Browse free open source Java Decompilers and projects below. Use the toggles on the left to filter open source Java Decompilers by OS, license, language, programming language, and project status.

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  • 1
    JADX

    JADX

    Dex to Java decompiler

    Command-line and GUI tools for producing Java source code from Android Dex and apk files. Decompile Dalvik bytecode to java classes from APK, dex, aar, aab and zip files. Decode AndroidManifest.xml and other resources from resources.arsc. Deobfuscator included. Be aware, Android Studio can interfere with jadx debugger, so it is better to close it before attaching to the process in jadx. Smali debugger, check wiki page for setup and usage. View decompiled code with highlighted syntax.
    Downloads: 1,914 This Week
    Last Update:
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  • 2

    unluac

    A decompiler for Lua 5.x

    unluac is a decompiler for Lua 5.0 through 5.4. It runs on Lua chunks that have been compiled with the standard Lua compiler. It requires that debugging information has not been stripped from the chunk. (By default, the Lua compiler includes this debugging information.) This program is written in Java. A JAR package is available in the downloads section so you don't have to compile it. It runs from the command line and accepts a single argument: the file name of a Lua chunk. The decompiled code is printed to the standard output. Here is an example usage of unluac: java -jar unluac.jar myfile.lua > myfile_decompiled.lua The current version also has pretty good support for Lua 5.0 and Lua 5.1. Support for later versions is also good if the code doesn't use too many gotos.
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    Downloads: 1,064 This Week
    Last Update:
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  • 3
    JD-GUI

    JD-GUI

    A standalone Java Decompiler GUI

    JD-GUI is a standalone graphical Java decompiler that allows users to reconstruct and explore source code from compiled .class files. It provides an intuitive interface for browsing decompiled code, making it easier to inspect methods, fields, and class structures without access to original source files. The tool is widely used for reverse engineering, debugging, and understanding third-party libraries. It supports opening individual files as well as entire archives such as JARs, enabling efficient navigation across large codebases. JD-GUI emphasizes simplicity and accessibility, allowing developers to quickly analyze compiled Java applications. It integrates with standard Java tooling and can be extended with additional modules. Overall, it is a practical utility for developers working with bytecode-level artifacts.
    Downloads: 114 This Week
    Last Update:
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  • 4
    Bytecode Viewer

    Bytecode Viewer

    A reverse engineering suite (decompiler, editor, debugger and more)

    Some of Bytecode Viewer features are that it provides Java Decompiling with Six different decompilers (DJ-GUI/Core, Procyon, CFR, Fernflower, Krakatau, and JADX-Core). Bytecode Decompiling with CFIDE. Android APK integrated with Dex2Jar. Securely launch Java applications and insert hooks via EZ-Injection. Scan for malicious code with the Malicious Code Scanner plugin. Export as DEX, Jar, Class, Zip or Java Source File. Open Android APKs, Android DEX, Java Class Files and Java Jars. (WAR & JSP Support!). Extensively configurable, over 100+ settings! Works seamlessly with all Operating Systems. Integrates BCV into Windows by installing it, it'll associate all .class, .dex and .apk to open with BCV. You can view Jar & APK Resources with ease by APKTool.jar integration. It is 100% free and open sourced under GPL v3 CopyLeft.
    Downloads: 109 This Week
    Last Update:
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  • 5
    FernFlower

    FernFlower

    Decompiler from Java bytecode to Java, used in IntelliJ IDEA

    Fernflower is an open-source Java decompiler originally developed by JetBrains that takes compiled Java bytecode and reconstructs readable source code, helping developers understand, debug, and recover lost Java code from .class files. It works by analyzing the structure of bytecode and inferring higher-level constructs like loops, conditionals, generics, and exception handling to produce Java source that is as close as possible to what a human would have written, making it useful for both reverse engineering and educational purposes. Fernflower is integrated into popular Java IDEs and tools where decompilation is needed, and its robust analysis handles a wide range of language features introduced across multiple Java versions. Because it outputs clean, structured, and often compilable code, developers use it for auditing binaries, exploring third-party libraries without source, and recovering parts of legacy systems where source was lost or unavailable.
    Downloads: 78 This Week
    Last Update:
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  • 6
    Luyten

    Luyten

    An open source Java decompiler Gui for Procyon

    Luyten is an open source Java decompiler GUI for Procyon.
    Downloads: 63 This Week
    Last Update:
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  • 7
    Jad Java decompiler plugin for Eclipse IDE.
    Downloads: 25 This Week
    Last Update:
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  • 8
    The aim of this project is to develope a decompiler for java which is platform independent and has options to obfuscate the class file also. The project takes class file as input and decompiles it and provides the source file.
    Downloads: 23 This Week
    Last Update:
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  • 9
    Jar Explorer is a simple, easy-to-use application to browse the contents of jar files. It also includes a class decompiler.
    Downloads: 15 This Week
    Last Update:
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  • 10
    jd-gui-duo

    jd-gui-duo

    A 2-in-1 JAVA decompiler based on JD-CORE v0 and v1 supporting 3rd par

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    Downloads: 42 This Week
    Last Update:
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  • 11
    HydraDragonAntivirus

    HydraDragonAntivirus

    Open Source Antivirus/XDR for Windows operating system

    Dynamic and static analysis with Real Time Malware Analysis with Antivirus for Windows, including open-source XDR (3 EDR projects), ClamAV, YARA-X, machine learning AI, behavioral analysis, Unpacker, Deobfuscator, Decompiler, website signatures, Ghidra, Suricata, Sigma, Kernel, Hypervisior based protection and much more than you can imagine.
    Downloads: 10 This Week
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  • 12
    JODE is a java package containing a decompiler and an optimizer (aka obfuscator ;-) for java.
    Downloads: 5 This Week
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  • 13
    Swf Reader

    Swf Reader

    Adobe Flash SWF file reader, editor

    Adobe Flash SWF editor which can read and edit bytecode.
    Downloads: 4 This Week
    Last Update:
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  • 14
    ecd

    ecd

    An Eclipse Plugin to integrate different Class Decompiler seamlessly i

    Downloads: 7 This Week
    Last Update:
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  • 15
    jdec is a Java Decompiler. It can be used to reverse the bytecodes present in a .class File to produce a Java Source File which can be nearly correct or equivalent (Due To different Interpretations) to the original java file.[With UI & command line]
    Downloads: 2 This Week
    Last Update:
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  • 16

    JBVD

    Java Bytecode Viewer & Decompiler

    A very powerful java bytecode viewer and decompiler which makes use of the javassist open source library.
    Downloads: 2 This Week
    Last Update:
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  • 17
    Java Decompiler, Disassembler and Bytecode debugger. Decompiler supports Java 5 (e.g. generics, for-each loops etc). Debugger allows user to step through each bytecode and view program state. Contains Swing GUI.
    Downloads: 0 This Week
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  • 18

    DeClassify

    A Java Decompiler with a catchy name.

    A Java Decompiler that is based on the object oriented premise of Java. Everything is an object. The intermediate between bytecode and source os an object.
    Downloads: 0 This Week
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  • 19
    EJDC is a java class file decompiler written by java language. The full name of this project is "Emilio's Java Decompiler".
    Downloads: 0 This Week
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  • 20
    IdeaJad is a free plugin that allows you to decompile java class files from within IntelliJ IDEA using the popular decompiler JAD.
    Downloads: 0 This Week
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  • 21

    JClassViewer

    A Java class viewer and decompiler which respect line numbers.

    JClassViewer is a viewer for class and jar files. Features: - required Java 7 or higher - used the line numbers to reconstruct an output that is near to the original output. - debugging in Eclipse - should support other languages like Scale in the future
    Downloads: 0 This Week
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  • 22
    Java decompilation tools from 'Decompiling Java' book published by Apress.
    Downloads: 0 This Week
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  • 23
    JReversePro is a Java Decompiler / Disassembler written in Java. Facility to view the ConstantPool contents is available. AWT, Swing and command-line versions are present.
    Downloads: 0 This Week
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  • 24
    JadRetro is a Java decompiler helper supporting Java 1.5+ classes. JadRetro is not a decompiler itself, it is a class transformer helping some old (but good) Java decompilers to convert more class files and/or generate more correct source code.
    Downloads: 0 This Week
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  • 25
    Java-program to read, modify and execute class-files. a real java VM written in java or a decompiler for class-files is possible (and partially working)
    Downloads: 0 This Week
    Last Update:
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