Dead Pixel Test — Find Dead and Stuck Pixels
A dead pixel stays black on every colour; a stuck pixel shows one colour permanently; a hot pixel is always bright. Only a full-screen flat colour makes them obvious, so this test paints the whole display in each primary colour in turn and lets you step through them at your own pace.
Quick answer: Start the test, go full screen, and look at each colour carefully — especially the edges and corners where defects cluster. Step through black (find stuck bright pixels), white (find dark ones) and the three primaries. Any dot that never changes is a pixel fault; photograph it, because the pixel policy of your warranty usually depends on how many you have and where they are.
| Colours used | Black, white, red, green, blue, plus intermediate greys for subpixel faults |
|---|---|
| Best practice | Full screen, clean screen, look from about 30 cm / 12 in, then from a normal viewing distance |
| Dead vs stuck | Dead = always black; stuck = fixed colour; hot = always white — all are permanent hardware faults |
| Before you test | Clean the screen: dust and dried droplets are far more common than dead pixels |
How to run a proper dead pixel check
Clean the screen first, then dim the room lights and run each colour full screen for at least ten seconds. Defects are easiest to spot on the opposite extreme: black shows stuck-on and hot pixels, white shows dead and dim ones, and the primaries reveal subpixel faults, which look like a coloured fringe on a white background. Sweep your eyes in horizontal bands rather than staring, and check the corners — panel defects often start at the edges.
What you can and cannot fix
A truly dead pixel cannot be repaired. A stuck pixel occasionally responds to a rapid colour exercise, which the stuck-pixel mode on this page runs — it cycles colours fast in a small area, which can sometimes dislodge a pixel that is stuck on a single colour. The success rate is real but modest, and it should be attempted only if the pixel bothers you; the exercise never damages a healthy panel.
When to use this test
- A new monitor, laptop or phone arrived and you are inside the return window
- You noticed a bright dot while watching a dark scene and want to find exactly how many
- Checking a refurbished screen before accepting it
- Documenting a defect with evidence before contacting support