Google is setting Android App Bundles (AAB) as the standard publishing format starting August 2021. Sideloading enthusiasts won’t have to worry as Android Packages (APKs) aren’t going away, they’re just being absorbed into the app bundles. Developers of existing and private apps won’t need to bother with the format as this new publishing requirement only applies to new apps on the Play Store.
Google, on a page dedicated to the Android App Bundle, talks about how smaller app downloads can benefit users. However, it has one minor disadvantage: The Android App Bundles format, launched in 2018 at I/O, is only used by Google Play, which could potentially increase the complexity of app redistribution.
With the app bundle, Google Play generates and serves optimised APKs that takes into account configurations and languages on a device, thus helping to reduce the app size by making sure only the code and resources that are needed for a specific device are downloaded. AAB-distributed applications are typically 15% smaller than universal APKs on average due to this optimisation. End users will see faster installation and increased storage space.
App bundles are used by over one million applications, says Google. Most of the top 1,000 applications and games on the Play Store are included in this set. These apps and games include Twitter, Netflix, Gameloft titles, Adobe, and Duolingo.
In addition to the AAB requirements, developers will have to replace large expansion files (OBBs) with Play Asset or Feature Delivery. Similarly, Instant-enabled Android App Bundles replace the Instant app ZIP for distributing new and updating “instant experiences.”