Screen Test and Dead Pixel Test
Choose Manual to move through the colors yourself, or Auto to let them change on their own. Look for any dot that stays a different color from the rest of the screen.
Or tap a single color above to look at just that one. Clean your screen first, because dust and smudges look just like dead pixels.
How to run the test
Wipe the screen with a clean, dry microfibre cloth and make the room a little darker. Set your browser zoom to 100 percent, then press Start. Go through every color slowly and look at the whole screen, corners included. Black and white matter most. A pixel that stays lit on a black screen shows up instantly, and one that stays dark on a white screen is just as easy to spot.
Manual or auto?
Manual lets you stay on a color as long as you like. Click or press the arrow keys to move on. Auto changes color every few seconds (you choose from 2 to 8), which is handy when you want to sit back and watch the whole screen. Click to pause on a color, and click again to carry on. Nothing flashes quickly. The fastest setting is two seconds per color.
What you might find
- Dead pixel: a tiny black dot that never lights up. It is easiest to see on white.
- Stuck pixel: a dot stuck on one color, usually red, green or blue. It stands out on black.
- Hot pixel: a dot that stays white on every color.
- Backlight bleed: pale patches along the edges of a black screen. That's a lighting issue and not a pixel fault.
- Uneven color: a tint or darker band on the gray and gradient screens.
Found a bad pixel?
Don't panic yet. Many makers allow a few faulty pixels before they'd replace a screen, so check your warranty terms. We cover what to do next in our guide on how to check your screen for dead and stuck pixels. If you're buying a used laptop, run this test before you pay. Our second-hand laptop checklist has the rest of the checks.
Frequently asked questions
What is a dead pixel?
A dead pixel is a tiny dot on your screen that never lights up, so it always looks black. A stuck pixel stays lit in one color, such as red, green or blue.
Is the screen test safe for my display?
Yes. It only shows solid colors and simple patterns. Nothing flashes on its own, and you move to the next color yourself by clicking or pressing the arrow keys.
Does the screen test work on phones and tablets?
Yes. Tap Start, then tap the screen to move to the next color. After the last color the test closes by itself.
Can the screen test run automatically?
Yes. Choose Auto, pick how many seconds each color should stay on screen, and press Start. Click to pause, click again to resume, or press Esc to exit.
Is it a dead pixel or just dust?
Wipe the screen with a clean, dry microfibre cloth first. Dust and smudges move or disappear when you wipe, while a real pixel fault stays exactly where it is.
Also check your keys with the Keyboard Tester, or your connection with the Internet Speed Test.