Universal

Backlight-bleed testEN

Use a black field under realistic conditions, compare it with normal dark content, and avoid turning one artificial scene into a hardware verdict.

Open the isolated test runner

Backlight-bleed test

The runner is independently understandable and keeps this setup page available for reference.

I have reviewed the preparation and limitations above.

This page and any unsaved state stay open.

Inside the runner, fullscreen requires another explicit action.

This visual aid can reveal fixed bright edge or corner patterns, while helping distinguish them from viewing-angle-dependent glow.

Use a comfortably dark room and normal working brightness; sit straight in front of the display.
Open the runner in a new tab, then enter fullscreen separately if useful.
Start with black, compare the manual 5% grey field, change viewing angle slightly, and check ordinary dark content.

Input: Pure black viewed straight on, then the same screen from a slightly different angle
Output: A fixed edge patch may suggest bleed; a shifting patch may be viewing-angle glow

A camera’s exposure can exaggerate both and is not used for a severity score.

The runner shows pure black or 5% grey only after a deliberate selection.
No automatic colour change, grading algorithm, camera capture or hardware reading is used.
Fullscreen remains optional and has visible exit controls.

Panel technology, brightness, local dimming, viewing angle and ambient light materially change appearance.
IPS glow and backlight bleed are not reliably separated by this browser page alone.
The test cannot determine severity, repair need, seller policy or warranty eligibility.

No camera, screen-capture API, upload, account or saved score is used.