Display test
Dead Pixel Test
Cycle through fullscreen colors to find dead, stuck, bright or dark pixels. Press M to mark a defect and Esc to exit.
Use this test when checking a new or used monitor, laptop, phone or TV. Confirm physical pixel defects visually; marker coordinates use CSS pixels.
Shortcuts: ← → change color · M mark defects · H hide controls · Esc exit
Dead pixel test FAQ
How do I check for dead pixels?
Enter fullscreen mode and inspect black, white, red, green and blue backgrounds. A faulty pixel remains fixed in the same position across colors.
How do I mark a faulty pixel?
Press M to enable marker mode, then select the defect. Coordinates appear below and remain only on your device.