JD-GUI-DUO

jd-gui-duo is an unofficial successor to JD-GUI, built on top of Emmanuel Dupuy’s popular Java decompiler and expanded for users who want more than basic Java decompilation. It keeps the familiar foundation of the original tool while turning it into a more capable desktop application for code inspection, comparison, validation, and exploration. For developers, reverse engineers, maintainers, and advanced users working with class files and JAR archives, jd-gui-duo offers a stronger and more versatile continuation of the classic JD-GUI experience.

One of its biggest strengths is its multi-engine design. jd-gui-duo combines JD-Core v0 and JD-Core v1 in the same interface and also supports additional decompilers such as CFR, Procyon, Fernflower, Vineflower, and JADX. This gives users several ways to reconstruct source code from Java bytecode and makes the software especially useful when one engine produces clearer or more complete results than another.

The program also goes beyond simple decompilation. Users can browse archives, open classes quickly, follow hyperlinks inside decompiled code, and move through methods and members with an outline view. Features such as Open Type, advanced class lookup, and built-in search tools make it easier to inspect large libraries and complex applications when original source code is missing.

Another major advantage is its comparison support. jd-gui-duo includes JAR comparison based on a modified JarComp approach and also integrates the NetBeans Visual Diff module for class comparison. That makes it especially useful for checking differences between versions of a library, reviewing upgrades, investigating regressions, and understanding what changed between builds.

The application also uses Eclipse libraries to report compiler errors and warnings in decompiled code and Java source files. This adds practical value because it helps users judge how accurate or complete reconstructed code really is. Eclipse-based parsing and analysis also improve indexing, navigation, and source understanding.

The software supports Maven Central source lookup as well, allowing users to retrieve original published sources when available.

Key features • Dual decompilation with JD-Core v0 and JD-Core v1 • Support for CFR, Procyon, Fernflower, Vineflower, and JADX • JAR comparison for archive-level analysis • Class comparison with the NetBeans Visual Diff module • Compiler errors and warnings powered by Eclipse libraries • Eclipse-based parsing, indexing, and navigation support • Open Type and advanced class lookup • Hyperlink navigation and outline view • Search tools for large codebases • Bytecode inspection and control flow graph viewing • Export of decompiled sources into an archive • Maven Central source lookup