FreeHow the backlight bleed test works
Most LCD screens are lit by a backlight behind the panel. When the panel shows black, it should block all of that light. If the frame presses unevenly on the panel, light escapes at the edges and shows up as brighter patches on a black image: that's backlight bleed. The test switches between pure black and two very dark greys, which helps show uneven patches across the middle of the screen too, known as clouding.
Bleed, glow or normal?
- Backlight bleed stays in the same place and keeps the same shape when you move your head. Usually seen at the edges and corners.
- IPS glow changes or fades as you move your head or step back. It's a normal trait of IPS panels, not a fault.
- Clouding shows as blotchy, uneven patches across the middle, best seen on the dark grey screens.
- OLED screens have no backlight, so they should show perfect black with no bleed at all.
Found bleed? What to do
- Check it at normal brightness. Bleed you only see at full brightness in a dark room rarely shows in daily use.
- Take a photo with your phone camera set to a short exposure, so it shows what your eyes see rather than exaggerating it.
- Contact the seller while the return window is open if the bleed bothers you in normal use.
Frequently asked questions
Can backlight bleed be fixed?
Sometimes slightly loosening the screws around a monitor's frame helps, but it can void your warranty. A replacement is usually the safer route.
Does bleed get worse over time?
It usually stays the same, and can even improve slightly over the first few weeks of use as the panel settles.