Dead Pixel Test
Fill the screen with solid colours to spot any dead or stuck pixels.
Click a colour to fill the screen, then look for any dot that stays the wrong colour. Click the screen to cycle colours, press Esc to exit.
How to use the Dead Pixel Test
- Click a colour to fill the whole screen.
- Look closely for any dot that stays the wrong colour.
- Click to cycle colours; press Esc to exit fullscreen.
About the Dead Pixel Test
The dead pixel test fills your entire screen — in fullscreen — with a series of solid colours: black, white, red, green, blue and several more. Against a flat, uniform field, a faulty pixel gives itself away. A dead pixel stays black on every colour, while a stuck pixel stays locked on one colour, such as a bright dot on a black screen, when everything around it changes. Click the screen to cycle to the next colour, and press Esc to exit.
It is the standard check when you are buying a used monitor, laptop or phone, or inspecting a brand-new panel within its return window, since a single obvious bad pixel is much easier to spot now than to argue about later.
Be realistic about what it can do: the test helps you see bad pixels, but it cannot repair them — although gently massaging a stuck (not dead) pixel sometimes coaxes it back to life. Go through every colour, because a pixel can fail on just one colour channel, and wipe the screen first, as a speck of dust can easily masquerade as a stuck pixel. See also the screen resolution checker and the mouse tester.
Frequently asked questions
What is the difference between a dead pixel and a stuck pixel?
A dead pixel receives no power and stays black on every colour. A stuck pixel is locked on a single colour, so it shows as a coloured dot that does not change when the background does.
Can this tool fix a bad pixel?
No. It only helps you find them. That said, gently massaging a stuck pixel — not a dead one — with a soft cloth sometimes coaxes it back to normal. A truly dead pixel cannot be revived this way.
Why should I cycle through all the colours?
A pixel can fail on just one of its red, green or blue channels. A fault that is invisible on one colour can stand out clearly on another, so it is worth checking every colour in the set.
I see a tiny dot — is it definitely a bad pixel?
Not always. A speck of dust or a smudge can look just like a stuck pixel. Wipe the screen with a soft cloth first, and if the dot moves or disappears it was dirt, not a pixel fault.
How do I leave the test?
Press Esc to exit fullscreen and return to the page. While in the test, clicking the screen simply cycles to the next colour.