yGuard

Free Java™ Bytecode Obfuscator and Shrinker

Name Obfuscation

yGuard protects your .class files from reverse engineering by replacing package, class, method, and field names with inexpressive characters. If afterwards the obfuscated .class files are decompiled, it will be extremely difficult to derive the original purpose of the obfuscated code entities.

Code Shrinking

yGuard drastically reduces the size of the input Jar files if your application does not use all of the contained bytecode. This reduces the startup time of your application.

The shrinking engine analyzes the bytecode of all input Jar files in order to determine which code entities can not be reached from a set of given code entry points. These obsolete code fragments (either entire classes or single methods and fields) will then be removed by yGuard. If you use any third party libraries, you will probably benefit a lot from the yGuard shrinking engine, since applications usually do not use all of the functionality provided by an external library and a large fraction of the contained bytecode and resources can be safely removed.