Dead pixel test

A dead pixel is permanently black because it gets no power. A stuck pixel is permanently lit in one colour. Stuck pixels can sometimes be fixed, dead ones usually cannot.

Often yes. Try the stuck pixel fixer, which flashes the area rapidly, and gently massage the spot with a soft cloth if it persists.

Auto mode changes colour at a slow, safe default. Fast flashing can trigger seizures in people with photosensitive epilepsy, so the speed is limited and shows a warning.

Run the test, then cycle the screen through solid red, green, blue, white and black. A stuck pixel stays a single bright colour (often red, green or blue) on a different background. Look closely from a short distance, in a dim room, and clean the screen first so dust does not look like a pixel.

That depends on the manufacturer's policy. Many brands accept one or two dead pixels as normal, and only replace a screen with more, or with dead pixels in the centre. Some retailers and premium lines have stricter rules. Check your warranty terms and test the screen as soon as you buy it, so you can return it within the return window.

Open the dead pixel test in your browser, go full screen and step through the solid colours. A dead pixel shows as a black dot on bright colours, a stuck pixel as a coloured dot on a different background. It works with monitors, laptops, TVs and phones.

Open this page on your phone, turn up the brightness and tap to move through the full screen colours. Look for any dot that does not change with the rest of the screen. Remove the screen protector if it is hard to tell. Use the stuck pixel fixer if you find a stuck pixel.