Wallpaper · Devices with OLED screens
Zero Black
A pure black wallpaper: one 88-byte file.
On OLED screens a black pixel switches off completely and emits no light. Zero Black puts every part of the screen where the wallpaper shows into that state. It is not an app but an image file: no installation, no permissions, no ads.
Available to download
Download
The same file for every device: iPhone, iPad, Android and computers.
Download Zero Black (PNG, 88 bytes)
If you opened this page on your phone, you can press and hold the black square below and save it.
- File
- zero-black.png
- Format
- PNG, 1-bit grayscale
- Size
- 88 bytes
- Resolution
- 256 × 256 pixels
- Color
- Every pixel #000000
- App, permissions, ads
- None
Verification
On a computer, one command shows that the downloaded file is this file:
shasum -a 256 zero-black.png
The expected output starts with f569b175026cfbb77a68f1754f6e1a3c175f3a7a7e930918bd8656240a90e396.
What it saves
What we measured and what we could not measure, kept apart.
Nearly half the screen light
The black wallpaper cut the light the home screen emits by 44% on iPhone, 48% on iPad and 53% on Android.
Less still with dark mode
With dark mode on as well, the cut was 76% on iPhone, 92% on iPad and 80% on Android; 91% on iPhone with dark icons.
Battery depends on brightness
Our estimate: about 1% less power at normal brightness and about 12% at full brightness (the wallpaper alone, while the home screen is showing).
The light figures were measured from simulator and emulator screenshots. The battery figures are not a measurement but a model based on Purdue University's dark-mode measurements on OLED phones (Purdue, 2021). The real saving depends on brightness, use and screen.
Does my device benefit?
The saving exists only on OLED screens. On OLED each pixel makes its own light, and a black pixel switches off. On LCD screens the backlight is always on: Zero Black looks black there too but saves no energy.
The screen type is listed in the device's technical specifications. If it says OLED or AMOLED (also under names such as Super AMOLED or Dynamic AMOLED), it benefits; if it says LCD or IPS, it does not.
How to set it
The paths we tested; names may differ slightly with the device's language and version.
iPhone and iPad
- Open this page in Safari, press and hold the black square and save it to Photos.
- Open the image in Photos, tap Share and choose to use it as wallpaper; add it and set it as a wallpaper pair.
- If you want dark icons, choose them now from the Home Screen's edit menu: a new wallpaper resets the icon style to the default.
Samsung Galaxy
- Download the image and open it in Gallery.
- From the ⋮ menu choose to set it as wallpaper, pick both the lock screen and the home screen, then confirm.
Google Pixel and other Android phones
- Download the image.
- Press and hold an empty spot on the home screen, open the wallpaper and style settings, choose a photo from the wallpapers and apply it.
Mac
- Download the file, right-click it in Finder and set it as the desktop picture.
- Set the scaling to fill the screen.
We have not tried Windows or Linux. The file is a standard PNG, so it can be chosen in the desktop settings; but we make no promises about what we have not tested.
How we tested
Before publishing we set it on a real phone and in emulators, and measured the screens pixel by pixel.
- Samsung Galaxy S25 Ultra (One UI 8.5, real device): set; 76% of the home screen fully off.
- Android 17 emulator, Google's wallpaper app: set.
- iPhone and iPad simulators (iOS 27): set; on iPhone the file saved from Safari to Photos stays unchanged (88 bytes).
- Mac: set as the desktop picture.
- The file itself: every pixel checked one by one; Chrome and macOS decoded it correctly.
Why 88 bytes and not less
A PNG can be as small as 67 bytes (1 × 1 pixel). But Google's wallpaper app crashed on an image that small, and Samsung rejected images under 31 pixels as too small. 256 × 256 is eight times Samsung's limit; the cost is 21 bytes.
Not tested: Windows, Linux, other Android makers, older iOS and Android versions.
Status and contact
Zero Black can be downloaded from this page. If something goes wrong on a device we have not tested, write to us.
For questions about the project: info@bayraktarrobotik.com