ToolsFebruary 9, 20261 min readby 0xt0pus

JD-GUI

Java decompiler GUI for viewing decompiled Java source from JAR and class files

#android#mobile-pentesting#reverse-engineering

jd-gui

Description

A standalone graphical Java decompiler that displays the Java source code of .class files contained in JAR files. It is commonly used in Android reverse engineering to view decompiled code from JAR files produced by dex2jar.

Usage 1: Open a JAR File for Code Review

Open the jd-gui application and drag the .jar file into it to browse through the decompiled Java source code.

Command:

Open jd-gui.exe software and drag the .jar file there

Usage 2: Save All Decompiled Sources

Export all decompiled Java source files so you can work with them outside of jd-gui.

Steps:

File > Save All Sources

Notes

  • The tool is also referred to as JD-JUI in some references.
  • It is used to decompile the JAR file and allows you to browse through the source code.
  • String values may not be correctly reconstructed during decompilation, so values such as deedbeef etc. may appear.
  • Alternative decompilers that serve a similar purpose include procyon and Fernflower.