Black Screen Test

By Cedrick Reese, WhitestScreen.com

This black screen test is the best way to spot stuck pixels, check backlight bleed, and reduce OLED power draw. Bright defects that hide against colorful content stand out clearly against pure black.

Is it backlight bleed, or just IPS glow?

Almost every LCD panel shows some light leakage on a full black screen. The question is whether that's normal or a defect. Here's the quick way to tell them apart:

Tilt your head left and right

Does the bright patch move as you change your viewing angle?

Moves with you → IPS glow

A normal characteristic of IPS panel technology. Not a defect.

Stays fixed → backlight bleed

A manufacturing/assembly issue. Worth checking your retailer's return policy if it bothers you.

How to use it

Darken the room if you can, since light leakage is much easier to see in low ambient light.
Tap Fullscreen and look across the whole panel, especially the edges and corners.
Run the head-tilt check above on anything you spot.
Switch to white or another color to check for the opposite defect: a dark dot on white is a dead pixel.

Saw something else?

A fixed dark or bright dot instead of a haze → Dead Pixel Test. A soft halo around a bright shape → Mini-LED Blooming Test.

Frequently asked questions

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

IPS glow shifts position as you change your viewing angle and is a normal characteristic of IPS panel technology. Backlight bleed stays fixed in the same spot no matter how you tilt your head, and is a manufacturing defect that may be worth an RMA.

Is some light leakage on a black screen normal?

Yes. Almost every LCD panel shows some light leakage on a full black screen. The question isn't whether you see any light at all. It's whether that light moves with your viewing angle (IPS glow, normal) or stays fixed (backlight bleed, a possible defect).

Can a black screen help with OLED burn-in?

Yes. On OLED and AMOLED displays, black pixels are switched off rather than dimmed, which uses less power and avoids stressing those pixels during a break from active use.

Not sure this is your actual problem? Start with the full screen defect triage guide →

This page renders a flat, dithering-free black using your browser's own canvas rendering, the same baseline used for panel-inspection checks in electronics repair. Backlight bleed and IPS glow are lighting artifacts rather than something a solid black screen measures directly, so the FAQ below explains how to tell them apart by eye, checked against current display-testing practice.

About the creator

Ready Utilities was founded by Cedrick Reese, a retired veteran and web developer who enjoys building free, user-friendly online tools that simplify everyday tasks. Read more →