ReDex: An Android Bytecode Optimizer

ReDex is an Android bytecode (dex) optimizer originally developed at Facebook. It provides a framework for reading, writing, and analyzing .dex files, and a set of optimization passes that use this framework to improve the bytecode. An APK optimized by ReDex should be smaller and faster than its source.

Quick Start Guide

Dependencies

ReDex depends on folly, glog, double-conversion, boost and zlib, and uses autoconf/automake for building. Getting these dependences is easiest using a package manager.

Mac OS X:

brew install autoconf automake libtool python3
brew install boost double-conversion gflags glog libevent

Ubuntu 14.04 LTS:

sudo apt-get install \
    g++ \
    automake \
    autoconf \
    autoconf-archive \
    libtool \
    libboost-all-dev \
    libevent-dev \
    libdouble-conversion-dev \
    libgoogle-glog-dev \
    libgflags-dev \
    liblz4-dev \
    liblzma-dev \
    libsnappy-dev \
    make \
    zlib1g-dev \
    binutils-dev \
    libjemalloc-dev \
    libssl-dev \
    libiberty-dev

Download, Build and Install

ReDex includes folly as a git submodule. Initialize it using:

git submodule update --init

Now, build ReDex using autoconf and make.

autoreconf -ivf && ./configure && make && make install

Usage

To use ReDex, first build your app and find the APK for it. Then run:

redex path/to/your.apk -o path/to/output.apk

With any luck, the result output.apk should be smaller and faster than the input. Enjoy!

More Information

The blog Optimizing Android bytecode with ReDex provides an overview of the Redex project.

License

ReDex is BSD-licensed. We also provide an additional patent grant.