This test generates fake dead pixels on displays, to help you understand what malfunctioning pixels look like. Stuck pixels are dots of colors that fail to refresh properly.

This can help assist purchases and product returns (RMA), especially computer monitors, displays, televisions, B-stock, or other screens with defective pixels.

Most dead pixels usually become invisible at the desktop (white backgrounds), but become more visible in dark backgrounds such as in video games.

For more information, see Defective Pixels (Wikipedia). For small chance at fixing real dead pixels, try JScreenFix.