Screen Resolution Test
See your screen resolution, viewport size, pixel ratio and color depth instantly.
Reading your display…
Your test runs locally in your browser. No device data is uploaded.
How to use the screen resolution test
The values are read automatically. Resize the window or move it to another monitor to see them update.
What this test checks
Screen resolution is the full size of your display, while the viewport is the visible area inside the browser window.
The pixel ratio shows how many physical pixels make up one CSS pixel, which is why a high-DPI laptop reports a smaller logical resolution than its panel.
Color depth indicates how many bits per pixel the display reports.
Common screen resolution problems
A resolution lower than your monitor's rating usually means the wrong display mode, an old cable or a graphics driver limitation.
Frequently asked questions
- What is the difference between screen resolution and viewport size?
- Screen resolution is the whole display. The viewport is the part of it your browser window is currently showing a page in, so it is always smaller — it excludes the browser's own interface, and shrinks further if the window is not maximised.
- What does device pixel ratio mean?
- How many physical pixels the display uses for one CSS pixel. A ratio of 1 is a conventional display; 2 or 3 means a high-density screen, which is why a phone reporting 390 pixels wide still looks sharp. A non-integer value such as 1.25 or 1.5 usually means desktop scaling is enabled.
- Why is my reported resolution lower than my monitor's?
- The display is not running at its native resolution, or scaling is applied. A 4K monitor set to 1080p will report 1080p, and a scaled desktop reports a smaller logical size with a pixel ratio above 1. Both make the picture softer than the panel is capable of.
- Does this show the resolution of all my monitors?
- No. It reports the display holding the browser window. Move the window to another monitor and reload to check that one.