An APK file is an app created for Android, Google's mobile operating system. Some apps come pre-installed on Android devices, while other apps can be downloaded from Google Play. Apps downloaded from Google Play are automatically installed on your device, while those downloaded from other sources must be installed manually.

APK file open in Windows Explorer after extraction Typically, users never see APK files because Android handles app installation in the background via Google Play or another app distribution platform. However, there are many websites that offer direct APK file download for Android users who want to install apps manually themselves. In this case, you should be careful that you trust the source of the APK file, because malware can be distributed in APK files, just as it can in the case of Windows and .EXE files. How do I install an APK file on my Android device? You can install APK files manually by following these instructions. Make sure that you trust the source of the APK file. What does an APK file contain? Android packages contain all the necessary files for a single Android program. Below is a list of the most prominent files and folders: META-INF/: Contains the manifest file, signature, and a list of resources in the archive lib/: Native libraries that run on specific device architectures (armeabi-v7a, x86, etc.) res/: Resources, such as images, that were not compiled into resources.arsc assets/: Raw resource files that developers bundle with the app AndroidManifest.xml: Describes the name, version, and contents of the APK file classes.dex: The compiled Java classes to be run on the device (.DEX file) resources.arsc: The compiled resources, such as strings, used by the app (.ARSC file) How do I view the contents of an APK file? APK files are saved in a compressed .ZIP format and can be opened by any Zip decompression tool. Therefore, if you would like to explore the contents of an APK file, you can rename the file extension to ".zip" and open the file, or you can open the file directly through a Zip application's open dialog box. How do I create APK files? Android apps are developed using Android Studio, the official IDE for Android software developers. It is available for Windows, Mac, and Linux, and it allows users to develop apps and prepare them for upload to a distribution service, such as Google Play. When apps are ready, developers can build them into APK files and sign them for release. NOTE: See the .AAB description for details on Google's new publishing format for developers.