How to decompile a JAR file with Vineflower from command line?

Download the latest vineflower.jar from GitHub releases and run 'java -jar vineflower.jar ', with arguments detailed on the website for customization.

Vineflower or Fernflower: which is better for Java 17 decompilation?

Vineflower is a modern fork with better support for Java 17+ features and multithreading, while Fernflower is older but stable; for up-to-date needs, Vineflower is preferred.

Can Vineflower handle Kotlin bytecode effectively?

Yes, as a general-purpose JVM decompiler, it can decompile Kotlin, but output may not fully capture Kotlin-specific idioms like extension functions without additional tuning.

How to integrate Vineflower into a Gradle build script?

Add 'implementation org.vineflower:vineflower: ' to dependencies, then use the provided API to call decompilation methods programmatically in your tasks.

Is it legal to use Vineflower on proprietary software?

Decompilation legality varies by jurisdiction and software licenses; Vineflower is a tool, but users must ensure compliance with terms like fair use or license agreements.

Does Vineflower work well with obfuscated code like ProGuard outputs?

Vineflower focuses on quality for standard bytecode; for heavily obfuscated code, it may produce less readable output, and pre-deobfuscation tools might be needed.

Open-Awesome

Vineflower

Apache-2.0Java1.12.0

A modern Java and JVM language decompiler focused on high-quality, clean, and accurate code output.

Visit Website GitHub

2.3k stars144 forks0 contributors

What is Vineflower?

Vineflower is a modern decompiler for Java and JVM languages that converts compiled bytecode back into human-readable source code. It focuses on producing highly accurate and cleanly formatted output, supporting the latest Java features up to Java 21+. The project is a fork of the Fernflower decompiler, continuing its development with an emphasis on quality and usability.

Target Audience

Java developers, reverse engineers, and security researchers who need to analyze or recover source code from compiled JARs, class files, or other bytecode artifacts.

Value Proposition

Developers choose Vineflower for its superior output quality, support for modern Java features, and faster multithreaded decompilation compared to other decompilers. Its accuracy and clean code generation make it ideal for serious code analysis and debugging tasks.

Overview

Modern Java decompiler aiming to be as accurate as possible, with an emphasis on output quality. Fork of the Fernflower decompiler.

Use Cases

Best For

Decompiling modern Java applications using records and sealed classes
Reverse engineering JAR files to recover lost source code
Analyzing third-party libraries for security vulnerabilities
Integrating decompilation into custom build tools or IDEs
Comparing decompiler output quality for academic or research purposes
Debugging obfuscated or minified Java bytecode

Not Ideal For

Developers needing decompilation for non-JVM languages like .NET or native code
Teams requiring a drag-and-drop GUI tool without command-line interaction
Projects involving heavily obfuscated bytecode without prior deobfuscation steps
Environments where Java 11 or higher is not available or feasible to install

Pros & Cons

Pros

Modern Java Support

Decompiles Java 21+ features like records, sealed classes, and pattern matching, ensuring compatibility with latest language updates as listed in the README.

Clean Output Formatting

Generates well-formatted, readable source code with automatic formatting, making decompiled code easier to analyze and debug.

Multithreaded Performance

Uses multiple threads for faster decompilation of large codebases, improving efficiency for reverse engineering tasks.

Flexible Integration

Can be run from command line, integrated as a library in build tools like Gradle, or used via an IntelliJ IDEA plugin, offering versatile usage options.

Cons

Java Version Dependency

Requires Java 11 or higher (version 1.9+) or Java 17 (version 1.11+), which may force environment updates and limit compatibility with older systems.

Limited IDE Support

Only has an official plugin for IntelliJ IDEA, leaving users of Eclipse or other IDEs without built-in integration and requiring manual setup.

Command-Line Complexity

Using from command line involves downloading JARs and managing arguments, which can be intimidating for non-technical users or quick tasks.

Frequently Asked Questions

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