Dead Pixel Test
Check a monitor, laptop or TV for dead and stuck pixels with full-screen color screens, plus gradient, uniformity and sharpness tests and a stuck-pixel fixer. Also shows your screen resolution.
How it works
- 1
Prepare the screen
Wipe the display and dim the room so small defects are easier to see.
- 2
Start the full-screen test
Solid colors fill the screen; move through them with a click or the arrow keys.
- 3
Look closely
Scan every area on black, white and each color for dots that don't match.
- 4
Try the fixer
For a colored stuck pixel, run the flashing fixer over it for 10–30 minutes.
Common uses
- Check a new monitor, laptop or TV within the return window.
- Inspect a second-hand screen before buying it.
- Look for backlight bleed and uneven brightness on a new panel.
About the Dead Pixel Test
Check a monitor, laptop or TV for dead and stuck pixels with full-screen color screens, plus gradient, uniformity and sharpness tests and a stuck-pixel fixer. Also shows your screen resolution.
The test uses pure full-screen colors so every red, green and blue subpixel is driven fully on or off. Screen details come from your browser: resolution is reported in CSS pixels and multiplied by the display scale to estimate the panel's native resolution, and the refresh rate is measured from animation frames.
Dead Pixel Test is part of a free, privacy-first toolkit. It uses your browser's built-in device APIs, so it starts instantly with nothing to install — and nothing you type, say or show ever leaves your device.
Because dead pixel test works without any sign-up or installation, you can use it as often as you like and it's always available — on desktop or mobile, and even offline.
Explore more device tests, or try Keyboard Tester · Webcam Test.
Related tools
Related guides
Dead Pixel Test — FAQ
A dead pixel stays black on every color because it isn't lighting at all. A stuck pixel stays lit in one color — red, green, blue or white — and can often be fixed.