What file extension do Android app packages use?

Android app packages use the .apk file extension. APK stands for Android Package, and an APK is the installable package format used by Android and several Android-based operating systems to distribute apps, games, and middleware.

An APK is essentially a specialized ZIP archive. It can contain compiled program code, resources, images, native libraries, certificates, and the AndroidManifest.xml file, which describes the app's identity, components, permissions, and required features. Android uses this collection to install and run the application.

Developers can build APK files from Android projects written in languages such as Java or Kotlin. Before distribution, packages are digitally signed so Android can identify the publisher and verify updates. Users may install APKs through Google Play or by sideloading them from another source, although security settings and newer Android protections can restrict installations from untrusted locations.

The other options refer to different ecosystems or file types. .ipa is associated with iPhone and iPad applications, .app is used by some Apple platforms and other systems, and .exe is commonly associated with Windows programs. Android App Bundles can be used to generate APKs, but the installed package still uses the .apk suffix.