This dead pixel test fills your entire screen with solid colours, one after another, so faulty pixels stand out clearly against a uniform background. Cycling through black, white, red, green and blue is the standard way to reveal both dead pixels, which stay black, and stuck pixels, which are frozen on a single colour. It works on monitors, laptop panels, tablets and phones, and needs nothing but a browser in full-screen mode.
A dead pixel is a pixel that receives no power and shows as a small black dot on every colour, so it is easiest to spot on a white or bright background. A stuck pixel still receives power but is frozen on one colour channel, so it shows up as a bright red, green or blue dot, most visible on a black screen. By stepping through the full set of colours and looking closely at each one, you cover both cases. For the clearest results, clean the screen first so dust and smudges are not mistaken for pixel faults, and view the panel straight on in a dimly lit room.
Dead and stuck pixels are different problems. Stuck pixels sometimes recover on their own or can be coaxed back with rapid colour changes or gentle pressure, while a truly dead pixel is usually permanent. Knowing which one you have matters when you buy a new display, since many manufacturers only honour a warranty once the number of faulty pixels crosses a stated threshold. Running this test as soon as a monitor or laptop arrives is the best way to catch a problem inside the return window.
The test runs full screen so nothing distracts from the colour field, and you advance through the colours with a click or the arrow keys, then exit at any time with a clearly marked button or the Escape key. Everything happens locally in your browser, with no downloads and no data leaving your device, which makes it a fast and safe first check for any new or second-hand screen.
How to use the dead pixel test
- Clean your screen so dust and smudges are not mistaken for faults.
- Click the start button to enter full-screen colour mode.
- Click or press the arrow keys to advance through black, white, red, green and blue.
- Look closely at each colour for dots that stay dark or show the wrong colour.
- Press the exit button or the Escape key to leave full-screen mode.
Frequently asked questions
What is the difference between a dead pixel and a stuck pixel?
A dead pixel gets no power and stays black on every colour, so it shows best on white. A stuck pixel is frozen on one colour and shows as a bright red, green or blue dot, best seen on black. Cycling through all the test colours reveals both types.
Can a stuck pixel be fixed?
Sometimes. Stuck pixels occasionally recover after rapid colour cycling or very gentle, careful pressure on the panel, though results are not guaranteed. A genuinely dead pixel, which receives no power, generally cannot be repaired.
How do I exit the full-screen test?
Press the Escape key or click the exit button shown on screen. Both return you to the normal page immediately, so you are never stuck in full-screen mode.
Does this work on a phone or tablet?
Yes. The test simply fills the screen with solid colours, so it works on any device with a browser. On a touchscreen, tap to advance through the colours instead of clicking.
More hardware tests
Keep checking your gear with the rest of the MyGearCheck suite: