Screen / Dead Pixel is a free device test tool that runs entirely in your browser — full-screen fields to spot dead pixels. No upload, no account, no limits.
Fill your screen with solid color fields to hunt for dead and stuck pixels. Tap a color to go full-screen, then click or press the arrow keys to cycle through white, black, the primaries and the secondaries.
Against a flat field, faults are easy to spot: a pixel that stays black on every color is dead, while one stuck on a single color shows up clearly against its opposites.
A dead pixel stays black on all colors; a stuck pixel stays lit on one color. Stuck pixels sometimes recover; dead ones usually don't.
Press Esc, or use the ✕ button in the corner of the full-screen view.
Every calculation happens on this page, in your own browser. Your input is never sent to a server, never logged and never used for training — which also means the tool keeps working when you are offline.