The Android App Bundle (AAB) is replacing the APK as the file you upload to Google Play. Since August 2021, new apps must be published as an AAB, and Google Play then builds the APKs each phone installs. The APK itself isn’t going away: it’s still the format Android installs, and you still use it for testing and sideloading.
Why AAB replacing APK on Google Play happened
Google made the AAB the required upload format for new apps because it lets Google Play send each device only what it needs. In its June 2021 announcement, Google said it would start requiring new apps to use the Android App Bundle from August 2021, and that this would “replace the APK as the standard publishing format.”
The reason given was size. According to that post, apps built from bundles are on average 15% smaller than a universal APK. Google also noted that over 1 million apps were already using app bundles in production at the time.
The format wasn’t new in 2021. The Android App Bundle FAQ says it launched in 2018. The 2021 change only made it mandatory for new Play apps.
How an Android App Bundle works
An app bundle holds all of your app’s compiled code and resources, but it isn’t an installable app. Google’s guide to app bundles describes it as a publishing format that “defers APK generation and signing to Google Play.”
After you upload one:
- You upload the
.aabfile to Play Console. - Google Play splits it into optimized APKs for each device configuration (screen density, CPU type, language).
- A phone downloads only the code and resources it needs.
- Google Play signs those APKs with your app signing key.
That last step is why Play App Signing comes with the bundle. Play Console’s help page on releases and bundles says that to use app bundles, you must enroll in Play App Signing. Google holds the key that signs what users install. For what that signature protects, see signed vs unsigned APK and our explainer on APK signature schemes v1, v2 and v3.
Who has to use AAB, and since when
The AAB requirement covers new apps first, then grew to a few more cases. Here’s the timeline from Google’s current pages:
| Date | What changed | Source |
|---|---|---|
| 2018 | Android App Bundle launched | AAB FAQ |
| August 2021 | New apps on Google Play must use AAB | Android Developers Blog |
| June 30, 2023 | TV app updates can’t use APKs any more | Play Console Help |
| Current | Private apps on managed Google Play from Play Console must use AAB | AAB FAQ |
In June 2021, Google said existing apps were exempt and that updates to them had “no change.” The current FAQ also mentions a key upgrade option for apps created before August 2021.
The private-apps rule is a good example of why 2021 articles are now out of date. The 2021 post said private apps for managed Google Play were exempt. The current FAQ says they’re required to publish AABs, with APK publishing still supported through the Managed Play iframe.
APK files are still everywhere
The APK is still Android’s install format, so it isn’t being retired. The AAB FAQ is direct about this: app bundles “cannot be installed on Android devices,” and they must be processed by a distributor into APKs.
You’ll keep using APKs for:
- Testing on your own phone. You install an APK directly.
- Sideloading. The FAQ says AABs do not prevent users from installing APKs from any source.
- Other app stores and your own website. Play Console lets you download a signed universal APK, signed with your Play App Signing key, and distribute it elsewhere.
- Sharing builds with testers. Google’s bundletool has a
--mode=universaloption that builds one APK with every resource. It’s bigger, but easier to hand to testers.
One real snag with split APKs: the app bundle guide warns that sideloaded installs missing a required split APK fail on Android 10 and higher. If you share files outside Play, share a universal APK, not one split. A failed install of that kind often shows up as the error covered in why your APK says “App not installed”.
Which file to use for which job
The simplest rule: AAB goes to Google Play, APK goes to a device.
| You want to… | Use | Why |
|---|---|---|
| Publish a new app on Google Play | AAB | Required since August 2021 |
| Install and test on your own phone | APK | Phones can’t install an AAB |
| Send a build to a friend or client | Universal APK | One file, works on any supported device |
| List the app on another store or your site | Universal APK | AABs need a distributor to turn them into APKs |
| Ship a large game | AAB with Play Asset Delivery | Bundles don’t support .obb expansion files |
On size: Google’s guide says new apps larger than 200 MB use Play Feature Delivery or Play Asset Delivery, and the compressed APKs needed to install an app must total no more than 4 GB.
What this means if you build a WebView app
If you turn a website or HTML into an app, the AAB rule changes your upload, not how you test. You still install an APK on a phone first, then send the AAB to Play Console.
The free APK vs AAB guide explains how webtoapkfree.com handles this: it gives you a signed APK for installing and testing on a device, and an AAB for a separate store submission such as Google Play. Signing runs in your browser, and the signing key isn’t uploaded to a build server. Generated apps need Android 8.0 or newer.
The limitation to know: a generated AAB is not Google Play approval. You still need a developer account, a store listing, testing and policy compliance. For the testing part, read about Google Play’s testers rule.
My take: test the APK on a real phone before you ever touch Play Console. A broken login or blank screen is far cheaper to find on your own device than in a review. And back up the encrypted signing key outside browser storage, because the builder keeps it only in that one browser.
FAQ
Can I still upload an APK to Google Play?
Not for a new app. New apps have had to use the Android App Bundle since August 2021, and TV apps need it for updates too since June 30, 2023. Some older apps created before the rule were exempt for updates.
Will my phone stop installing APK files?
No. Google’s own FAQ says app bundles cannot be installed on devices. Google Play turns the bundle into APKs, and Android still installs APKs from Play, other stores and websites.
Can I get an APK from my AAB for other stores?
Yes. Play Console lets you download a signed universal APK for other stores and websites, and bundletool can build a universal APK locally.
Do I need Play App Signing to use an AAB?
Yes. Google requires Play App Signing for app bundles, because Google Play signs the APKs it generates from your bundle.
Sources
- The future of Android App Bundles is here (Android Developers Blog)
- About Android App Bundles (Android Developers)
- Android App Bundle frequently asked questions (Android Developers)
- Inspect app versions on the Latest releases and bundles page (Play Console Help)
- bundletool (Android Developers)
- Create and set up your app (Play Console Help)