How to use the Dead Pixel Test
- Wipe the screen clean, so dust isn't mistaken for a bad pixel, and turn the brightness up.
- Click Start the test. The screen goes full screen and black.
- Look closely at the whole screen, then click, tap or press → for the next color: white, red, green, blue and more.
- Note any dot that stays a different color. Press Esc when you're done.
Dead, stuck or hot?
| Type | What you see | Easiest to spot on |
|---|---|---|
| Dead pixel | A black dot that never lights up | White, red, green, blue |
| Stuck pixel | A dot stuck on red, green, blue or another bright color | Black and the other solid colors |
| Hot pixel | A white dot that's always on | Black |
Each pixel is made of red, green and blue sub-pixels, which is why a stuck pixel usually shows one of those colors. Dust on the screen moves when you wipe it, and a pixel doesn't.
Check before the return window ends
Test a new screen as soon as you unpack it, and check a used laptop, phone or monitor before you pay. Manufacturers' dead pixel policies differ: many allow a few bad pixels before they'll replace a panel, and the rules are often stricter for bright pixels and for pixels near the center. Check your warranty and the shop's return policy.
Can a stuck pixel be fixed?
Sometimes. A pixel that's stuck on a color can occasionally be revived by flashing colors over it for 10 to 30 minutes, which is what the fixer below does. Some people also gently massage the spot through a soft cloth while the screen is off, but pressing too hard can damage the panel. A dead (black) pixel usually has a failed transistor and can't be fixed in software.
Frequently asked questions
How do I test a phone or tablet?
Open this page on the device and tap Start the test. Tap anywhere to change color. On iPhone the browser bars may stay visible; rotate the phone or scroll to check the edges.
Does it work on TVs?
Yes. Open the page in the TV's browser, or show your computer on the TV, and start the test.
Is the stuck pixel fixer safe?
It just shows fast-changing colors, so it can't harm the screen. Don't use it if you're sensitive to flashing lights, and don't leave it running unattended for hours.
How many dead pixels are acceptable?
It depends on the manufacturer's policy and the screen's class. Even one bright pixel in the middle of the screen is worth reporting within the return period.