Why show a black screen?
A full-screen black page is the darkest image your display can show, which makes it surprisingly useful:
- Backlight bleed and glow. On LCD screens, light can leak around the edges. In a dark room, black shows up patches of bleed or "IPS glow" in the corners.
- Stuck pixels. A stuck pixel stays lit in red, green, blue or white, and is easiest to spot against black.
- Cutting distraction. Put one monitor of a multi-screen setup to black when you are presenting, watching something on another screen, or just want less light in the room.
- Cleaning. Some marks, especially streaks and smears, are easier to see on a dark screen at an angle than on white.
- OLED contrast check. OLED pixels switch fully off on true black, so the screen should look the same as when it's switched off.
How to use it
- Press Start black screen or click the preview to fill your display with black.
- Press Esc, or double-click (double-tap on a phone), to exit.
- Use the sleep timer if you want the page to close on its own, and keep the screen awake if your device keeps locking.
For checking backlight bleed, turn your screen brightness up to around three quarters, switch off the room lights and look at the screen straight on from about arm's length. A little glow is normal on most LCD panels; bright, uneven patches that are visible in normal films and games are worth reporting to the seller while you're still in the returns period.
Black screen or blackout screen?
This page is best for testing and checking. If you want your screen to look switched off while your computer keeps running (to save power on an OLED, or to play music with the screen dark), the blackout screen hides the mouse pointer and every hint as quickly as possible.