Side by side
| APK | AAB | |
|---|---|---|
| Full name | Android Package (Kit) | Android App Bundle |
| Installs on a phone | Yes, directly | No — not installable by itself |
| Google Play (new apps) | Not accepted | Required since August 2021 |
| Share by link, email, QR | Yes | No |
| Other stores | Widely accepted | Varies by store |
| Signed by | You (or your builder) | You with an upload key; Google re-signs for delivery |
What an APK is for
An APK is a ZIP-format package with your app's code, resources, manifest and signature. Android installs it directly. Use APKs for testing on your own phone, sending a build to a client, distributing from your website, or sharing in a classroom — see sharing an APK without the Play Store.
What an AAB is for
An AAB contains everything needed to build APKs, split by screen density, CPU architecture and language. Google Play's servers generate and sign a tailored APK for each device ("Play App Signing"), so users download less. You cannot install an AAB on a phone by tapping it.
Which one do you need?
- Only installing or sharing the app yourself → APK (free).
- Publishing on Google Play → AAB (Pro), signed with a key you keep for every update — see app signing explained.
- Both → build the AAB for Play and an APK for testing and direct sharing.
Can you convert APK to AAB?
Not reliably by renaming or repackaging. Build the AAB from the same project instead. With APK Maker, Pro builds output AAB directly from the same app settings.
What's inside each file
| APK contains | AAB contains |
|---|---|
AndroidManifest.xml (binary)classes.dex (compiled code)resources.arsc, res/assets/ (your bundled website)lib/ (native libraries)Signature ( META-INF/ and/or signing block) |
base/ module with manifest, dex, res, assets and lib folders split by typeOptional feature modules BundleConfig.pb (how to split)Bundle metadata Upload-key signature |
How an AAB reaches users
- You build an AAB and sign it with your upload key.
- Google Play verifies the upload key and stores the bundle.
- For each device, Play generates split APKs (base + density + CPU + language).
- Play signs them with the app signing key and delivers only what that device needs.
This is why a 20 MB AAB can install as a 9 MB download on one phone, and why App Links and sign-in services must know the Play app signing key — see app signing explained.
Testing an AAB yourself
Upload it to Play Console's internal testing track and install from the tester link — the fastest way. Developers can also generate APKs locally from an AAB with Google's bundletool.
Make your APK now — free
No Android Studio, no code, no watermark. Pick what you are starting from:
Frequently asked questions
Can I upload an APK to Google Play?
Not for new apps. Since August 2021 Google Play requires new apps to be published as an Android App Bundle (AAB).
Can I install an AAB file on my phone?
Not directly. An AAB is a publishing format; Google Play generates installable APKs from it.
Is an AAB smaller than an APK?
The AAB file can be larger, but the APKs Google Play generates from it are usually smaller for each user, because each device gets only what it needs.