Dead Pixel Test

How to use the dead pixel test

Each color turns specific subpixels on or off across the whole screen, so a faulty pixel stands out against it. The test never changes color by itself: you move to the next color with a button, the → key, or Space in fullscreen, and stay on any color as long as you need.

1. 1

   Clean the screen first. Dust looks like a dark pixel. A speck that wipes away is not a fault.

2. 2

   Open it full screen so the edges and corners are included.

3. 3

   Scan each color slowly, one area at a time, from your usual distance.

4. 4

   Check anything you find. Move to another color and see whether the dot is still there and how its color changes.

On a phone or tablet

Touch screens have no arrow keys, and a tap on the field exits fullscreen. So on a phone or tablet, open a color full screen, look it over, tap to return, then tap the next color button and open it full screen again. Hold the screen at your normal reading distance and use your usual brightness.

Dead, stuck, or something else?

A dead pixel stays dark on every color, most visible on white. A stuck pixel stays lit in one color, most visible on black, where it shows as a red, green, blue, or white dot. A partly faulty pixel shows on some colors and not others: a pixel missing its red subpixel looks dark on red and cyan-tinted on white.

Many manufacturers accept a small number of faulty pixels as normal, and the number differs by brand and panel. Dead Pixel vs Stuck Pixel explains what each kind of dot means, and Dead Pixel Warranty Policies quotes what Dell, ASUS, LG and Apple publish. Check your own warranty or return terms before deciding what to do. For a guided run with a summary, use the Monitor Test; for single fields, the White Screen and Black Screen. How to Test a Monitor shows where this test fits in a full check.