What is this?
Shield4J is a Java class and Android APK obfuscator, encrypter, shrinker and merger based on a powerful, easy-to-use and cheap online service and command line tool.
How does it work?
Shield4J is implemented under a multilayer protection schema, transparent to the user and provided as a service through a user-friendly interface on this site and as a easy-to-use command line tool.
Shield4J is fully-compatible with all versions of Java 2 to date (from JDK/JRE 1.2 up to and including the latest 1.7) and Android APK (latest Dalvik VM).
Shield4J's obfuscation makes your code stronger against reverse-engineering and reduces the JVM and Dalvik VM class loading time and memory consumption.
Test the Shield4J service for free by clicking here or pressing the green button below. This will open a new window with the protection console.
Now you can download and use the new Shield4J's command line tool for integrating the protection into any automatic build process (like Ant).
If the performance of your application is very important, perhaps you should consider not using any of the Shield4J encryption features.
Future lines of work
The next Shield4J versions will come with profiles for supporting Java in Blackberry, J2ME and JSP protection.
Frequently asked questions
Shield4J's obfuscation makes your code stronger against reverse-engineering and reduces the JVM class loading time and memory consumption.