Guardsquare / Proguard

Quick Start • Features • Contributing • License

ProGuard is a free shrinker, optimizer, obfuscator, and preverifier for Java bytecode:

• 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. ProGuard is very popular for Android development, but it also works for Java code in general.

❓ Getting Help

If you have usage or general questions please ask them in the Guardsquare Community.
Please use the issue tracker to report actual bugs 🐛, crashes, etc.

🚀 Quick Start

ProGuard is integrated in Google's Android SDK. If you have an Android Gradle project you can enable ProGuard instead of the default R8 compiler:

1. Disable R8 in your gradle.properties:

android.enableR8=false
android.enableR8.libraries=false

2. Override the default version of ProGuard with the most recent one in your main build.gradle:

buildscript {
    //...
    configurations.all {
        resolutionStrategy {
            dependencySubstitution {
                substitute module('net.sf.proguard:proguard-gradle') with module('com.guardsquare:proguard-gradle:7.0.1')
            }
        }
    }
}

3. Enable minification as usual in your build.gradle:

android {
    //...
    buildTypes {
        release {
            minifyEnabled   true
            shrinkResources true
            proguardFile getDefaultProguardFile('proguard-android-optimize.txt')
            proguardFile 'proguard-project.txt'
        }
    }
}

4. Add any necessary configuration to your proguard-project.txt.

You can then build your application as usual:

gradle assembleRelease

The repository contains some sample configurations in the examples directory. Notably, examples/android has a small working Android project.

✨ Features

ProGuard works like an advanced optimizing compiler, removing unused classes, fields, methods, and attributes, shortening identifiers, merging classes, inlining methods, propagating constants, removing unused parameters, etc.

• The optimizations typically reduce the size of an application by anything between 20% and 90%. The reduction mostly depends on the size of external libraries that ProGuard can remove in whole or in part.

• The optimizations may also improve the performance of the application, by up to 20%. For Java virtual machines on servers and desktops, the difference generally isn't noticeable. For the Dalvik virtual machine and ART on Android devices, the difference can be worth it.

• ProGuard can also remove logging code, from applications and their libraries, without needing to change the source code — in fact, without needing the source code at all!

The manual pages (markdown, html) cover the features and usage of ProGuard in detail.

💻 Building ProGuard

Building ProGuard is easy - you'll need:

• a Java 8 JDK installed
• a clone of the ProGuardCORE repository, since ProGuard is built on the ProGuardCORE library

You can then execute a composite build with the following Gradle command:

./gradlew --include-build=../proguard-core assemble

Alternatively, make the composite build persistent by editing this line in gradle.properties. You can also add this line to a gradle.properties file in your Gradle user home (~/.gradle/gradle.properties).

# Optionally set up a composite build with ProGuardCORE.
#proguardCoreDir = ../proguard-core

The artifacts will be generated in the lib directory. You can then execute ProGuard using the scripts in bin, for example:

bin/proguard.sh

You can publish the artifacts (including proguard-core) to your local Maven repository using:

./gradlew --include-build=../proguard-core :proguard-core:publishToMavenLocal publishToMavenLocal

🤝 Contributing

Contributions, issues and feature requests are welcome in both projects. Feel free to check the issues page and the contributing guide if you would like to contribute.

📝 License

Copyright (c) 2002-2020 Guardsquare NV. ProGuard is released under the GNU General Public License, version 2, with exceptions granted to a number of projects.