Black Screen Test for Dead Pixels and Bleed
Learn when to use a fullscreen black screen, what it reveals, and how to avoid misreading normal glow as a defect.
Quick answer
A black screen test reveals bright stuck pixels, hot pixels, fixed LCD edge light and some dark-scene uniformity problems. Use normal brightness first, then compare with dark gray and solid colors so IPS glow or camera exposure is not mistaken for a defect.
Last reviewed: August 1, 2026 · Testing method and editorial policy
What black reveals best
Bright white or colored dots stand out against black. Fixed edge or corner light on an LCD can also become easier to see in a dim room.
What black cannot confirm alone
OLED burn-in may be invisible on true black because the pixels switch off. Dead dark pixels are also easier to confirm on white and primary colors.
Avoid camera exaggeration
Automatic exposure can lift black levels and make minor glow look severe. Judge with your eyes at normal settings and use photos only as supporting evidence.
How to verify it
- Set normal brightness and enter fullscreen.
- Inspect for fixed bright dots and edge light.
- Move your head slightly and compare the same areas on dark gray.
- Finish with white, red, green and blue to classify any fixed mark.