R8

Spec sheet

What it does

R8 is a Java program shrinking and minification tool that converts Java bytecode to optimized DEX code; the same repository includes D8, which converts Java bytecode to DEX.Read 4 Oct 2026 · r8.googlesource.com

Product

The repository contains D8, which converts Java bytecode to DEX, and R8, which shrinks and minifies Java programs while producing optimized DEX code.Read 11 Oct 2026 · r8.googlesource.com

Intended users

The documentation describes R8 as an app optimizer and recommends enabling it for a tested release build, while warning that optimization can increase build time and make debugging harder.Read 4 Oct 2026 · developer.android.com

Support

The project directs users to [email protected] for questions and to separate issue trackers for D8 and R8.Read 11 Oct 2026 · r8.googlesource.com

Android integration

The Android Gradle plugin ships with R8 embedded, and the repository documents how to override that version.Read 11 Oct 2026 · r8.googlesource.com

Build

The documented source build uses Chromium depot_tools and produces a JAR containing both R8 and D8.Read 11 Oct 2026 · r8.googlesource.com

Build requirements

Building from source requires depot_tools and a Java 8 compiler and runtime; the documented IntelliJ setup points to a Linux JDK path.Read 4 Oct 2026 · r8.googlesource.com

Compatibility limit

R8 is not command-line compatible with ProGuard; keep rules must be passed in a configuration file using --pg-conf.Read 11 Oct 2026 · r8.googlesource.com

Configuration

R8 uses the ProGuard configuration format to configure whole-program optimization and application entry points.Read 11 Oct 2026 · r8.googlesource.com

Contributions

Contributors must sign a Contributor License Agreement, or a Corporate Contributor License Agreement when the contribution belongs to their employer.Read 11 Oct 2026 · r8.googlesource.com

D8 modes

D8 defaults to debug mode, and its release mode removes debugging information to produce smaller DEX files.Read 11 Oct 2026 · r8.googlesource.com

Distribution

Stable and development builds are available from Google Maven, and the project also documents CI archive downloads.Read 4 Oct 2026 · r8.googlesource.com

Downloads

Stable and development prebuilt versions are available from Google Maven and the project's CI archive.Read 11 Oct 2026 · r8.googlesource.com

Input and output

R8 consumes class files and can output DEX for Android apps or class files for Java apps.Read 11 Oct 2026 · r8.googlesource.com

Integration

Android Gradle Plugin ships with R8 embedded, and users can override the embedded version with a prebuilt or locally built JAR.Read 4 Oct 2026 · r8.googlesource.com

Notable limitation

The R8 command line is not compatible with ProGuard in every respect; for example, keep rules must be supplied in a file rather than on the command line.Read 4 Oct 2026 · r8.googlesource.com

Obfuscation

R8 shortens class, field, and method names to reduce DEX file size.Read 4 Oct 2026 · developer.android.com

Optimization

R8 removes unreachable code and can optimize execution through method inlining and class merging.Read 4 Oct 2026 · developer.android.com

Other build systems

R8 can be integrated into a Bazel build pipeline, though the Android Developers page says Bazel is not officially supported for Android app development.Read 4 Oct 2026 · developer.android.com

Platform requirements

The build instructions say the first run bootstraps Gradle and required JDKs, and Android-targeted R8 use requires an Android SDK platform android.jar.Read 11 Oct 2026 · r8.googlesource.com

R8 compiler

R8 is a whole-program optimizing compiler focused on reducing program size.Read 11 Oct 2026 · r8.googlesource.com

Resource optimization

R8 optimizes resources as part of its optimization phases with Android Gradle Plugin 8.12.0 and later.Read 4 Oct 2026 · developer.android.com

Security and compliance

The opened R8 project page contains no security or compliance claims.Read 4 Oct 2026 · r8.googlesource.com

Plans and prices

Every R8 plan and price →

Where Specifiction places it

• Code Obfuscation Software#11 of 348.0