Dead Pixel Test – Find Dead and Stuck Pixels on Any Screen
Fill your screen with solid colours to spot dead, stuck or hot pixels on a monitor, laptop, TV or phone — and try to revive a stuck pixel with the flashing fixer.
Click “Start full-screen test” and step through black, white, red, green, blue and more by clicking or pressing the arrow keys. A dot that never changes colour is a faulty pixel: black on every colour means dead, one bright colour means stuck. Press Esc to exit.
How to use Dead Pixel Test
- Clean the screen with a dry microfibre cloth.
- Click “Start full-screen test”.
- Click or press → to step through the colours.
- Look closely for dots that do not match the colour.
- If you find a stuck pixel, try the stuck-pixel fixer.
Dead, stuck or hot?
Every pixel on an LCD or OLED screen is made of red, green and blue sub-pixels. When one or more of them fails, you see a dot that does not match the rest of the screen.
| Type | What you see | Often fixable? |
|---|---|---|
| Dead pixel | Black on every colour | No |
| Stuck pixel | Always red, green, blue or another colour | Sometimes |
| Hot pixel | Always white or very bright | Rarely |
Dead pixels are best seen on the white screen, stuck and hot pixels on the black one. The coloured screens help you find stuck sub-pixels that only show on certain colours.
How to test properly
Run the test in a dim room and look at the screen from a normal distance, then closer. Go slowly through every colour and scan the whole screen in sections. Dust on the glass looks similar to a dead pixel; if the dot moves when you wipe the screen, it was dust. Make a note or photo of where faults are so you can show the seller.
Trying to fix a stuck pixel
A stuck pixel is often a sub-pixel that does not switch properly. Rapidly cycling colours over it can sometimes get it working again. Start the fixer, drag the flashing square over the pixel and leave it for 10–20 minutes, then check again. This does not damage the screen, but it flashes quickly — do not watch it if you are sensitive to flashing light. Dead pixels usually cannot be fixed this way.
Warranty and returns
Test every new monitor, laptop, TV and phone within the return period. Many manufacturers follow the ISO 9241-307 pixel-fault classes and only replace a screen when a certain number of faulty pixels is reached, though some brands offer a zero-dead-pixel guarantee. Check the policy before you buy, and test right away.
More screen checks
To see your resolution and pixel density, open Screen Resolution; for the refresh rate, use the Refresh Rate Test. On phones and tablets, the Touch Screen Test finds dead zones in the touch layer.
You may also find these free tools useful: Keyboard Tester, Gamepad Tester and Screen Resolution.
Frequently asked questions
How do I check for dead pixels?
Start the full-screen test and look for dots that stay black, white or one colour while the screen changes colour.
What is the difference between a dead and a stuck pixel?
A dead pixel stays black; a stuck pixel stays one colour, such as red or green.
Can a dead pixel be fixed?
Usually not. Stuck pixels can sometimes be revived with the flashing fixer.
Does the test work on phones and TVs?
Yes. Open the page in the device’s browser and use the full-screen test.
Is the stuck-pixel fixer safe?
It does not harm the screen, but it flashes rapidly; avoid it if you are sensitive to flashing light.
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