8 Best Java Decompilers in 2020

What is Java Decompiler ?

Java decompiler converts .class file into java source code. In other words, decompiler converts bytecode into readable .java format.You can use java decompiler to look into the code of predefined java classes like HashMap, HashSet , ArrayList etc. You can find out how Sun/Oracle java developers wrote the java classes which are currently used by billion of devices in the world.


Java source code from which the .class file has been generated will not exactly match the java source code generated from the java decompiler. But most of the code will be same.


Read Also :  Java 8 Features

After installing java, you can find the predefined java classes in the rt.jar inside JRE folder. Unzip rt.jar and all the predefined java classes will be present in the bytecode(.class) format. By using java decompiler, I have written the articles how HashMap works in java, how HashSet works in java. So let's find out best java decompilers which I have used and now I am recommending it to you. 

Best Java Decompilers



1. JDProject

JDProject is one of the most frequently used java decompiler offline.It is developed to decompile java 5 or later versions(as of now till java8). It is available for Windows, Mac OS and Linux. It is a best decompiler for eclipse and intellij too as it provides plugin for each platform. JD-Eclipse is a plug-in for the Eclipse platform while JD-Intellij is a plug-in for Intellij IDEA.
You can download JDProject java decompiler from here

JDProject Java Decompiler




2. Procyon 

Procyon is a java decompiler developed by Mike Strobel. Procyon decompiler handles java language enhancements from jdk 1.5 and beyond that most other decompilers don't. Procyon does well with enum declarations, annotations and java 8 lambdas and method references. You can find the wiki here comparing Original code, Procyon decompiler code and JD decompiler code. Although wiki above makes Procyon looks good, but I still prefer JDProject over Procyon. Procyon is relatively new and still work in progress.



3. Cavaj Java Decompiler  

If you are a Windows user, then Cavaj is a good option as a decompiler. It is simple to use and decompiles nearly any java class file. The main drawback of Cavaj is that it lacks syntax highlighting.
Also, it is not available for Mac or Linux OS. In short, it is a freeware standalone windows application which converts bytecode(.class) files to java source code.

cavaj java decompiler


4. DJ Java Decompiler

DJ Java Decompiler is yet another standalone windows application. It is available for Windows XP, Windows 2003, Windows Vista, Windows 7, Windows 8, 8.1 and 10. You don't need to have the JVM (Java Virtual Machine) or any other java JDK installed. The main advantage of DJ Java Decompiler is that you can decompile more than one java class file at one time. DJ Decompiler enables users to users to save, print, edit and compile the generated java code.

5. JBVD

JBVD stands for java bytecode viewer and decompiler. It is based on the javassist open source library. It is only available for Windows OS. JBVD requires java to be installed on your device to work.

6. AndroChef

AndroChef is also a windows based java decompiler application. With AndroChef Java Decompiler you can decompile apk., dex, jar and java class-files. It's simple and easy. AndroidChef supports  Windows XP, Windows 2003, Windows Vista, Windows 7, Windows 8, 8.1 and 10. AndroChef successfully decompiles java6, java 7 and java 8 .jar and .class files.

best java decompilers


CFR stands for Class File Reader. It is completely written in java 6. It supports latest features of java8 like lambdas while decompiling. You do not need to worry if you are using java 8. The only drawback of this decompiler is that it is not an open source program. Although, it has a command line tool which is ideal in making the decompiling process efficient and faster.

8. Fernflower

Fernflower is an analytical decompiler for java. It is used to decompile class, zip and jar file extensions. It is still under development.

Conclusion

There are many options available for java decompiler. If you have MacOS ,Linux OS or looking for eclipse,intellij plugin then go for JDProject. For Windows OS there are many options available like DJ decompiler, JBVD, AndroChef, Cavaj, JDProject. Please mention in the comments if you come across any java decompiler which is not mention in the above list. Thats all, I have shared the 8 best java decompilers for java developers.

About The Author

Subham Mittal has worked in Oracle for 3 years .
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