What this can and cannot fix
This only helps a stuck pixel, which is one that is permanently lit in one or more subpixels and shows as a coloured or white dot on every screen including black. It does nothing whatsoever for a dead pixel, which receives no power and is black on every colour. Run the dead pixel test first so you know which one you have, because there is no sense spending twenty minutes on something software cannot touch.
Be honest about the odds. Rapid colour flashing frees a stuck pixel some of the time, not most of the time, and the chance drops the longer the pixel has been stuck. It is free and it does no harm, which is the entire argument for trying it.
How to run it
- Press the button to go full screen. The screen will flash red, green and blue in sequence, about six times a second.
- Leave it running for 10 to 20 minutes. Checking after thirty seconds tells you nothing.
- Check the pixel afterwards on the black screen and then on white. If it has not moved, a second run rarely helps, but a run on a different day sometimes does.
- Press Escape to stop at any time.
A warning before you start
This page flashes bright colours rapidly for a long time. If you have photosensitive epilepsy, or you are in a room with someone who does, do not run it. Point the screen away from you while it works, which is also more comfortable and costs nothing.
The pressure method, and why to be careful with it
The other common technique is gentle pressure: switch the display off, put a soft damp cloth over the stuck pixel, press very lightly with a blunt rounded object, and switch the display back on while releasing. It works occasionally on LCD panels by redistributing the liquid crystal. It also permanently damages panels when people press too hard, and it can void a warranty. If the display is still under warranty, claim on the warranty instead. If you try it anyway, use far less force than feels useful.
Do not attempt either method on an OLED panel. The mechanism is different, stuck pixels there are usually a sign of the emitter itself failing, and pressure on an OLED leaves marks that do not come out.