Display testing
How to test a screen for dead or stuck pixels
A solid-color test makes unusual pixels easier to see. It cannot diagnose every panel fault, but it provides a reliable first visual inspection.
Prepare the display
Clean obvious dust, disable night-light filters and let the display warm up. Use normal brightness in a dim room; maximum brightness can hide subtle differences and strain your eyes.
Check five essential colors
Inspect white, black, red, green and blue in fullscreen. A black point on every color may be dead; a point fixed on one color may be stuck. Move your viewing position to rule out reflections.
Inspect uniformity
Use gray and white to look for patches, edge shading or backlight variation. Some variation is normal on consumer panels, especially near corners, so compare areas rather than expecting laboratory uniformity.
Confirm before taking action
Repeat the test after cleaning and on another input or browser. Photographing a pixel is useful for documentation, but camera moiré can create false patterns. Avoid pressing or rubbing the panel.