Guided screen tool

Dead Pixel Test Online

Inspect white, black, red, green, and blue fields, mark up to three suspect points, and record what you actually observe.

This tool runs locally in your browser. Your marks, observations, and timing samples are not uploaded.

  1. Prepare
  2. Inspect colors
  3. Review result

Guided five-color inspection

Move through each solid field manually. The tool records your marks, but it does not detect defects for you.

Prepare the screen

  • Gently clean the screen so dust or a screen protector mark is less likely to be mistaken for a pixel defect.
  • Use a comfortable, normal brightness rather than forcing the display to maximum brightness.
  • View the display from your normal working distance, then move closer only to verify a fixed point.
  • Set browser zoom to 100% and move this window to the display you want to inspect.
White
Black
Red
Green
Blue

Dead, stuck, and subpixel behavior

A full dead pixel often stays dark across bright fields. A stuck or hot subpixel may remain lit or colored on black. Partial color changes can involve a single subpixel, while dust and coating marks can mimic all three.

What this test cannot prove

The browser cannot inspect the physical panel or certify a defect. Marks use browser viewport coordinates, not hardware pixel coordinates, and a screenshot will not capture a physical dead pixel.

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Continue with a focused test only when it matches what you are trying to inspect.

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