Free Backlight Bleed Test
A free backlight bleed test: pure black fullscreen for a dark room check.
Before you start
- Turn the lights off or close the curtains.
- Set screen brightness to maximum.
- Look straight at the screen from normal distance.
- Wait a few seconds for your eyes to adjust.
Your Screen Info
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Shortcuts
- F Fullscreen
- → Next screen
- ← Previous
- Esc Exit
On a phone or tablet, tap to go to the next screen.
Colour screens
Tap a colour to test it fullscreen
Custom colour
What is a backlight bleed test?
LCD screens use a backlight behind the panel. When light leaks around the edges it shows as bright patches on dark images. A backlight bleed test shows pure black and a very dark gray so those leaks are easy to see.
Use this test on a new monitor, laptop or TV, and to tell bleed apart from IPS glow and clouding. OLED screens have no backlight, so they do not have backlight bleed.
How to run the test
1
Darken the room
Turn off the lights and set brightness to maximum.
2
Start the test
Click the Start button or press F to show pure black fullscreen.
3
Check edges and corners
Look from your normal seat, then click for the dark gray screen. Press Esc to exit.
How to read your results
Bright patches at the edges
Light that stays in the same spot when you move your head is backlight bleed.
Glow that shifts with your head
A silvery glow that changes with your viewing angle is IPS glow and is normal for IPS panels.
Cloudy blotches in the middle
Uneven patches across the screen are clouding, often worse on large TVs.
Even, faint gray
A small, even glow is normal for LCD screens.
Related tests
Black Screen Test
Pure black for hot pixels and light leaks
OLED Screen Test
Burn-in, image retention and dark gray
LCD Screen Test
Bleed, evenness and pixels on LCD
Contrast Test
Black level, white level and sharp patterns
Monitor Screen Test
Check a new or used monitor
TV Screen Test
Check a TV in its browser
Frequently asked questions
Is some backlight bleed normal?
A little bleed is common on LCD and IPS screens. Large, bright patches visible in normal use may be worth a return or warranty claim.
How is backlight bleed different from IPS glow?
Bleed stays in place; IPS glow moves and changes when you change your viewing angle.
Can backlight bleed be fixed?
Sometimes slightly loosening the screws on the back of a monitor helps, but this can void the warranty. Lower brightness makes bleed less visible.
Do OLED screens have backlight bleed?
No. OLED pixels make their own light, so there is no backlight to leak.