OLED Black Screen Test: True Black, Burn-In and Uniformity

This page opens on pure black and has nine more test colors lined up in the order an OLED check needs them: near-black, mid gray, then the solid colors. Press Full screen, and Space or → moves to the next one. Do it in a dark room, and walk up close for the grays.

1. Pure black: are the pixels really off?

Each OLED pixel makes its own light; there is no backlight behind the panel. At #000000 every pixel is off, so a working OLED should look exactly like a screen that is powered down: no glow in the corners, no lighter band along an edge. A single bright dot on black is a stuck or hot pixel rather than burn-in, and the dead pixel test finds and maps those.

2. 5% gray: the panel’s own flaws

At #0d0d0d every pixel has to give a tiny and equal amount of light, which is where OLED panels are least even. Look for thin vertical or horizontal lines, cloudy blotches, or a strip that is darker than the rest. RTINGS photographs a near-black gray like this in its TV reviews, because it exposes problems that show in dark scenes. Newer panels usually do better: its 2018 LG B8 showed vertical bands at 5% gray, its 2024 LG B4 almost none.

3. 50% gray and the solid colors: burn-in

Burn-in is a faint, lasting copy of something that stayed on the screen for a very long time. It is easiest to see on a flat, even field, so step slowly through #808080 and the six solid colors and look for a shape. Check where static things sit on your device:

• Phones: the status bar, the navigation bar or gesture handle, the keyboard.
• TVs: channel logos and news tickers. After months of CNN on RTINGS’s long-term test, the Breaking News banner at the bottom became noticeable with real content on every OLED TV in it.
• Monitors, laptops and handhelds: the taskbar or dock, a docked window, a game’s health bar or map.

Don’t stop at gray. In RTINGS’s 20/7 burn-in test the red sub-pixel wore fastest, so a mark can be plain on red and faint on gray. White comes last, for patches with a different tint from the rest of the screen.

Retention fades, burn-in stays

If you find a mark, watch something varied for a while and run the colors again. Apple’s note on its OLED iPhones separates the two: image persistence disappears after a few minutes of normal use, while burn-in can occur when the same high-contrast image is shown at high brightness for prolonged periods.

What the makers’ refresh cycles do

• LG OLED TVs run Pixel Refresher on their own when you switch the TV off after more than 4 hours of viewing in total, and a longer pass of about an hour after 2,000 hours, during which lines may appear. You can also start it from the OLED panel settings; the menu path depends on the model year.
• Samsung OLED monitors run a screen optimization when they switch off after 4 or more hours of use. Models that have it offer a manual Pixel Refresh under Settings, All Settings, General & Privacy, Panel Care; the monitor turns off for over an hour while it works.
• iPhones with OLED screens record how much each pixel is used and adjust the display to reduce visible burn-in, according to Apple, which also recommends auto-brightness and Auto-Lock.

If a mark survives the refresh cycle, look at the warranty before you pay for a repair: whether burn-in is covered differs between brands and countries.

Back to the plain black screen for other colors. The same tool also runs as a tracing light box and a video call light.

The 10 colors on this page