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.
Build Agents and Models on One Platform
Everything you need to build production-ready agents and models. Access 200+ Google and third-party AI models and tools.
Gemini Enterprise Agent Platform is Google Cloud's comprehensive platform for developers to build, scale, govern, and optimize agents and models. Choose from Google's most advanced models and third-party models like Anthropic's Claude Model Family.
Start Free
Custom VMs From 1 to 96 vCPUs With 99.95% Uptime
General-purpose, compute-optimized, or GPU/TPU-accelerated. Built to your exact specs.
Live migration and automatic failover keep workloads online through maintenance. One free e2-micro VM every month.
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.
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.
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.
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.
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.
JPEXS Free Flash Decompiler is open-source Flash SWF decompiler
JPEXS Free Flash Decompiler is a free, open-source application for analyzing, editing, and extracting content from Adobe Flash SWF files. It enables users to inspect compiled Flash applications and recover resources such as images, sounds, fonts, shapes, and scripts. The software supports ActionScript 1, 2, and 3 decompilation, allowing developers to examine and modify embedded program logic. Users can replace multimedia assets, edit text, and modify SWF structures without access to the original project files. It also supports converting SWF content into FLA format for further editing. Its integrated interface provides resource previews, script editing, and multiple export options. Built with Java, it runs on Windows, macOS, and Linux and is useful for software preservation, reverse engineering, and Flash content recovery.
PRTG Catches Network Issues Before They Cause Downtime
Threshold-based alerts flag problems early, so your team can act before users notice, not after.
Reactive troubleshooting usually means hearing about a problem from frustrated users, not your monitoring tool. PRTG sets threshold-based alerts across devices, servers and applications, notifying your team by email, SMS or push the moment a metric crosses a set limit. That means catching a failing disk or overloaded server before it becomes an outage and getting time back from firefighting. Start a free trial and set your first alerts today.
Source code of APK Explorer & Editor (AEE), an open-source tool
APK Explorer & Editor is a free, open-source Android application designed for inspecting and modifying APK files. It allows users to browse the contents of installed applications or APK packages stored on their devices. The software can extract resources such as icons, fonts, graphics, and XML files. Its integrated editors support modifying text and binary XML resources. Users can replace or delete resources and reassemble modified Smali code into DEX files. The application also includes tools for decoding resource tables and managing split APKs. Modified applications can be rebuilt and signed for installation. APK Explorer & Editor provides a portable toolkit for Android application inspection, customization, and package management.
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.
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]
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.
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.
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.
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.
You are visitor 01402503 — GeezerVison does not store the pages you look up. Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required.
