How the dead pixel test works
Each screen fills your entire display with a single pure color at maximum brightness. Dead pixels appear as dark spots on light backgrounds because the pixel cannot turn on. Stuck pixels appear as bright colored dots on dark backgrounds because a sub-pixel is permanently lit. Testing all five colors (white, black, red, green, blue) gives you complete coverage of all possible pixel defects.
Run a dead pixel test when unboxing a new monitor or laptop (most manufacturers have a dead pixel return policy within 14-30 days), after a screen repair, or if you notice any visual anomalies during normal use.
Run a dead pixel test when unboxing a new monitor or laptop (most manufacturers have a dead pixel return policy within 14-30 days), after a screen repair, or if you notice any visual anomalies during normal use. Regular testing is especially important for displays used in photography, video editing and design work where pixel accuracy matters.
What to do if you find dead pixels
Document the location and type (dead vs stuck) with a photo. For new devices, contact the manufacturer — most have warranty policies covering pixel defects above a threshold count. For stuck pixels, try the color-cycling method: display rapidly alternating colors on the affected area for 30-60 minutes. Dead pixels are hardware failures and typically require screen replacement.
When to test and what to do with results
Test new monitors within the manufacturer's return window (usually 14-30 days). Most brands have a dead pixel policy — they will replace the monitor if the number of defective pixels exceeds a threshold, typically 3-5 bright or dark subpixels. Document defects by taking a close-up photo showing the pixel on a solid-color background, noting its approximate location on the screen. For used or refurbished monitors, test immediately upon receiving to establish a baseline.