Dead pixel test
Runs in this tab. Nothing is uploaded.
- Dead pixel: a black dot on white and colours.
- Stuck pixel: one dot that stays red, green or blue.
- Dust moves or blurs when you wipe; a pixel stays sharp.
How to use this tool
Fill the screen with solid colours to find dead, stuck or hot pixels. Nothing is uploaded.
Clean the screen
Wipe the screen first so dust is not mistaken for a pixel. Preview a colour with the swatches.
Start the full screen test
Press Start full screen test. Click, Space or → moves to the next colour; ← goes back.
Look at every colour
Look closely at each colour: a dot that stays black, white or one colour is a bad pixel. Esc or × closes the test.
FAQ
How do I check for dead pixels?
Clean the screen, press Start full screen test and look closely at each colour. A dead pixel stays black on white, a stuck pixel stays one colour (often red, green or blue), and a hot pixel stays white on black.
Dead pixel or dust?
Dust and smudges move or blur when you wipe the screen or change your viewing angle; a bad pixel stays sharp in the same spot on every colour it should change on.
Can a stuck pixel be fixed?
Sometimes: a stuck pixel can come back after hours of normal use. Dead pixels usually stay. This page does not flash colours quickly, which can trigger seizures.
How do I move between colours?
Click or tap, or press Space or →, for the next colour; ← goes back. Tap the left third of a touch screen to go back. Esc or × closes the test.
Does it work on phones?
Yes. Where full screen is not available (iPhone), the colour covers the whole browser window; hide the toolbars by scrolling or turning the phone.