How to Judge It
Bleed vs. Glow
- Fixed patch → backlight bleed
- Shifts with viewing angle → IPS glow (normal)
Backlight Bleed Test
Backlight Bleed Test — Check Screen Bleeding & IPS Glow
Fill the screen with pure black and look for light leaking around the edges. A built-in 60-second timer lets your eyes adapt to the dark first — the single most important step, and the one most tests skip.
How to test for backlight bleed
Backlight bleed is light from an LCD’s backlight escaping around the edges of the panel where it should be blocked. It only shows up on dark content, so a pure black full-screen field is the way to see it. For a fair test:
- Turn your screen brightness up to maximum.
- Turn off the room lights and close the curtains.
- Start the test and wait the full 60 seconds for your eyes to dark-adapt before judging anything.
- Scan the four corners first, then the four edges, then the center.
The 60-second dark-adaptation timer matters because your eyes get dramatically more sensitive to faint light in the dark. Glances taken in the first few seconds make bleed look worse than it is; a rested eye gives an honest read.
Backlight bleed vs. IPS glow
The most common mistake is confusing IPS glow with backlight bleed. They look similar but are different things:
- IPS glow is a silvery brightening, usually in the corners, that changes as you move your head or shift viewing angle. It is a normal characteristic of IPS panels and is not a defect.
- Backlight bleed is a cloudy or bright patch that stays fixed in place regardless of your viewing angle. Small amounts are common; large, obvious patches may be a warranty issue.
The test tells you to move your head at the end for exactly this reason: light that shifts is glow, light that stays put is bleed.
Screen bleeding on Android phones and laptops
The same test works on phones and laptops. On an Android phone, set brightness to maximum, disable auto-brightness and any dark-room dimming, and run the black screen in a dark room. Phone OLED panels usually show no bleed at all because each pixel is its own light — visible glow on an OLED is a real defect. LCD phones and most laptops use edge-lit backlights and can show mild bleeding at the corners, which is normal in small amounts. Judge it the same way: a fixed patch is bleed, an angle-dependent brightening is glow.
What to do about it
A little bleed is normal and not worth worrying about. If a corner or edge has an obviously bright, fixed patch that bothers you in dark scenes, photograph it in a dark room with a second device for evidence and check it against the manufacturer’s bleed policy. See What to do next for how returns and warranties typically handle it.