How to use the black screen
- Pick a color. Black is selected by default.
- Click Full screen or press F. The color fills your whole display, and the cursor and buttons hide after a moment.
- Press Space or the arrow keys to cycle colors, and Esc to exit. On a phone or tablet, tap the screen to show the Next color and Exit full screen buttons.
While the color is full screen, the page asks the browser to keep the display awake, so it won't dim or lock after a minute. That works in current Chrome, Edge, Safari and Firefox; battery saver modes can still override it.
To send a color to someone, press Share result. The link holds only the color’s code (for example #ffffff for white); whoever opens it sees the color and its code, and can use it here with Use this color. Full screen never starts on its own.
What each color is good for
- Black: check backlight bleed and IPS glow in a dark room, confirm OLED pixels switch off, or dim a secondary monitor.
- White: spot dust, smudges and dead (black) pixels, or use the screen as a soft light for calls and tracing.
- Red, green, blue: reveal stuck sub-pixels that stay lit or dark in one channel. For a guided check, use the dead pixel test.
- Gray and custom colors: a mid gray shows uneven brightness (clouding or banding) better than black or white, and a custom color lets you match a background or a test pattern.
How to check for backlight bleed and IPS glow
- Wait until the room is dark, or at least dim, and set the monitor to the brightness you normally use. Maximum brightness exaggerates bleed you would never notice.
- Open the black screen in full screen and look at the panel straight on from your usual seating distance.
- Backlight bleed is light leaking around the edges or corners of an LCD. It stays in the same place when you move your head.
- IPS glow is a silvery or orange sheen, usually in the corners, that changes or fades as you move your head. It is normal for IPS panels and is not a defect.
Phone cameras make both look far worse than they are, so judge with your eyes, not a long-exposure photo. Some bleed is common on LCD monitors; patches you can see in normal dark scenes in films or games are worth raising with the seller while you can still return the screen. OLED screens have no backlight, so a black screen on OLED should look completely dark.
Cleaning your screen
Dust and fingerprints stand out best on a black screen with a lamp shining across it, while smudges show well on white. Turn the display off (or let it cool) before you wipe it, use a soft microfiber cloth, and dampen the cloth lightly with water if needed. Never spray liquid directly onto the screen, and avoid window cleaners, ammonia and paper towels, which can damage anti-glare coatings. On a touchscreen, tapping while the color is full screen only shows the buttons, so wiping doesn't close it.
Troubleshooting
- Full screen doesn't work on iPhone: Safari on iPhone doesn't let web pages go full screen, so the color fills the whole browser window instead. Tap the color and press Exit full screen to return.
- The screen still dims or locks: Low Power Mode or battery saver can overrule the page. Plug in, or raise your auto-lock time while you use it.
- Black doesn't look fully black: on LCD monitors the backlight always shines through a little. Night light, blue light filters or HDR settings can also tint whites and grays.
Testing a new monitor? Check its real refresh rate with the refresh rate test. Using a white screen as a light for video calls? See the result in the webcam test.