What is the difference between an AAB and an APK?

An APK is an app ready to install. An AAB is the developer's master copy for Google Play, holding the code and resources for every device; Play cuts it into APKs for each phone and signs them. The APK viewer opens .apk, .xapk and .apks files; this page opens bundles.

Can I convert an AAB to an APK here?

No, on purpose. The APKs would need signing before Android installs them, and a page that hands out re-signed apps is not one to trust. Developers use bundletool or Android Studio for their own bundles; everyone else should get the app from Google Play or its developer.

How do I see the version code of an .aab?

Open it above: the version code and version name are under the app's name, read from base/manifest/AndroidManifest.xml. The minimum and target API levels are beside them.

Why are the signing fingerprints different from my app on Google Play?

With Play App Signing, which every new app uses, you sign the bundle with your upload key and Google signs the APKs it builds with the app signing key it holds. The certificate here is the upload key; Play Console shows both.

What are dynamic features and asset packs?

Optional modules: a feature module adds code that can be downloaded when needed (a scanner, an editor), and an asset pack carries large files such as game levels or textures. Each module's manifest says when Play delivers it, shown here per module.

Is my bundle uploaded?

No. The file is read by this browser tab on your own device, and nothing is sent anywhere. That matters for an unreleased app.

Stays on your computer How this works

Free AAB viewer: see inside an Android App Bundle

Open an .aab to see the app's package name, version code and name, the Android versions it supports, every permission in plain words, its activities, services, receivers and providers and which of them other apps can start, its feature modules and asset packs, and who signed it. The file is opened in your browser and is not uploaded.

Drop a .aab file here, or click to choose oneIt is opened by your browser, on this computer. Nothing is uploaded.

About the AAB viewer

An Android App Bundle (.aab) is the file developers upload to Google Play since 2021, when it replaced the APK for new apps. Play builds from it the APKs each phone downloads, sized for that phone's processor, screen and language. That makes a bundle awkward to look into: its manifest is not the binary XML of an APK but Protocol Buffers, so APK tools and unzip programs show it as noise, and the usual answer is to install Android Studio or run Google's bundletool on the command line.

This page decodes the bundle's manifests and resource table directly, in the format aapt2 writes them, and lists everything they declare, module by module. It only reads: it does not turn the bundle into an APK, so nothing here can be installed. It is free to use, with no account and no upload limit, and it runs entirely in your browser: nothing is uploaded, and while the page stays open, a feature you have already used keeps working offline.

What you can see

The app's name, icon, package name, version code and version name
The oldest Android version it runs on, the one it targets and the one it was built against
Every permission it asks for, explained in plain words, with the ones Android prompts for marked
Every activity, service, broadcast receiver and content provider, with whether other apps can start it (android:exported) and the permission protecting it
Its modules: the base, dynamic feature modules and Play Asset Delivery packs, and whether each comes at install, fast-follow or on demand
The processors it has native code for, the languages its name is translated into, and the bundletool version that built it
The upload key's certificate, with SHA-1 and SHA-256 fingerprints
What its size is made of, and every file inside as a folder tree, each one saved on its own if you need it

How to check an AAB

Drop the .aab file on the box above, or click the box and choose it.
Check the version code and target API level before uploading: Play refuses a version code it has seen before and a target below its yearly minimum.
Look through the components marked as open to other apps: each one is a way in that you should mean to offer.
Compare the upload key's SHA-1 or SHA-256 fingerprint with the upload key shown on Play Console's app signing page if Play says the bundle is signed with the wrong key.

Why an AAB cannot be installed

A phone installs APKs, never bundles. To try a bundle on a device, developers turn it into APKs themselves with Google's bundletool (build-apks, then install-apks), which signs them with a key of their choosing; Android Studio does the same behind the scenes. This page deliberately does not: an APK made that way needs signing to install, and an app from anyone but its developer or Play is exactly what you should not install. If someone sent you an .aab to "install", ask for the app from Google Play or an APK from its developer instead.

Questions

What is the difference between an AAB and an APK?: An APK is an app ready to install. An AAB is the developer's master copy for Google Play, holding the code and resources for every device; Play cuts it into APKs for each phone and signs them. The APK viewer opens .apk, .xapk and .apks files; this page opens bundles.
Can I convert an AAB to an APK here?: No, on purpose. The APKs would need signing before Android installs them, and a page that hands out re-signed apps is not one to trust. Developers use bundletool or Android Studio for their own bundles; everyone else should get the app from Google Play or its developer.
How do I see the version code of an .aab?: Open it above: the version code and version name are under the app's name, read from base/manifest/AndroidManifest.xml. The minimum and target API levels are beside them.
Why are the signing fingerprints different from my app on Google Play?: With Play App Signing, which every new app uses, you sign the bundle with your upload key and Google signs the APKs it builds with the app signing key it holds. The certificate here is the upload key; Play Console shows both.
What are dynamic features and asset packs?: Optional modules: a feature module adds code that can be downloaded when needed (a scanner, an editor), and an asset pack carries large files such as game levels or textures. Each module's manifest says when Play delivers it, shown here per module.
Is my bundle uploaded?: No. The file is read by this browser tab on your own device, and nothing is sent anywhere. That matters for an unreleased app.