ScreenCheckPro

Backlight bleed test

A pure black full-screen field. In a dim room, light leaking around the panel edges shows as bright patches. Here's how to judge it fairly.

Pick a level

Log what you saw

After the test, tap each zone where you saw light leaking: once for mild, twice for strong, three times to clear.

No zones marked. Tap a zone each time you see bleed there.

Set up for a fair test

  1. Dim the room, but not pitch black. Test at the light you actually use the monitor in, plus once in the dark.
  2. Brightness around 30–50%, or your everyday setting. Maximum brightness exaggerates everything.
  3. Sit where you normally sit. Looking from close up and off-centre turns IPS glow into what looks like bleed.
  4. Judge with your eyes, not a phone. Phone cameras boost exposure on black scenes and make modest bleed look dramatic.
  5. Move your head. If a corner patch changes brightness or colour as you move, it's glow; if it stays fixed, it's bleed.

Bleed, glow or clouding?

Backlight bleed: bright streaks along an edge or corner that stay put when you move. Caused by pressure on an edge-lit LCD.
IPS glow: a silvery sheen in the corners that shifts with viewing angle. Inherent to IPS; reduces with distance and room light.
Clouding: blotchy lighter patches away from the edges. Common on VA and larger LCDs; best seen on the uniformity test.
Blooming: halos around bright objects on mini-LED with local dimming. Not a defect; a limit of the number of dimming zones.

These are simplified drawings of what to look for, not photographs.

If you'd like to check blooming, turn local dimming on and use the near-black steps in the full-screen test, then move the mouse pointer across the black field: a halo that follows it is blooming.

Questions people ask

What is the difference between backlight bleed and IPS glow?

Backlight bleed is light leaking around the edges of an LCD, usually from uneven pressure of the frame on the panel. It stays the same colour and shape when you move your head. IPS glow is a silvery or orange sheen in the corners of IPS panels that changes or disappears as you change viewing angle or sit further back.

How much backlight bleed is normal?

Some bleed is common on edge-lit LCDs, especially large or curved ones. If you only see it on a black screen in a dark room at high brightness, most manufacturers consider it within tolerance. If it is visible in dark movie scenes or games at your normal brightness, many buyers return the monitor.

Can backlight bleed be fixed?

Sometimes slightly loosening the screws on the back of the panel, or gently massaging the bezel, reduces pressure-induced bleed, but it risks damage and may void warranty. Lowering brightness reduces its visibility. For a new monitor, an exchange is the safer option.

Does backlight bleed get worse or go away over time?

It rarely goes away on its own. Bleed caused by frame pressure can change slightly as a new panel warms up and settles over the first days of use, and it can get worse if the monitor is knocked or the stand flexes the panel. Test inside your return window.

Is backlight bleed covered by warranty?

It depends on the manufacturer. Many treat mild bleed as within tolerance and only accept claims for bleed visible in normal content. Photograph it at your normal brightness, not with long exposure, and check the policy for your model.

Do OLED screens have backlight bleed?

No. OLED has no backlight, so black pixels are simply off. If you see glow on an OLED's black screen, it is more likely reflection from the room or a raised black level setting.