Screen resolution
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- Physical pixels
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- Browser viewport
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- Available area
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- Pixel ratio
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- Color depth
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- Orientation
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Screen Resolution Test
Values update live as you resize or rotate. The checkerboard square should look like even gray at 100% zoom; visible stripes or moiré mean the image is being scaled.
Quick answer
What is the Screen Resolution Test?
A screen resolution test shows your screen’s resolution in pixels, plus the browser viewport, device pixel ratio and color depth. Physical resolution is the CSS size multiplied by the pixel ratio, so a 1920 × 1080 laptop at 125% scaling reports 1536 × 864 CSS pixels.
Key features
- Screen, viewport and physical resolution
- Device pixel ratio and scaling
- Color depth and orientation
- Updates live when you resize or rotate
Why use it
- Confirm you are really running 1080p, 1440p or 4K
- Check Windows or macOS scaling
- Instant, nothing to install
Built and tested by Whitson Rao
About the Screen Resolution Test
Instantly see your screen resolution, browser viewport, device pixel ratio, color depth and orientation, plus a 1-pixel pattern to confirm the browser is rendering sharply.
How to use the Screen Resolution Test
Open the page on the screen you want to check — the readings update live.
Resize the window or rotate your device to watch the viewport values change.
Press F for fullscreen to see the full viewport size.
Check the 1-pixel pattern: at native resolution and 100% zoom it should look like even, fine gray.
Common uses
Know your resolution
Quickly find the resolution to choose wallpapers or game settings.
Responsive design
Developers can check viewport and pixel ratio on real devices.
Scaling troubleshooting
Confirm whether OS scaling is changing the effective resolution.
Support requests
Share accurate display details when reporting a website bug.
Frequently asked questions
Why is the screen size smaller than my monitor’s resolution?
Browsers report sizes in CSS pixels. With 150% scaling, a 3840-pixel-wide display reports 2560. Multiply by the device pixel ratio to get physical pixels.
What is device pixel ratio?
It is the number of physical pixels per CSS pixel. A value of 2 means a high-density (Retina-style) display.
Does browser zoom change the values?
Yes. Zooming changes the viewport size and pixel ratio. Reset zoom to 100% for accurate readings.