Dead Pixel Test
Cycle fullscreen colors to find dead and stuck pixels on any screen.
Wipe your screen first — dust looks exactly like a dead pixel. In fullscreen: click, tap or use ← → to change color, Esc to exit.
Click / → next color · Esc to exit
How it works
The test fills your entire screen with a sequence of solid colors: white, black, and the pure primaries and secondaries. Each color isolates a different failure. On black, any bright dot is a stuck sub-pixel that is on when it should be off. On white, any dark dot is a dead pixel whose transistor no longer fires. On pure red, green and blue, a dot that stays dark reveals which individual sub-pixel has failed — a pixel dead only on red has a failed red sub-pixel.
Scan the whole screen slowly at each color, corners included, from about 30cm away. A dead pixel (black on all colors) is permanent hardware failure — check your panel's warranty pixel policy. A stuck pixel (frozen on one color) can sometimes be revived with gentle massage or rapid color cycling — the difference and the revival techniques are covered in our dead vs stuck pixel guide. For broader panel issues like backlight bleed or banding, continue to the monitor test suite.
Troubleshooting
› I found a pixel that is always black
A pixel dark on every color is dead — its transistor no longer drives the sub-pixels. It cannot be fixed in software. Check your warranty; many panels are covered above a defect threshold.
› I found a pixel stuck on red, green or blue
That is a stuck pixel, and unlike dead pixels these sometimes recover. Gentle massage over the spot with a soft cloth, or leaving a rapidly flashing pattern on it, occasionally revives them.
› Fullscreen won’t open
Some browsers block fullscreen requests until you interact with the page — click the start button rather than using a keyboard shortcut. On iPhone, Safari does not allow true fullscreen; scroll the browser chrome away instead.
Frequently asked questions
› What is the difference between a dead and a stuck pixel?
A dead pixel stays black on every color. A stuck pixel is frozen on one color (red, green or blue). Stuck pixels can sometimes be revived; dead ones cannot.
› Which colors should I check?
All of them. Black reveals bright/stuck pixels, white reveals dead ones, and pure red, green and blue isolate each sub-pixel.
› Does this work on phones and TVs?
Phones and tablets, yes — open this page in the device’s browser. For TVs, open the page in the TV’s browser or cast a solid-color video.
› Is one dead pixel covered by warranty?
Policies vary: many manufacturers require a minimum number of defects before replacing a panel. Check your vendor’s pixel policy — bright (stuck) pixels are often treated more strictly than dark ones.