Google is rolling out the final release of Android 8.1 to certain devices.
The operating system will initially be available for Pixel and Nexus devices.
The company also announced the release of Android Oreo Go, which offers a stripped-down version of the operating system for lower-end devices.
Android Go is aimed at devices with 1GB of RAM or less, and includes optimised versions of Google Apps.
Developers can test app compatibility with Android 8.1 using a Pixel or Nexus device, or an emulator.