Dead Pixel Test

A dead or stuck pixel is easy to miss on a busy picture and impossible to miss on a single solid color. This test fills the whole screen with black, white, red, green, blue and other pure colors, one at a time, so you can inspect a new monitor, laptop or phone before the return period ends.

Your screen: —

Or start with a color:
In the test: click or → for the next color, ← for the previous one, Esc to exit.

How to use it

  1. Clean the screen first, so dust is not mistaken for a pixel, and turn the brightness up.
  2. Click Start the test and go through every color, looking closely at the whole screen.
  3. A dot that stays black on white is a dead pixel; a dot with the wrong color on black or another color is a stuck pixel. On the black screen, look at the edges for backlight bleed.

Frequently asked questions

What is the difference between a dead pixel and a stuck pixel?
A dead pixel gets no power and stays dark on every color, most visible on white. A stuck pixel has one or more sub-pixels always on, so it shows as a red, green, blue or other colored dot, most visible on black. A hot pixel is always fully white.

Is one dead pixel covered by the warranty?
It depends on the brand. Many manufacturers follow the pixel fault classes of the ISO 9241-307 standard, which allow a few defective pixels, while some promise zero dead pixels. Check the policy of your brand and test a new screen during the return period.

Does this test work on phones and TVs?
Yes. Open the page in the device's browser and start the test; on phones, tap to change color. If the browser does not allow full screen, the color still covers the whole page.

✨ Stuck Pixel Fixer
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📷 Webcam Test
Wikipedia — Defective pixel