Backlight bleed test
Fill your screen with black and near-black to spot light leaking from the edges of an LCD panel.
Click or press → for the next shade · Esc to exit
How to test for backlight bleed
- Make the room dark. Turn off the lights and close the curtains, then wait a minute for your eyes to adjust.
- Turn the screen brightness up to its highest setting, so any bleed is easy to see.
- Click Start test. Look at the edges and especially the corners, from straight in front of the screen and about an arm's length away.
- Click or press → to switch between black, near black and dark gray. Some bleed shows up more on the slightly lighter shades.
Tip: phone cameras exaggerate bleed a lot, especially with night mode or automatic exposure. If you photograph your screen for a warranty claim, set the exposure so the photo looks like what you actually see.
What to look for
- Backlight bleed: bright patches or "clouds" at the edges or corners that stay in the same place when you move your head.
- IPS glow: a sheen in the corners that changes or fades when you move your head. Normal for IPS screens.
- Clouding: uneven, blotchy brighter areas across the middle of the screen, more common on large TVs.
Backlight bleed test FAQ
Is some backlight bleed normal?
A little, yes. Almost every LCD screen lets a small amount of light through at the edges, and you'll usually only see it on a black screen in a dark room. It's a problem when it's bright or blotchy enough to notice in dark scenes in normal use.
What's the difference between backlight bleed and IPS glow?
Bleed stays in the same place and looks the same from any angle, usually at the edges or corners. IPS glow is a silvery or golden sheen that changes or disappears when you move your head or look straight at the screen from further away. Glow is normal for IPS panels.
Can backlight bleed be fixed?
Usually not by you. It's caused by pressure or gaps in the panel's frame. If your screen is new and the bleed bothers you, check the return or warranty policy. Avoid opening or pressing on the screen, which can make it worse and void the warranty.
Do OLED screens have backlight bleed?
No. OLED screens have no backlight, so black pixels are truly off. Bleed only affects LCD screens (including IPS, VA and TN panels). To check an OLED or any screen for faulty pixels, use the dead pixel test.
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