Test your screen for dead pixels, bright spots, and backlight bleeding by displaying solid colors in fullscreen.
Click a color to test individually
Use white to detect dark/dead pixels and black to detect bright spots or backlight bleed
Red, green, and blue help identify individual sub-pixel defects
Set your screen brightness to maximum for the most accurate results
Dead pixels are pixels that remain permanently off (appear black on a white background). Stuck pixels are fixed on one color — they show as bright dots on a dark background. Hot pixels only appear after prolonged use when the display heats up. Backlight bleed appears as uneven brightness or light leaking around the edges of LCD panels, most visible on a black screen in a dark room.
LCD (Liquid Crystal Display) panels use a backlight behind liquid crystal layers. They can suffer from backlight bleed and limited contrast ratios. OLED (Organic Light-Emitting Diode) panels have self-emitting pixels — each pixel produces its own light. This means true blacks (pixel is completely off), infinite contrast ratio, and no backlight bleed. However, OLED can develop burn-in from static images displayed for long periods.
The pure red, green, and blue test colors help verify that your display's sub-pixels are working correctly. Each pixel on your screen is made up of three sub-pixels (R, G, B) that combine at various intensities to create all visible colors. Professional displays cover wider color gamuts like sRGB (99%), DCI-P3 (used in video production), and Adobe RGB (for print work).
Dead pixels don't work at all and appear black on any background. Stuck pixels are fixed showing one color (usually red, green, or blue). Dead pixels are generally permanent, while stuck pixels can sometimes be fixed by gently massaging the area or using pixel-exercising software.
Most manufacturers have a dead pixel policy. ISO 13406-2 classifies displays into quality classes. Class I allows zero defects. Many premium monitors guarantee zero dead pixels, while budget displays may allow 3-5. Check your manufacturer's warranty policy for replacements.
Yes, testing in a dark room with maximum brightness is ideal. Backlight bleed and bright spot defects are most visible on a black screen in darkness. Dead pixels are easier to spot on a white or solid-color background.