Which Android version introduced notification channels?

Android 8.0 Oreo introduced notification channels. Released on August 21, 2017, Oreo changed notifications from a mostly app-wide stream into organized categories that users could manage individually.

With notification channels, an app can separate alerts into types—for example, direct messages, promotions, downloads, or background activity. Users can then control each channel's importance, sound, vibration, visibility, and whether it appears on the lock screen. This gave people more precise control without requiring an app to disable all notifications at once.

The feature is sometimes confused with notification grouping or notification dots. Oreo supported those related improvements too, but channels were a distinct system for categorizing notifications. Android 8.0 also introduced picture-in-picture support, background-execution limits, Autofill, and Project Treble. Developers targeting Android 8.0 or higher must create channels for notifications, while older apps can be assigned compatibility behavior by the system.