Dead pixel test: is every pixel on your screen working?
Fill your whole screen with one colour at a time and look closely. A dot that stays black, white or one bright colour while everything around it changes is a dead or stuck pixel.
Or jump to one colour:
Wipe the screen first: dust looks like a dead pixel. Click or tap the left side of the screen to go back one colour.
How to check your screen for dead pixels
Wipe the screen with a dry microfibre cloth first, because dust and smudges look exactly like faulty pixels. Then press “Start full-screen test” and step through the colours with a click or the arrow keys. Look slowly across the whole screen, edge to edge, from normal viewing distance.
Each colour reveals a different fault. On black, look for dots that glow. On white, look for dark dots. Red, green and blue each test one part of every pixel, so a dot that is missing only on one of them is a faulty subpixel.
Dead, stuck or hot: what's the difference?
A dead pixel gets no power and stays black on every colour. It's easiest to see on white. A stuck pixel is lit in one colour, such as red or green, and doesn't change; it shows best on black. A hot pixel stays white all the time.
Stuck pixels sometimes recover on their own after hours of normal use. Dead pixels almost never come back, because the transistor that drives them has failed. On OLED screens (many phones and newer TVs), the gray screen also shows burn-in: faint shapes left over from things shown for a long time.
Warranty and returns
Many screen makers follow a pixel policy based on ISO standards that allows a small number of faulty pixels before a screen counts as defective. The exact limit depends on the brand, the screen size and sometimes the position of the pixel, so read your warranty terms.
If you just bought the screen, test it right away: many shops accept returns for any reason in the first days or weeks. Take a photo of the faulty pixel on the colour where it is most visible, with the counter in the corner, to show support.
Questions & answers
Can a stuck pixel be fixed?
Sometimes. Turn the screen off and press very gently on the spot through a soft cloth for a few seconds, or simply keep using the screen for a few days. A dead (always black) pixel can't be fixed at home.
Why is there no flashing pixel fixer here?
Fast-flashing colours can trigger seizures in people with photosensitive epilepsy, and there is little proof they work. We decided to leave them out.
Does the test work on a phone?
Yes. Tap to change colour and tap the left side to go back. If your phone doesn't allow real full screen, the test still covers the whole browser window, so check the edges with a second colour too.
Is one dead pixel normal?
On a large, high-resolution screen, one faulty pixel is within many makers' tolerance. Whether it bothers you depends on where it is: one near the centre is much more noticeable.
Can the test damage my screen?
No. It only shows plain colours, the same as any picture or video.