How to use the backlight bleed test

Darken the room and let your eyes adjust for a minute.
Set brightness to your usual level. Maximum brightness exaggerates bleed.
Press Start black screen and look at the edges and corners from straight in front.
Step through the darker grays by tapping or pressing →.
Move your head slightly. Glow that shifts with angle is IPS glow; light that stays put is bleed.

Turn off local dimming, HDR and dynamic contrast first; they can switch the backlight off on black and hide bleed.

What you see

Bleed, glow or clouding?

Light leaking around the frame, usually at the edges or corners. It stays the same when you move your head. Often caused by pressure from the bezel.

A silvery or warm glow in the corners that changes or disappears as you move. It is a property of IPS panels rather than a defect.

Blotchy, uneven patches across the screen. Common on edge-lit LCD TVs and most visible on near-black.

On mini-LED screens, halos around bright objects on black. A solid black screen won’t show it; bright content on a dark background will.

Limits

Phone cameras greatly exaggerate bleed. Judge with your eyes, and if you take a photo for a return, match the exposure to what you see.
Every LCD shows a little light on black. What counts as acceptable is set by the manufacturer’s policy, not by this test.
Local dimming, HDR and dynamic contrast can switch the backlight off on a full black screen and hide bleed. Turn them off to check the panel itself.

For single faulty pixels, use the dead pixel test. For uneven brightness on lighter shades, try the screen color test.

Test kit