Let’s dive into it for a bit so you can get a high-level understanding of how the APK is produced. The Android app’s build process is fairly complex. Resources.arsc - file with precompiled resources, such as strings, colors, or styles. dex files (named x, etc.) when the application uses multidex. This contains application metadata - for example, its name, version, permissions, etc.Ĭx - file with app code in the Dex file format. META-INF - directory with APK metadata, such as its signature.ĪndroidManifest.xml - application manifest in the binary XML file format. Contains multiple directories - one for each supported CPU architecture ( ABI). Lib - directory with compiled native libraries used by your app. png files are optimized (crunched) to save space and improve runtime performance when inflating these files. All XML resources are converted to binary XML, and all. These are all resources except the files in res/values. Res - directory with all resources that are not compiled into resources.arsc. APK Package ContentsĪn APK file is a compressed package that contains the following files and directories:Īssets - directory with application assets. It must be digitally signed with a certificate to allow installation on an Android device. An APK file contains app code in the DEX file format, native libraries, resources, assets, etc. APK files are basically ZIP files similar to the JAR files used to package Java libraries.

What Are APK Files?Īndroid applications are distributed as APK files. Its main purpose is showing how to inspect existing Android apps for educational purposes only. Note that the information in this article is not intended for piracy or other illegal uses. Another useful application is learning how a certain app solves some interesting technical issue or works around platform or vendor bugs. One of the most useful applications of these techniques is reverse engineering your own apps to assess how hard it would be to misuse your private code (for example, getting around your license checks). This article presents the basics of Android reverse engineering.

Unzip apk