Dead Pixel Test
Find dead or stuck pixels and backlight bleed with full-screen solid colours and test patterns. Great for checking new monitors, phones and TVs. Free.
- Dead pixel: stays black on every colour.
- Stuck pixel: stays one fixed colour (often red, green or blue).
- Backlight bleed: uneven brightness, most visible on the black screen.
About Dead Pixel Test
The Dead Pixel Test fills your entire screen with solid colors (red, green, blue, white, black, cyan, magenta, gray and a gradient), so defective pixels have nowhere to hide. A pixel that stays black on every color is dead; one that glows a single fixed color (often pure red, green or blue) is stuck; and uneven brightness around the edges of the black screen is backlight bleed.
Cycling through the full color set matters because each solid color isolates different sub-pixels: a dead red sub-pixel is invisible on blue but obvious on red and white. Use the arrow keys or the on-screen buttons to switch colors, enable auto-cycle to step through them hands-free, and click, tap or press Esc to exit full-screen.
The test is ideal for inspecting a brand-new monitor, laptop, phone or TV while it is still returnable, or for documenting a defect before a warranty claim. It runs entirely in the browser on any device with a screen, nothing is installed and nothing leaves your machine.
How to use Dead Pixel Test
- Clean your screen first so dust specks aren’t mistaken for dead pixels.
- Press Start full-screen test to fill the display with the first color.
- Cycle through red, green, blue, white, black and the other colors with the arrow keys, the buttons or auto-cycle.
- Scan the whole screen slowly on each color, looking for dots that stay black or hold one fixed color.
- Check the black screen for uneven glow along edges and corners: that is backlight bleed.
- Click, tap or press Esc to exit full-screen when you’re done.