[10] DP3 finalized the release's API to API level 26,[10] changed the camera UI, reverted the Wi-Fi and cellular connectivity levels in the status bar back to Wi-Fi being on the left, added themed notifications, added a battery animation in Settings: Battery, a new icon and darker background for the Clock app, and a teardrop icon shape for apps.

On July 24, 2017, a fourth developer preview was released which included the final system behaviors and the latest bug fixes and optimizations.

Its lawn statue was unveiled at a promotional event across from Chelsea Market in New York City—a building which formerly housed a Nabisco factory where Oreo cookies were first produced.

[14] Android 8.1 was released in December 2017 for Pixel and Nexus devices, which features minor bug fixes and user interface changes.

[27] The Android 8.1 update supports the display of battery percentages for connected Bluetooth devices, makes the notification shade slightly translucent, and dims the on-screen navigation keys to reduce the possibility of burn-in.

[15][28] Android Oreo adds support for Neighborhood Aware Networking (NAN) for Wi-Fi based on Wi-Fi Aware,[29] Bluetooth 5,[30] wide color gamuts in apps,[31] an API for autofillers, multiprocess and Google Browsing support for WebViews, an API to allow system-level integration for VoIP apps, and launching activities on remote displays.

This new architecture, called Project Treble,[37] allows the quicker development and deployment of Android updates for devices, as vendors would only need to make the necessary modifications to their bundled software.

[42][43] The Android 8.1 update also introduces a neural network API, which is designed to "[provide] apps with hardware acceleration for on-device machine learning operations."

[46][47] The operating system's interface is also modified, with the quick settings panel providing greater prominence to information regarding the battery, mobile data limit, and available storage, the recent apps menu using a modified layout and being limited to four apps (to reduce RAM consumption), and an API for allowing mobile carriers to implement data tracking and top-ups within the Android settings menu.