Check any screen for dead and stuck pixels. The test fills your display with white, black, red, green, blue, cyan, magenta and yellow, one at a time. Step through with the arrow keys or let it cycle on its own, and look closely for dots that do not match. Works on monitors, laptops, TVs and phones.
How to test for dead pixels
- Clean the screen first, so dust is not mistaken for a pixel.
- Press F for fullscreen, and let the controls fade out.
- Step through the colors with the arrow keys or Space, or turn on Auto-cycle.
- On each color, scan the screen slowly, section by section, from close up.
Dead, stuck or hot pixel?
- Dead pixel
- Always black. Easiest to see on the white screen. Usually permanent.
- Stuck pixel
- Always one color, such as red, green or blue. Most visible on black or a contrasting color. Sometimes it recovers.
- Hot pixel
- Always white or bright. Shows up clearly on the black screen.
- Dust or a mark
- Moves or wipes away. Check with a soft cloth before worrying.
What to do if you find one
Check your monitor's warranty: many makers replace a screen above a certain number of bad pixels, and some stores accept returns within a few weeks. A stuck pixel sometimes comes back after the screen has been off for a while. For backlight problems rather than pixels, use the backlight bleed test, or run every pattern in the monitor test.
Questions
Can a dead pixel be fixed?
A truly dead pixel usually cannot. A stuck pixel can sometimes recover by itself after the screen is switched off for a while.
Does it work on phones and TVs?
Yes. Open it in any browser, tap to show the controls, and use the arrows to change colors.
Why is there a banner at the top?
The ads keep the site free. Use Remove ads for free by the banner to hide them for this session while you test.
How do I go fullscreen?
Press F on a keyboard, or use the fullscreen button in the bar at the bottom. Press Esc or F again to leave. On iPhone, Safari does not allow real fullscreen, so add the page to your home screen for the cleanest view.