Backlight Bleed TestBacklight Bleed
Show black fullscreen in a dark room and check the edges for light leaking in.
Backlight bleed check
Dark room, full brightness · Esc to exit
Bleed check setup
- Dark room, max brightness.
- Look at edges and corners.
- View straight on, then at an angle.
Your screen
- Resolution
- --
- Viewport
- --
- Pixel ratio
- --
- Colour
- --
Shortcuts
- F fullscreen
- ←→ / click: colour
- Esc exit
IPS glow or bleed?
Glow changes with viewing angle; bleed stays put at the edges.
Check black levels →How to use
- Darken the room and set brightness to maximum.
- Press Start test and look at the edges and corners.
- Switch to grey to compare. Press Esc to exit.
How to do a backlight bleed test
This backlight bleed test shows pure black so light leaking around the edges of an LCD panel becomes visible. Turn off the lights, set brightness to your normal level, go fullscreen and look at the edges and corners.
Backlight bleed vs IPS glow
Bleed is light leaking from the edges and stays in the same place when you move your head. IPS glow changes or fades as you change your viewing angle. Clouding is uneven patches across the panel.
Can backlight bleed be reduced?
Lower the brightness, check the bezel is not pressing on the panel, and give a new monitor some time. Heavy bleed on a new product is a reason to contact the seller.
When to return a monitor or claim warranty
If the test shows a pixel that never changes, note its colour and position and take a photo with the test colour on screen. Most retailers accept returns within their own return window regardless of pixel policy, so act quickly after purchase. After that window, manufacturer warranty applies, and many brands only replace a panel once a set number or type of defects is reached. Read your exact model’s policy, and see our pixel policy and warranty guide for how the ISO pixel classes work.
Frequently asked questions
Is some backlight bleed normal?
A small amount of uneven light is common on LCD panels, especially IPS. Visible patches in normal use, with ordinary brightness, are worth reporting to the seller.
Does OLED have backlight bleed?
No. OLED pixels emit their own light and turn fully off, so there is no backlight to leak. Uneven dark areas on OLED have other causes.
How do I photograph backlight bleed fairly?
Use a dark room, set the screen to a normal brightness, and avoid long exposures, which make bleed look much worse than it is.