Android 16 has a new trick to speed up app installation

Installing new Android apps or games poses no challenge for most Android devices, but many low-end devices still struggle to install large apps, due to a weak processor or slow storage. In spite of these limitations, Google can still optimize Android to work better on low-end hardware. For example, Google is introducing a new feature in Android 16 that is poised to speed up new app installs, especially on low-end devices.

Specifically, Google has added a new feature called cloud compilation to Android 16. Cloud compilation is a feature that enables application artifacts to be loaded from files downloaded from the Google Play Store, instead of being generated on the device itself. By offloading app compilation to the cloud, Android 16 can speed up the app installation process on low-end devices, especially for apps with a lot of code to compile.

To elaborate, I first need to briefly explain what these “application artifacts” even are. The Android operating system uses the Android Runtime (ART) to execute application code. When a new application is being installed, Android uses a tool called dex2oat to take the APK (Android Package Kit)’s .dex files — which contain the app’s compiled bytecode — and generate one or more application artifacts. In general, these artifacts help the operating system load most applications faster and more efficiently, making them crucial components of the Android OS. Specifically, these artifacts can take several forms: .vdex files, which contain additional metadata to speed up bytecode verification at runtime; .odex files, which contain pre-compiled code for methods in the app; or .art files, which contain ART internal representations of certain strings or classes in the APK to speed up app startup.

The best Android phones can generate these artifacts quickly when installing new apps. Cheap budget phones with weak processors and slow storage chips may take longer to generate these artifacts, especially when dealing with APKs that have many .dex files. Since speedy Internet is so widely available these days, it may be faster to just download precompiled versions of these application artifacts alongside the APK file(s). This is what Android 16’s cloud compilation feature seemingly enables.

Android 16’s cloud compilation feature bypasses the need to run dex2oat during installation. Instead of generating application artifacts on-device, Android 16 pulls them from SDM files that are downloaded from the Google Play Store. SDM is a new file format introduced in Android 16 that contains the cloud compilation artifacts; it stands for Secure Dex Metadata, and they’re signed with the same key used to sign the APK.

Although Android 16 enables cloud compilation, the feature doesn’t seem to be in use yet. This is likely because Google needs to configure the Play Store to generate these application artifacts using dex2oat and then serve them alongside the APK file(s) during installation of apps on Android 16 devices. Setting up this infrastructure and rolling it out will likely be a time-consuming process. It’s possible that Google will make this initially opt-in, especially since it increases the amount of data that users need to download.

We’re excited to see if this feature will noticeably speed up app installs. It’s always interesting to learn about these under-the-hood changes that are invisible to most users and even app developers. If we learn more about this cloud compilation feature in Android 16, we’ll be sure to let you know.