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Reading your display information…
Device check
Screen Resolution Test
See your reported screen size, viewport, pixel ratio, color depth and orientation in one clear report.
✓ Instant result✓ No sign-up✓ Runs in your browser
01
How to use this test
- Open the test on the display you want to inspect.
- Read the reported screen, viewport and pixel-ratio values.
- Resize the window or rotate your device to see the measurements update.
02
If something looks wrong
- Browser zoom and operating-system scaling can change reported CSS dimensions.
- Move the browser window to the correct monitor before comparing values.
- Use the display settings in your operating system to confirm the selected resolution.
What the result means
The browser reports layout pixels, physical-pixel ratio and available space.
Screen resolution is not one number in a modern browser. The page can report the screen dimensions used for layout, the current viewport and the device-pixel ratio that maps CSS pixels to display pixels. Together they explain why a high-density phone or laptop may show smaller browser dimensions than the panel's advertised native resolution.
Zoom, display scaling, browser sidebars, operating-system bars and multi-monitor placement affect what a web page sees. Full-screen mode can increase the available viewport but does not change the panel itself. Use the reported values to troubleshoot layouts, screenshots and scaling, not to identify the display model.
Reading the signal
Separate screen size, viewport and pixel density.
Screen dimensions
These are browser-reported CSS-pixel dimensions for the active screen and may already include operating-system scaling.
Viewport
This is the usable page area inside the current browser window. It changes as the window, browser chrome or side panels change.
Device-pixel ratio
A value above one means each CSS pixel maps to multiple physical pixels or a scaling transformation.
Available area
This can exclude operating-system taskbars or reserved regions and is therefore often smaller than the full reported screen.
Browser-test limits
Privacy protections and browser abstractions can round or transform display values. The page cannot reliably read the panel's exact physical pixel grid, dimensions, color depth quality, HDR performance or model name.
Read our complete testing methodology →Troubleshooting
From symptom to next step.
What you seeLikely causeWhat to try
Resolution looks lower than advertisedDisplay scaling or a device-pixel ratio is converting physical pixels into larger CSS layout pixels.Compare the ratio and operating-system display settings; do not multiply values unless you specifically need an approximate physical-pixel count.
Viewport changes unexpectedlyBrowser bars, zoom, side panels, the on-screen keyboard or window resizing changed usable space.Reset browser zoom, close panels, enter full screen if appropriate and measure again in the intended window state.
Wrong monitor seems detectedThe browser window may straddle displays or remain associated with the previous screen.Move the whole window onto the target display, wait briefly and reload the test.
Quick answers
Good to know.
Why is the reported size lower than my monitor resolution?+
Browsers often report CSS pixels after display scaling. The physical-pixel estimate combines that value with the device pixel ratio, but hardware reporting still varies.
What is device pixel ratio?+
It describes how many device pixels are used for one CSS pixel. High-density displays commonly use a value greater than one.
Why is a 4K display not reported as 3840 × 2160?+
At 200% scaling, browsers commonly expose a 1920 × 1080 CSS-pixel workspace with a device-pixel ratio near two. The panel can still be 4K.
Does browser zoom change screen resolution?+
It changes page layout and viewport behavior but not the physical panel. Browser and operating-system scaling can influence the values exposed to scripts.
Can this identify my monitor model?+
No. Standard browser APIs expose display geometry, not a dependable manufacturer and model identifier.