How to decompile an APK on Android

What does decompiling an APK give you?

Decompiling an APK turns the app's compiled classes*.dex files back into code you can read. Manifesto produces two views of the same class:

View	Engine	Editable	Use it for
Smali	Smali/Baksmali 3.0.9	Yes	Making changes that rebuild cleanly
Java	JADX 1.5.6	No, preview only	Reading and understanding the logic

Smali is a readable form of Dalvik bytecode, so an edit there maps straight back into the DEX file. Decompiled Java is a reconstruction. It is easier to read, but it can't be compiled back into the app reliably, which is why Manifesto keeps it read-only.

How do I decompile an APK on Android?

The steps below use the labels you see in Manifesto's APK editor for Android. Install it first if you haven't: it needs Android 8.0 or newer on an arm64 device.

1. In the file manager, tap the .apk. The APK info sheet opens. Tap Options, or long-press the file instead.
2. Tap Open as project.
3. In the Explorer tab, tap a classes*.dex entry. In the dialog, tick the DEX files you want and tap Decompile. Manifesto disassembles them to Smali.
4. Browse the Smali class tree and tap a class to open it in the editor.
5. Open the editor overflow (Source actions) and tap View as Java.
6. If the class has inner classes, pick them in Java preview parts and tap Preview.
7. Tap View Smali source to switch back to the editable Smali.

Large apps often have several DEX files (classes.dex, classes2.dex and so on). The dialog lets you tick only the ones you need, so you don't have to decompile the rest. The APK projects docs cover the project screen in more detail.

How do I find the code I'm looking for?

Manifesto's Smali editor has search tools so you don't have to read every class:

• Find usages: shows where a class or package is used. Select a symbol in the Smali editor to run it from the toolbar, or long-press a class in the tree.
• Browse symbols: lists the symbols in the open Smali or Java file so you can jump to one.
• Class tree actions: Rename…, Rename package… and Move to package… reorganise classes once you know what they do.

Obfuscated apps use short names like a.b.c, so reading the Java preview next to Find usages is usually the fastest way to work out what a class does. The Smali and Java docs list every editor action.

Can I edit the Java and recompile it?

No. Manifesto can't recompile decompiled Java, because the Java view is a JADX preview with editing switched off. To change behaviour, edit the matching Smali, tap Validate and save, then tap Build and sign. That writes <name>-modified-signed.apk, signed with Manifesto's debug key.

The full loop, from finding the code to installing the rebuilt APK, is in how to edit an APK on Android. To use your own key, see how to sign an APK on Android.

What about split APKs, AAB files and installed apps?

Manifesto decompiles plain .apk files as projects. Other formats need a step first:

• Installed apps: open the drawer, tap Installed Apps, tap the app, then Extract APK. Split apps give Extract APK set, saved as .apks in Manifesto/APKs.
• APKS, XAPK and APKM: these can be viewed and installed, but not rebuilt. Use Convert to APK to merge them into one APK, as in installing XAPK and split APKs.
• AAB: use Convert to APK, which builds a universal APK with bundletool. See converting AAB to APK on Android.
• Native libraries: .so files hold compiled C or C++ code, not DEX. Tap Analyze on a .so file to disassemble it with radare2 and read r2ghidra pseudocode. The native analysis docs explain the views.

Before you start on an unfamiliar APK, the info sheet's Protection row (Analyze APK protection) runs APKiD rules and reports packers or obfuscators it recognises.

Use it responsibly

Only decompile and modify apps you own or are allowed to analyze. Decompiling is for learning, debugging, interoperability and security research, not for removing licence checks or paid features.