Google just released the Android 13 beta, one for pixel devices from the Pixel four to the Pixel 6 Pro, and the beta right now only includes 3 new features, but there are now more granular permission controls for shared media files too, so that’s good.
This new beta one also includes all the upgrades from the Android 13 Developer Preview two, including a requirement that apps ask for permission to send notifications, and you’ll also find a new photo picker, Bluetooth LE Audio, and support for MIDI 2.0 instruments over USB.

Anyone can install this beta version on their Pixel devices, although it’s better to not install it on your primary device because Google doesn’t expect to focus on platform stability until June and won’t release the finished Android 13 until sometime nearly after July.
These Android Betas don’t include every user-facing feature. Google didn’t show Android Twelves material. You redesign until Google IO 2021, which was months after the first preview arrived. Although this beta is still useful, it may be worth waiting for Google IO 2022 if you’re interested in great new top-level changes.
