As we inch closer to the stable Android 12 release, Google is making some foundational changes to app delivery and distribution on Android devices. From August 2021, all the new apps on the Play Store will be published in the Android App Bundles (.aab) format instead of the existing APK format. So what are the major differences between an APK and Android App Bundles (AAB)? Can we sideload AABs just like APKs? To answer all your questions, we have come up with this detailed guide on APK vs AAB. So without wasting any time, let’s dive right in.
Here, we have explained both AAB and APK formats in layman terms so that anyone can understand the concept with ease. We have also detailed how to install AAB files, extract APKs from AABs, and more. You can expand the table below to move to any relevant section quickly.
- APK vs AAB: Understanding the Basics
- The Sharing of Private Signing Key with Google
- Is AAB Going to Make Things Harder for Third-party App Stores?
- Can We Sideload AABs Just Like APKs?
- APK vs AAB: Advantages and Disadvantages
APK vs AAB: Understanding the Basics
First, we need to grasp some basics to properly understand what are the differences between an APK and an Android App Bundle.
In an ideal situation, a developer has to build and upload multiple APKs on the Play Store based on the user’s region, processor type, and screen density. When a user taps on the “Install” button in the Play Store, the correct and most-suited APK is then installed on their device. However, all of this puts an enormous task in the developer’s hands. They not just have to develop apps but also manage multiple APKs to support a boatload of devices.
So what really changes here? Starting August 2021, developers don’t have to handle and manage a whole bunch of APKs for a wide array of devices. With AAB, developers hand over everything to Google – the app code, assets, heavy resources, all language packs, and most importantly, the private app signing key. Now, Google can generate and serve optimized APKs to users based on their device’s configuration. It can create a much smaller AAB bundle, one that’s compact in size, installs in a jiffy, and eats lesser data for low-end devices. That’s the main proposition of AAB vs APK, but there is more to unpack.
Looking at what AAB brings to the table, it seems like a great alternative to APK. The AAB format reduces the app size, and developers don’t have to build multiple APKs. However, many developers have expressed concern regarding the sharing of private signing key with Google.
Is AAB Going to Make Things Harder for Third-party App Stores?
From what we know, it seems like sideloading AABs on Android devices will be possible, but it will not be as convenient as sideloading APKs. Android’s package installer currently does not support AAB packaging format, meaning on-device AAB installation won’t be possible natively. However, you can use third-party installer apps to install an AAB package on-device.
After going through all the points, you can tell that AABs won’t make much difference in terms of user experience for most users. Yes, it will reduce the app size, which will be helpful for most users. For instance – Airbnb reduced its app size by 22% after switching from APK to AAB, whereas Netflix toned down its app size by 57%. That is a considerable difference in app size. Apart from that, the abandoned Instant app feature will get a new lease of life with AAB on Android devices.
As for developers most affected by this change, they don’t need to refactor their code, which is great. AABs also bring modularity in tow, meaning they can change a code snippet and merge it with the core base without facing many merging conflicts. One big advantage of AAB is that it brings customization options to developers. They can choose which API level to target or which device type to support. Developers can also decide what all features to deliver on a specific device type or smartphones running on a minimum SDK version.
