Defpix - Defective (dead) pixels tester is a free program that can help you with checking for defective pixels on your LCD screen. The program simply shows these colors - red, green, blue, white and black - over the whole surface of the screen. Defpix requires no installation and supports multiple monitor systems.

Defective pixels are pixels on an LCD screen not performing as expected. The pixel is failing to reproduce light levels correctly. There are three different types of defective pixels:

Hot pixels (always on).

Dead pixels (always off).

Stuck pixels (one or more sub-pixels are always on or always off).