How to use the black screen
Press Go full screen and your whole display turns plain black. The buttons and the mouse pointer hide after a couple of seconds; move the mouse or tap to bring them back. Press Esc, or the Exit button, to leave. You can also click the preview to go full screen.
You can switch to white, red, green, blue or gray at any time, or use the arrow keys and the number keys 1 to 6 while it is open. The color only changes when you choose. Nothing is uploaded and nothing is saved.
On an iPhone, Safari doesn't let a web page take over the whole screen, so the black fills the browser window instead.
What a black screen is good for
- Backlight bleed. On an LCD, light can leak around the edges of the panel. You see it on black in a dark room.
- Glowing pixels. A stuck or hot pixel that stays lit stands out on black as a bright dot.
- Cleaning. Fingerprints and dust are easy to see on a black screen in daylight, and a dark screen is easier on the eyes while you wipe.
- A dark screen without switching off. Keep a second monitor dark during a film or a presentation, or dim a room without closing anything.
- Checking an OLED. True black on an OLED means the pixels are off, so any that still glow show up right away.
How to check for backlight bleed
- Turn the room lights off and wait a moment for your eyes to adjust.
- Set the screen to a normal brightness, not the maximum. Very high brightness makes every screen look worse than it is in daily use.
- Go full screen on black and look straight at the screen from where you usually sit.
- Bright patches along the edges or in the corners are backlight bleed. A faint, even glow across the whole screen is normal for an LCD.
IPS panels also show "IPS glow": a soft glow in the corners that changes or fades as you move your head. That is a property of the panel type, not a fault. Bleed stays in the same place when you move. If you take a photo to show a seller, use your eyes as the judge: phone cameras exaggerate both.
If you find a problem
Check your monitor's warranty and its pixel policy first; many makers only replace a screen past a certain number of bad pixels, and bleed is judged case by case. A new screen from a store usually has a return window, which is often the easiest way out. Run the dead pixel test for a full check while you are at it.
A monitor arm doesn't change the panel, but it lets you set the screen at the right height and angle, which cuts glare and makes viewing angle issues less visible. The monitor arm finder sorts them by screen size, weight and desk mount.
Questions
How do I make my screen black?
Open this page and press Go full screen. Your whole screen turns black. Move the mouse or tap to see the buttons again, and press Esc to leave.
Does a black screen save power?
On an OLED screen, yes: black pixels are switched off. On an LCD the backlight stays on, so it saves very little. Turning the screen off saves the most.
How do I exit the black screen?
Press Esc on a keyboard. On a phone or tablet, tap the screen and press Exit full screen.
Is some backlight bleed normal?
A little is common on LCD monitors, especially on large or cheaper panels. What counts is whether you notice it in normal use, not in a pitch dark room at full brightness.
Is there a white screen too?
Yes. Pick White here, or open the white screen page.