APK decompilers | HackTricks (2024)

For further details on each tool check the original post from https://eiken.dev/blog/2021/02/how-to-break-your-jar-in-2021-decompilation-guide-for-jars-and-apks/#cfr

JD-Gui

As the pioneering GUI Java decompiler, JD-Gui allows you to investigate Java code within APK files. It's straightforward to use; after obtaining the APK, simply open it with JD-Gui to inspect the code.

Jadx

See Also

Reverse engineering in AndroidReverse Engineering an apk using Jadx-GuiHow can you prevent reverse engineering of mobile applications?A Quick Guide to Reverse Engineering Malware 

Jadx offers a user-friendly interface for decompiling Java code from Android applications. It's recommended for its ease of use across different platforms.

• To launch the GUI, navigate to the bin directory and execute: jadx-gui

• For command-line usage, decompile an APK with: jadx app.apk

• To specify an output directory or adjust decompilation options: jadx app.apk -d <path to output dir> --no-res --no-src --no-imports

GDA-android-reversing-Tool

GDA, a Windows-only tool, offers extensive features for reverse engineering Android apps. Install and run GDA on your Windows system, then load the APK file for analysis.

Bytecode-Viewer

With Bytecode-Viewer, you can analyze APK files using multiple decompilers. After downloading, run Bytecode-Viewer, load your APK, and select the decompilers you wish to use for simultaneous analysis.

Enjarify

Enjarify translates Dalvik bytecode to Java bytecode, enabling Java analysis tools to analyze Android applications more effectively.

• To use Enjarify, run: enjarify app.apk This generates the Java bytecode equivalent of the provided APK.

CFR

CFR is capable of decompiling modern Java features. Use it as follows:

• For standard decompilation: java -jar ./cfr.jar "app.jar" --outputdir "output_directory"

• For large JAR files, adjust the JVM memory allocation: java -Xmx4G -jar ./cfr.jar "app.jar" --outputdir "output_directory"

Fernflower

Fernflower, an analytical decompiler, requires building from source. After building:

• Decompile a JAR file: java -jar ./fernflower.jar "app.jar" "output_directory" Then, extract the .java files from the generated JAR using unzip.

Krakatau

Krakatau offers detailed control over decompilation, especially for handling external libraries.

• Use Krakatau by specifying the standard library path and the JAR file to decompile: ./Krakatau/decompile.py -out "output_directory" -skip -nauto -path "./jrt-extractor/rt.jar" "app.jar"

procyon

For straightforward decompilation with procyon:

• Decompile a JAR file to a specified directory: procyon -jar "app.jar" -o "output_directory"