Dead Pixel Test
Free online dead pixel test. Cycle your screen through pure red, green, blue, white, black and gray to find dead pixels, stuck pixels and backlight bleed instantly.
What is a dead pixel?
A dead pixel is a transistor failure that leaves the pixel permanently black (or white on some panels) regardless of what the screen displays. It shows up on every pure color.
What is a stuck pixel and how is it different?
A stuck pixel has one sub-pixel locked on, so it glows red, green or blue on black and white screens but disappears on its own pure color. Cycling RGB colors makes it easy to find.
How does this test work?
It fills the screen with pure red, green, blue, white, black and gray, one color at a time, so defective pixels stand out. Auto-rotate and manual navigation are both available.
Can a stuck pixel be fixed?
Sometimes. Rapid color flashing or gentle pixel-massage tools can unstick a sub-pixel. Dead pixels are hardware failures and usually only disappear with panel replacement.
Is fullscreen mode available?
The test maximizes inside the page and tries to enter fullscreen. Some embedded environments block fullscreen; in that case the test still covers the whole frame and Esc exits.
What is backlight bleed?
Uneven luminance around panel edges, seen as brighter patches on dark screens in a dim room. Minor bleed is normal for LCD technology; strong uniform glow suggests a defect.
Is any software installed or data uploaded?
No. The test is a pure browser page that switches background colors. Nothing is installed, nothing leaves your device.
How long should I run the test?
One or two minutes is usually enough: scan each color slowly at normal brightness. Checking in a dim room against black and gray reveals bleed best.
How to Use Dead Pixel Test
This test cycles your screen through pure red, green, blue, white, black and gray so that dead pixels, stuck pixels and backlight bleed become easy to spot. It runs entirely in your browser — nothing is installed or uploaded.
- Pick a starting color from the swatches, or use the custom color picker for any tone you like.
- Optionally enable Auto cycle and choose a 3, 5 or 10 second interval so the colors rotate on their own.
- Press Start test: the colors fill your screen, tool controls are hidden, and the browser tries to go fullscreen (Esc always exits).
- Slowly sweep your eyes across each full-color screen, looking for fixed dark points, constant red/green/blue dots, or uneven glow at the edges.
- Use the on-screen Next button, a click, or the arrow keys to change colors, and Exit when finished.
Dim the room lights and set your screen brightness to a high but comfortable level — dead pixels and backlight bleed are much easier to see against a dark room and a pure color.
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