How to use the Dead Pixel Test
- Clean your screen first so dust and smudges are not mistaken for faulty pixels.
- Press Start full-screen test or choose a color. Set screen brightness to maximum.
- Tap, click or press space to cycle through the colors. Look closely at every part of the screen on each color.
- Note any dot that stays black on a bright color, stays bright on black, or shows the wrong color. Press Esc or Exit to finish.
Dead pixels, stuck pixels and what each color reveals
A dead pixel stays black because its transistor has failed, so it stands out on white and bright colors. A stuck pixel is locked on one color, usually red, green or blue, and is easiest to see on black. A hot pixel stays white. Solid fills make all three obvious.
Run every color rather than just white and black. A pixel that is fine on white can still be stuck on green. The gradient screen helps you spot banding, and a uniform gray screen shows uneven brightness and backlight bleed along the edges.
Stuck pixels sometimes recover, but dead pixels rarely do. Check your warranty policy before you try anything yourself, because many manufacturers only replace a panel above a set number of defective pixels. To test the other half of your display, try the Touch Screen Test, and use the Screen PPI Calculator to find your pixel density.
Frequently asked questions
What is the difference between a dead pixel and a stuck pixel?
A dead pixel is permanently black and shows up on bright backgrounds. A stuck pixel is frozen on a single color such as red, green or blue and shows up on a black background. Stuck pixels can sometimes recover, dead pixels rarely do.
Does the test work on iPhone and Android?
Yes. On devices that block the browser Full Screen API, the test uses a full-page overlay instead, which still fills the display. Hide the browser toolbar by scrolling or adding the page to your home screen for the best result.
Will this test damage my screen?
No. It only displays solid colors and uses no special brightness or refresh patterns.
How many dead pixels are acceptable?
It depends on the manufacturer and panel class, and many warranty policies allow a small number. Check your warranty terms or ask the seller before making a claim.