Dead Pixel Test
Eight solid colors fill the screen in turn. Scan the surface: a dot that stays lit or dark where it shouldn't is a defective pixel.
Click, tap or use arrow keys to switch colors. Esc exits.
How to spot defects
- Bright / stuck pixels show up best on black — look for red, green, blue or white dots that never turn off.
- Dead pixels show up best on white and bright colors — a dot that stays black everywhere is dead.
- Check at normal viewing distance, and look twice at the edges and corners where defects hide most often.
- On iPhone, Safari has no fullscreen API — the test automatically switches to a maximized window instead.
Frequently asked questions
What's the difference between dead, stuck and hot pixels?
A stuck pixel stays lit (red/green/blue/white) on dark backgrounds; a dead pixel stays black on light or colored backgrounds. Cycling pure colors exposes both kinds.
Is one or two bad pixels a defect covered by warranty?
Standards allow a small number of defects, but most brands cover bright (stuck) pixels more strictly. Test while you're still inside the return window and photograph anything you find.
Can I run this on a phone?
Yes. iPhone Safari doesn't support the Fullscreen API, so the tool falls back to a maximized-window mode — the check works the same. Raise brightness and clean the screen first.
Will this hurt the screen?
No. It's just solid colors cycling — no different from watching a video. Everything runs locally in your browser; nothing is uploaded.