everything you need to know about AAB

Google is working with developers to introduce Android App Bundles in the Play Store. AAB, more powerful than APK, promises faster, smaller, and easier app updates. But how does it work and what does it mean for the future of Android?

Android application package

The announcement hit the bomb in early summer 2021: Google no longer wants the APK format for the Play Store and is working to replace it with the AAB (Android App Bundles) format. But why this decision? What are the differences between APK and AAB? What are the advantages of AAB over APK? What will this change for the future of Android? So many questions we are trying to answer in this magazine.

What is an APK?

APK stands for Android Package Kit. This is the historical file format used on Android. APK compiles all the files necessary for the proper operation and installation of the application in a compressed way. All Play Store apps are in APK format, and you can download any APK file from outside the official app store to install the app on your Android terminal.

When will AAB become mandatory in the Play Store?

From August 2021, all new applications submitted to the Play Store must be submitted in AAB format. The measure therefore currently only applies to new services. After all, we can imagine Google forcing developers to move from APK to AAB once the update is implemented to standardize the app’s trading experience.

Leave APK?

Switching to AAB format in the Play Store is far from synonymous End of APK. First, because AAB is actually a way to deliver APKs more efficiently to user terminals. If a publisher no longer publishes an APK in the Play Store for the benefit of the AAB, at the end of the day it will still be the APK contained in the AAB that corresponds to running the application on the device.

In addition, as noted earlier, existing apps may continue to use APK instead of Play Store AAB. However, most vendors of the most popular applications voluntarily switch to AAB and take advantage of its benefits.

Why is Google replacing APK with AAB?

First, it is clear that AABs are not new. This format already existed, but it existed with the APK. If we talk about it much more after it became the recommended format for the Play Store and mandatory for new apps, the technology is well known and some publishers have even adopted this standard before Google’s recent guidelines. We’ll see in detail a little later how AAB is a more powerful form of Play Store APK in terms of both security and performance.

But let’s pause for a moment on a topic that Google hasn’t yet raised. With AAB, Mountain View can better manage the app ecosystem and put its Play Store even more at the center of the Android experience to the detriment of third-party app stores. These provide APKs for apps, and if publishers choose to publish their apps in AAB format only, they will lose the richness of their list. Note that Google has provided the tool to developers Convert to AAB APK, but there is no guarantee that these will play the game and make the APKs available once they have been upgraded to AAB, exclusively in the Play Store. The Android package installer does not support AAB, so installing the app through AAB without an official app store is not possible (initially).

Windows 11 Android application
Credit: Microsoft

Google can also indirectly put sticks on Microsoft’s wheels. Windows 11 originally supports Android apps that can be downloaded and installed on your computer from the Microsoft Store, which is based on the Amazon Appstore, which, like other alternative app stores, needs APKs.

What is the Android App Bundle?

Android App Bundle on Mail format for Google Play which compiles all the code and resources compiled by the application. This code and these resources are then processed dynamically create and deliver customized and optimized APK for each device. Therefore, developers no longer need to create, sign, and manage multiple APKs to optimize support for different devices. All information is collected in one place and intelligently distributed to users as needed. So users get a lighter version of the app as it is optimized specifically for their device.

The goal is to improve the application installation experience while reducing uninstallation speed (each application takes up less space). All without increasing the workload for developers who should quickly get their mark on this system and who have there is no need to change the application code switch to AAB, at least if it has been developed in accordance with Google’s recommendations.

Android application package
Credit: Google

What is the difference between AAB and APK?

When you download an APK from the Play Store, you get all the app files, including the ones you don’t need. With AAB, all files are available in the Play Store, but only useful elements are installed on the terminal. The device only shares files due to the screen configuration, architecture, and default language. With AAB application downloads and installations are faster, less bandwidth is used and applications are less heavy and take up a lot of space less storage space.

Credit: Google

Google provides examples of popular apps that have been streamlined using the Android App Bundle. Dropbox is 33% lighter, Duolingo 42%, Airbnb 22%, Twitter 13%, Netflix 57%, Tinder 28% and LinkedIn 36%.

The download time of the application is shortened not only due to the reduced size of the APK created by AAB, but also due to additional features. In particular a supplementary system which you can download as needed, you can add features and content that are not necessary later, after the first installation, either during the use of the application or when the user wants to use that function or content. Thus, large features that are not needed for installation, features for a specific audience, and rarely used features can be included in a dynamic feature pack.

Android application package
Credit: Google

For developers, the Android App Bundle is also a way to deploy updates much more efficiently, sometimes without having to force a user to visit the Play Store to update their apps. The modules still pass the security check Google Play Protect, this does not cause additional security and reliability issues for applications and updates.

Until now, we had Quick applications, a preview that allows you to launch the service without even installing it to explore and test. But compatible applications are still quite rare and require developer effort. With AAB, it is possible to launch an application that has not yet been 100% downloaded because its essential components are readily available. A system we know well with PC or console games that lands on Android. Convenient when the connection is slow or in heavy games.

Android application package
Credit: Google

Finally, The Android App Bundle promises smaller, more powerful, faster and easier to update apps.

Delivery of Play resources, delivery of Play features, what is it?

Two concepts go hand in hand with AAB: Play Asset Delivery and Play Feature Delivery, which make the Android App Bundle what it is and contribute greatly to its benefits with a simple APK. Play Asset Delivery and Play Feature Delivery replace OBB (Opaque binary blob) extension files that are not supported by AAB.

Play feature delivery refers to the previously described dynamic modular system. It allows you to customize which feature modules are shared on which device and when. According to Google, 10% of the most popular apps already use Play Feature Delivery.

Play Asset Delivery reduce the time it takes to download and install games by prioritizing the handling of key issues. Other information, such as textures and sounds, will not be processed until later. In addition, the compression tool only supplies the device with resources that are compatible with the user’s device, so it is not full of items that it cannot use. Publisher servers are less involved and the user experience becomes smoother.

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