Black Screen Test
Display a full-screen black field to check backlight bleed, IPS glow, and stuck bright pixels.
Test interface
Your browser may ask for permission after you press Start.Click the screen to show this hint again. Press Escape to exit.
How to use this tool
- Dim the room lights for the most useful inspection.
- Click Start black screen to enter full screen.
- Move closer and check the corners and edges for light leakage or glowing patches.
- Tap or press Escape to reveal the exit control, then leave full screen.
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Technical explanation
A black field is the standard way to inspect LCD backlight bleed and IPS glow. On an OLED panel, true black pixels are off, so any visible glow is more likely reflection or a panel fault.
The page cannot measure luminance. What you see depends on room lighting, viewing angle, and the panel type. A small amount of glow is normal for many LCDs and is not automatically a defect.
Troubleshooting
The screen is not truly black
Check for HDR mode, local dimming, ambient light sensors, and screen reflections. Some browsers render dark grey rather than true black.
Bright patches in the corners
This is commonly backlight bleed. Compare at a normal viewing angle and brightness before contacting support.
A single bright dot remains
A white dot on a black field is likely a stuck pixel. Use the Dead Pixel Test to confirm across colours.
The display turns off
Some devices dim or sleep on a black screen. Tap the screen or change the sleep setting.
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Frequently asked questions
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