What is an APK file? Android packages explained

The short answer

An APK (Android Package) is a zip archive with a fixed layout that Android knows how to install. It holds the app's compiled code, its resources (images, layouts, translations), a manifest that declares the app's name, version, permissions and minimum Android version, and the developer's signature. When you tap Install, Android verifies the signature, checks the manifest against your device and copies the contents into place.

Google Play installs apps the same way. The difference is that Play downloads the package for you in the background and, for most modern apps, splits it into several smaller APKs tailored to your device. A file you download yourself is usually a single "universal" APK that works on any device, or an XAPK bundle that packs the splits together.

What is inside

The signature matters more than anything else. Android refuses to update an installed app with a package signed by a different key, which is why a file from the developer's own build always installs over the Play version but a re-signed "mod" never does.

Version name and version code

Every APK carries two version fields. The version name is the text people see, such as 12.10.1. The version code is an integer that only ever increases, and it is what Android compares when deciding whether a package is newer. Two builds can share a version name and differ in version code, which is why the version pages on this site list both.

When you would download an APK yourself

• Your device runs an Android version the current release no longer supports, and an older build still works.
• An update removed a feature or broke something, and you want to go back.
• The app is not offered in your country's Play Store.
• You use a device without Google services.

In all of these cases the package you install is the same build the developer published; nothing on this site is repackaged. See how to install APK and XAPK files for the installation steps and how to downgrade an app for the rollback procedure.

Safety

Download from established sources, check that the package name matches the app you expect, and compare the signature with the installed copy when in doubt. Android's Play Protect scans sideloaded packages as well, and a mismatch between the file and the developer's known signature is the clearest warning sign. The guide on verifying an APK before installing walks through the checks.