Dead Pixel Tester
Flood your screen with solid colors to find dead, stuck, and hot pixels. Clean the display first, then cycle through the colors and watch for any tiny dot that doesn't belong.
← → Click anywhere or press → to change · Esc to exit
Dead pixels appear as black dots that never light up.
Stuck and hot pixels glow as bright dots — also check for backlight bleed.
A stuck sub-pixel shows the wrong color against a pure field.
How it works?
Every pixel is a red, a green, and a blue sub-pixel mixing to make one color. Flood the screen with a solid color and every pixel should show the same shade, so a faulty one breaks the uniform field and stands out. White drives all sub-pixels to full brightness, exposing dead (black) pixels; black switches them off, so a stuck or hot pixel glows against it — and also reveals backlight bleed, the uneven glow leaking from an LCD panel's edges. Pure red, green, and blue each light one sub-pixel at a time to catch one stuck on or refusing to light.
Dead, stuck, and hot pixels
Three defects behave differently, which is why cycling the colors catches all of them:
| Type | Behavior | Spot it on | Fixable? |
|---|---|---|---|
| Dead | No power — stays black on every color | White screen | Almost never — a broken transistor |
| Stuck | Frozen on one color, whatever should show | Red · green · blue | Sometimes |
| Hot | Permanently lit bright white | Black screen | Rarely |
For an accurate test
- Clean the screen first — dust and fingerprints are the most common false alarms.
- Dim the room and view the panel straight on so glare doesn't hide a defect.
- Set your display to its native resolution so each on-screen pixel maps to one physical pixel.
- Scan slowly, then re-cycle the colors to confirm anything suspicious isn't just dirt or compression noise.