ProGuard is a free Java class file shrinker, optimizer, obfuscator, and preverifier. It detects and removes unused classes, fields, methods, and attributes. It optimizes bytecode and removes unused instructions. It renames the remaining classes, fields, and methods using short meaningless names. The resulting applications and libraries are smaller, faster, and a bit better hardened against reverse engineering.
Reducing the size of Android apps for faster downloads from Google Play, shorter startup times, and smaller memory footprints.
Optimizing code for better performance on mobile devices.
Protecting applications and libraries against reverse-engineering and tampering.
ProGuard’s main advantage compared to other Java obfuscators is probably its compact template-based configuration. A few intuitive command line options or a simple configuration file are usually sufficient. The user manual explains all available options and shows examples of this powerful configuration style.
ProGuard is fast. It only takes seconds to process programs and libraries of several megabytes. The results section presents actual figures for a number of applications.
ProGuard is a command-line tool with an optional graphical user interface. It also comes with plugins for Ant, for Gradle, and for the JME Wireless Toolkit. It is already part of Google’s Android SDK, where it can be enabled with a simple flag.