Backlight Bleed Test
Display a pure black screen to detect backlight bleeding, clouding, and IPS glow. Test in a dark room with brightness at 100%.
What to look for
- Backlight bleed: Bright spots along edges where the bezel presses the panel.
- Clouding: Uneven blotchy patches of light.
- IPS glow: Warm yellowish glow in corners that shifts with viewing angle.
- Test in a completely dark room for accurate results.
Testing guide
How to check backlight bleed and IPS glow
Backlight bleed, clouding, and IPS glow are easiest to see on a black screen in a dim room. This test helps separate normal viewing-angle glow from obvious edge leakage or uneven backlight pressure.
Best for
- Checking a new IPS, VA, Mini-LED, or laptop display before the return period ends.
- Finding corner glow, edge bleed, clouding, and bright patches on dark scenes.
- Comparing brightness, local dimming, and panel uniformity settings.
How to run the test
- 1Dim the room and set brightness to the level you actually use at night.
- 2Open the black screen pattern fullscreen and let your eyes adapt for a few seconds.
- 3Look for bright corners, uneven patches, or edge leaks without pushing on the panel.
- 4Move your head slightly to separate angle-dependent IPS glow from fixed backlight bleed.
How to read the result
IPS glow changes with viewing angle and is normal to some degree on IPS panels.
Backlight bleed usually stays fixed near edges or corners and can indicate panel pressure.
OLED screens do not have LCD backlight bleed, so bright patches on OLED may indicate image retention or uniformity issues instead.
Related tools and guides
Frequently asked questions
Is backlight bleed normal?
A small amount can be normal on LCD displays, but strong edge leaks or bright patches visible in normal content may justify a return or warranty claim.
Should I test at maximum brightness?
Maximum brightness exaggerates the issue. Test at your normal dark-room brightness, then briefly compare higher brightness if you need photos for support.
Do OLED monitors have backlight bleed?
No. OLED pixels emit their own light and have no backlight. Use black and gray tests on OLED for uniformity, image retention, or burn-in instead.