Check the connection and selected device, then repeat the failed check: the page chrome remains visible.
Part of the Screen test. Run the full screen test first for a complete device check.
The page chrome remains visible Room reflections obscure the field Marked areas do not repeat
Screen bleeding test
Use a fullscreen black field and controlled brightness guidance to inspect uneven backlight areas.
Also known as: screen bleeding test, backlight bleed test, ips glow test, black screen test. Free, online, and no download required.
No permission neededNothing uploaded
Dim the room, raise display brightness and enter the black pattern.
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What the screen bleeding test checks
| Check | How it is measured | Fails when |
|---|---|---|
| Black field | A full-viewport black test pattern removes surrounding page chrome. | The browser cannot enter fullscreen. |
| Brightness step | The selected guidance level is recorded with the run. | The level changes during comparison. |
| Marked areas | Normalized coordinates retain repeatable uneven regions. | Marks move after leaving fullscreen. |
If something failed
Check the connection and selected device, then repeat the failed check: room reflections obscure the field.
Check the connection and selected device, then repeat the failed check: marked areas do not repeat.
02
How to read the result
How the screen bleeding test works
This page uses the same fullscreen and normalized-coordinate controller as the main screen tool but limits the pattern to black. A brightness guidance selector records the viewing condition without attempting to change system brightness. Clicks add or remove local markers that remain available after fullscreen exits.
What the result can establish
Run the check in a stable dark room, look from the normal seating position and compare the same area at more than one brightness guidance level.
Measurement limits
A photographed or browser-rendered result cannot quantify panel uniformity. Reflections, local dimming, camera exposure and viewing angle can create or hide uneven regions.
03
Screen bleeding test questions
How much backlight bleed is normal on an LCD panel?
Almost every edge-lit LCD shows some bleed in a dark room at high brightness, and manufacturers rarely accept a claim for slight corner glow. What matters is whether it is visible at your normal brightness, at your normal seating position, in ordinary content.
What is the difference between backlight bleed and IPS glow?
Bleed is a fixed bright patch, usually at an edge or corner, that stays put as you move. IPS glow is a wash across a corner that changes strongly with viewing angle. Move your head while the black field is up: if it shifts, it is glow.
Should I photograph the result of the black screen test?
A photo almost always exaggerates it. Camera exposure brightens dark fields far beyond what your eye sees, which is why photographed panels look far worse than they are. Judge with your eyes first and use the marks on this page to record repeatable areas.