Black Screen Online – Full Screen Black
Press F to fill your screen with pure black. Lit dots are stuck or hot pixels, and light along the edges is backlight bleed or IPS glow. The backlight bleed test adds corner markers if you want to look closer.
Click to fullscreen or press F/Space
Resolution Settings
Presets
Keyboard Shortcuts: Press F or Space for fullscreen, ESC to exit
Found a stuck pixel? Try to revive it with the Dead Pixel Fixer
How to Use This Tool
What is this Test?
A full black screen (#000000) switches every subpixel off, so anything you still see is light the panel should not be producing. On an LCD monitor the backlight is always on behind the liquid crystals, which can never block it completely. That is why black is the test for backlight bleed, IPS glow, clouding and black level. It is also the best background for stuck and hot pixels: a subpixel that is permanently lit shows up as a bright red, green, blue or white dot on black. On an OLED screen, pixels really switch off, so black should look perfectly black and any lit pixel is a defect.
What a Black Screen Reveals
- Stuck and hot pixels: bright colored or white dots. These are the defects white screens miss, and the ones the Dead Pixel Fixer can sometimes repair.
- Backlight bleed: bright patches along the edges or in the corners that stay in the same place when you move your head. Caused by pressure or gaps in the panel assembly.
- IPS glow: a silvery or warm haze in the corners that changes with your viewing angle. A normal property of IPS panels, not a defect.
- Clouding: uneven, cloudy patches across the middle of the screen. Most common on large edge-lit LCD TVs.
- Black level: how grey black looks in a dark room. IPS panels typically reach a contrast of about 1000:1, VA panels 3000:1 or more, and OLED is effectively infinite.
Black Screens on OLED and Mini-LED
- OLED: black should be completely dark, with no glow or bleed. Any dot of light is a stuck subpixel. A faint vertical line or tinted band can be an early sign of panel damage.
- Mini-LED and full-array local dimming: the backlight dims zone by zone, so a black screen may look perfect while a small bright object on black shows a halo (blooming). Test with a small white cursor on the black screen.
- Idle use: a black screen does not protect an OLED panel from burn-in better than turning the display off. Use the built-in pixel refresh and screen-off features for that.
Testing Tips
- •Test in a dark room, but not with brightness at 100 percent. Maximum brightness exaggerates bleed far beyond what you will see in films or games.
- •Give your eyes a minute to adapt to the dark before you judge glow and bleed.
- •Move your head from side to side: light that changes shape is IPS glow, light that stays fixed is bleed.
- •Phone cameras greatly exaggerate bleed and glow. Use photos to document a problem, not to decide whether it is one.
- •Check the whole screen for small bright dots, including the edges hidden behind taskbars in normal use.
Keyboard Shortcuts
How this test works
The page asks your browser to show one element in full screen and colors it pure black (#000000), so every pixel is told to switch off. Any light you still see comes from the backlight or from a faulty pixel, not from the page. The Download button saves the same color as a PNG at the resolution you choose.
Pro Tip: If you find a bright dot on black, switch to the red, green and blue screens to see which subpixel is stuck, then try the Dead Pixel Fixer on that spot. For bleed, the Backlight Bleed Test adds corner markers that show you where to look and make it easier to judge how serious it is.
Frequently Asked Questions
Why isn't my black screen completely black?
On an LCD monitor the backlight stays on behind the panel, and the liquid crystals cannot block all of it. Typical IPS panels reach a contrast of around 1000:1, so black looks dark grey in a dark room. VA panels get closer to black, and OLED screens switch pixels off completely.
I see a bright dot on the black screen. What is it?
A lit dot on black is a stuck or hot pixel: a subpixel that stays on when it should be off. Switch to the red, green and blue screens to see which color it is, then try the Dead Pixel Fixer on that spot.
What is the difference between backlight bleed and IPS glow?
Backlight bleed is light leaking at the edges, and it stays in the same place when you move your head. IPS glow is a haze in the corners that changes with your viewing angle, and it is a normal property of IPS panels. The Backlight Bleed Test explains how to tell them apart.
Does a black screen save power?
On an OLED screen, yes: black pixels are switched off and use almost no power. On an LCD the backlight stays on at the same brightness, so a black screen saves little or nothing. Turning the display off is always better.
Is some backlight bleed normal?
Yes. A small amount of light at the corners, visible only on a black screen in a dark room, is normal on most LCD monitors and usually not a warranty case. Bleed you notice in films or games in a normally lit room is a stronger reason to return the monitor.
How do I get out of the black screen?
Press Esc. On a touchscreen, tap the screen and use the exit button at the bottom. If the page doesn't respond, Alt+Tab (Windows) or Cmd+Tab (Mac) switches to another window.
Written by R. Ottens, front-end developer & image editing specialist.