Introduction: The real deal
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This project aims to deobfuscate most commercially-available obfuscators for Java.

Update 02/20/18

This project will likely be on pause for the next month or two because my arm is broken

Quick Start

  • Download the deobfuscator.
  • If you know what obfuscators were used, skip the next two steps
  • Create detect.yml with the following contents. Replace input.jar with the name of the input
    input: input.jar
    detect: true
  • Run java -jar deobfuscator.jar --config detect.yml to determine the obfuscators used
  • Create config.yml with the following contents. Replace input.jar with the name of the input
    input: input.jar
    output: output.jar
    - [fully-qualified-name-of-transformer]
    - [fully-qualified-name-of-transformer]
    - [fully-qualified-name-of-transformer]
    - ... etc
  • Run java -jar deobfuscator.jar
  • Re-run the detection if the JAR was not fully deobfuscated - it's possible to layer obfuscations

Take a look at for more information.

It didn't work

If you're trying to recover the names of classes or methods, tough luck. That information is typically stripped out and there's no way to recover it.

Otherwise, check out this guide on how to implement your own transformer (also, open a issue/PR so I can add support for it)

Supported Obfuscators

Zelix Klassmaster
SkidSuite2 (dead, some forks are listed here)

List of Transformers

The automagic detection should be able to recommend the transformers you'll need to use. However, it may not be up to date. If you're familiar with Java reverse engineering, feel free to take a look around and use what you need.


I got an error that says "Could not locate a class file"

You need to specify all the JARs that the input file references. You'll almost always need to add rt.jar (which contains all the classes used by the Java Runtime)

I got an error that says "A StackOverflowError occurred during deobfuscation"

Increase your stack size. For example, java -Xss128m -jar deobfuscator.jar

Does this work on Android apps?

Technically, yes, you could use something like dex2jar or enjarify. However, dex -> jar conversion is lossy at best. Try simplify or dex-oracle first. They were written specifically for Android apps.


Java Deobfuscator is licensed under the Apache 2.0 license.

About Me
GitHub: Trinea
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