Black Wallpaper

What it makes

A PNG image in which every pixel is #000000 — pure black, not a dark gray — at the size you choose. Common phone and monitor sizes are one press away, This screen fills in the size your browser reports for the screen you are using, and you can type any size from 16 × 16 to 7680 × 4320. It starts on a common phone size, because that is where a black wallpaper is most often wanted.

Does it save battery?

It depends on the kind of screen, and on how much of the wallpaper you actually see.

• On an OLED screen, each pixel makes its own light, and a pixel showing pure black makes none. So a black wallpaper can reduce the power the screen uses. By how much depends on the phone, the brightness, and how much of the screen shows the wallpaper rather than icons, widgets and apps.
• On an LCD screen, a backlight shines behind every pixel whatever the image, so a black wallpaper saves little or nothing.

This page gives no percentage or battery-life figure, because the saving depends on things it cannot know. Whether a screen is OLED or LCD is in the device's specifications; a web page cannot detect it. And if saving power on an OLED screen is the goal, the dark mode in your device's settings usually covers far more of the screen than the wallpaper does.

Made on your device, and checked

The image is drawn by your browser and saved straight from it: nothing is uploaded, and ScreenTail keeps no copy. Before it is saved, the page reads it back to confirm its size and samples it to confirm it is pure black; if your browser cannot make the size you asked for, the page says so instead of handing you a broken file. Setting it as your wallpaper is done in your device's own settings.

For a black screen to use right now rather than a file, there is the Black Screen; for keeping an OLED screen healthy, the OLED burn-in guide.