d4j - The Free Java Decompiler for Everyone

Let's you look into any Java code even if you don't have the source

New! PRO Edition - The Ultimate Java Decompilation Experience

Export decompiled code, Quickly jump to specific code, View Java bytecode in a separate view.

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Peek Inside

Understand how APIs, components, frameworks, and all the critical code you use really works by decompiling and seeing inside. SecureTeam Java Decompiler let's you look into any Java code even if you don't have the source, making it fully visible for you to aid in your debugging efforts, understand how third-party libraries work, and analyze your optimized code.

Byte Code to Java Code

Decompiles any Java artifact. Support Java 5+ language features like generics and typesafe enums.

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code debugging

Debug your software

Uncover third-party libraries inner workings. Discover the source of hard to find bugs, by seeing where the problem lies - whether it's in your own code, third-party libraries, or components used by your application.

Learn how 3rd-party libraries work

Peek into the third-party libraries or components you're using, find undocumented functionality and get more out of the APIs and technologies you’re using.

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our trusted customers: bnp paribas, assa abloy, parallels, infragistics, verifone, abb, siemens, intel, avepoint