Screen & Dead Pixels
    Display · Backlight bleed

    Backlight bleed test

    Open the black fill in full screen in a dark room. Light leaking from the edges or corners is backlight bleed, and patchy brightness is clouding.

    Loading test…

    About the backlight bleed test

    Updated

    LCD monitors light the picture from behind, and on some panels that light leaks around the edges where the panel isn't sealed evenly. It's most visible on dark scenes and in dark rooms. The backlight bleed test fills the whole screen with black, and with other solid colours and gradients, so bleed, clouding and uneven brightness stand out. OLED screens light each pixel themselves, so they don't have backlight bleed.

    How to use it

    1. Turn the room lights off and set the monitor's brightness to the level you normally use.
    2. Open the black fill in full screen.
    3. Look straight at the screen from your normal seating position and check the edges and corners.
    4. Move your head to the side: glow that shifts with your viewing angle is IPS glow, not bleed.

    Frequently asked questions

    What's the difference between backlight bleed and IPS glow?

    Bleed is light leaking at fixed spots near the edges, and it looks the same from any angle. IPS glow is a sheen that changes or moves as you shift your head, and it's normal for IPS panels.

    How much backlight bleed is normal?

    A little at the corners on a fully black screen in a dark room is common on LCDs. Bleed you can see in normal use, or in a bright room, is worth a return or warranty claim.

    Can I fix backlight bleed?

    Lowering the brightness makes it less visible. Bleed caused by pressure on the panel can ease slightly over the first weeks, but it's mostly a manufacturing issue, so test within the return window.

    Specific tests