OLED and AMOLED Wallpapers: Battery, Black Levels and Burn-In

Why OLED treats black differently

An LCD has a backlight that shines through every pixel, and the panel blocks light to make dark areas. Even a black image therefore has the backlight running behind it. An OLED or AMOLED screen has no backlight: each pixel produces its own light, and a pixel showing pure black is simply switched off. That is where OLED's deep blacks and very high contrast come from, and it is why dark wallpapers look so different on these screens.

Most flagship phones, many laptops and a growing number of desktop monitors use OLED panels. Your device's specifications will say which kind of display it has.

Do dark wallpapers save battery?

On an OLED screen, yes, but the effect is smaller than it is often claimed to be. Power use depends on how many pixels are lit and how bright they are, so a mostly black wallpaper draws less power than a bright one while it is visible. The wallpaper is usually only partly visible behind apps, though, and screen brightness matters far more than the picture. The saving is largest at high brightness and with a dark system theme, and modest in everyday use.

On an LCD there is no meaningful saving, because the backlight runs at the same level whatever the image.

True black and near-black

Wallpapers made for OLED usually use true black, a pixel value of exactly 0, 0, 0, for the background. That is what switches pixels off. A background that only looks black, such as a very dark grey or a JPEG with slight noise in the shadows, keeps those pixels faintly lit. The difference is easy to see in a dark room: true black merges with the bezel, while near-black glows slightly.

Compression can spoil this. Heavily compressed JPEG files often turn smooth black areas into faint blocks of almost-black. Download the original file rather than a re-saved copy, and prefer PNG for wallpapers that are mostly flat black. Some OLED panels also show a slight smear when pixels switch on from fully off during fast scrolling; a background of near-black instead of true black can reduce it, at the cost of a small amount of contrast.

Burn-in and how to avoid it

OLED pixels age with use, and pixels that show the same bright content for a very long time can age faster than their neighbours. The result, called burn-in or image retention, is a faint permanent ghost of that content. The usual culprits are not wallpapers but fixed interface elements: status bars, navigation bars, taskbars and on-screen logos.

• Dark wallpapers help. Dimmer pixels age more slowly than bright ones.
• Change the wallpaper now and then. Rotating images spreads wear more evenly.
• Hide fixed elements on desktop OLED monitors. Auto-hiding the taskbar or dock and using a short screen-off timer reduce static content.
• Keep the panel's care features on. Many OLED monitors run a pixel refresh routine in standby; let it finish rather than unplugging the screen.

Modern panels are much more resistant than early ones, and normal use with varied content rarely causes visible burn-in.

Choosing a wallpaper for an OLED screen

Images with a black background and a bright, colourful subject make the most of OLED: think auroras, space, neon and minimal designs. Browse the OLED / AMOLED and Dark / AMOLED categories for wallpapers chosen with this in mind. As with any wallpaper, pick a resolution at least as large as your screen, as explained in the resolution guide.