Guided screen tool

Backlight Bleed Test for LCD and IPS Displays

Inspect black, 5% gray, and 20% gray fields, record affected regions, and compare how the glow changes with viewing angle.

This tool runs locally in your browser. Your marks, observations, and timing samples are not uploaded.

  1. Set up
  2. View dark fields
  3. Compare observations
  4. Review result

Dark-field observation

Use your normal viewing brightness and compare fixed edge light with angle-dependent glow.

Set realistic viewing conditions

Choose the closest panel type and room lighting. You do not need a completely dark room or maximum brightness.

Before showing the fields

  • Keep the display near your normal viewing brightness; maximum brightness can exaggerate what you see.
  • Sit at your usual viewing position and keep the screen facing you directly at first.
  • Judge with your eyes first. Phone camera auto-exposure often makes dark-screen glow look stronger.

Backlight bleed, IPS glow, and clouding

Backlight bleed usually appears as fixed light near an LCD edge. IPS glow changes with position and viewing angle. Clouding is broader uneven brightness. More than one effect can appear at the same time.

What this test cannot prove

This test cannot measure luminance, uniformity percentages, or warranty thresholds. Room light, brightness, viewing angle, camera exposure, and panel type all affect the result.

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