check screen resolution
A browser can report the total and available dimensions of the current screen in CSS pixels. These values are useful for diagnostics, but they are not always the display panel's native hardware resolution.
Check screen resolutionQuick steps
- Open the Screen Resolution Checker on the display you want to inspect.
- Read the reported screen width and height.
- Compare the available width and height.
- Move the browser to another monitor or rotate the device if needed.
- Pause live updates before copying a snapshot.
Total screen versus available screen
| Measurement | What it describes |
|---|---|
| Screen width and height | The browser-reported dimensions of the current display in CSS pixels |
| Available width and height | Space available for windows after system interface areas, when exposed |
| Viewport width and height | The page area inside the browser, measured by a different tool |
A taskbar, dock, or other operating-system interface can make the available height smaller than the total screen height.
Why the result may differ from display settings
Operating-system display scaling can make the browser report fewer CSS pixels than the physical pixel grid. Browser privacy protections may also reduce or alter precision. For that reason, a result such as 1536 by 864 does not necessarily mean the panel contains exactly that many hardware pixels.
Example: a high-density panel can have a native resolution of 3072 by 1728 while the browser reports a 1536 by 864 CSS-pixel screen under 200% effective scaling.
Screen resolution is not viewport size
Screen dimensions describe the display. Viewport dimensions describe the area available to the web page inside the browser. Resizing the window usually changes the viewport without changing the screen. For responsive layout testing, use the Viewport Size Checker.
Get a reliable comparison
- Record the display, operating-system scaling, browser zoom, and orientation.
- Move the window fully onto the display being tested.
- Keep CSS-pixel readings separate from native panel specifications.
- Use display settings or manufacturer specifications when native resolution is required.