APK Size Optimization Guide for React Native Apps

Reducing your React Native APK size is essential for improving install rates, conserving user data, and boosting app performance — especially in bandwidth-sensitive markets. This guide outlines proven techniques to shrink your APK size by up to 50–70%, using battle-tested React Native optimizations.

🎯 Optimizations Applied

1. 🔧 Build Configuration Improvements

• ✅ Split APKs by ABI
  Generates architecture-specific APKs for:

  • armeabi-v7a (older devices)

  • arm64-v8a (modern devices)
    ➤ Results in 30–40% size savings per APK.

• ✅ ProGuard & R8 Enabled
  Minifies, optimizes, and obfuscates Java/Kotlin bytecode to remove dead code and shrink classes.

• ✅ Resource Shrinking
  Automatically removes unused drawables, layouts, and strings during the build process.

• ✅ ZIP Alignment
  Aligns uncompressed data within the APK to improve loading speed and performance.

• ✅ PNG Optimization
  Crunches and compresses PNG assets automatically for leaner binaries.

• ✅ Hermes Engine
  Replaces JavaScriptCore with Hermes for faster startup and smaller bundle size.

2. 🎨 Asset & Resource Optimization

• ✅ Removed Unused Densities
  Excluded unused drawable densities like mdpi, hdpi, xhdpi, and xxxhdpi, keeping only xxhdpi.

• ✅ Limited resConfigs to English
  Stripped out unused languages to keep only en.

• ✅ Image Optimization
  Reduced image assets from ~200KB to ~86KB using WebP and manual compression.

3. ⚙️ JavaScript & Bundling

• ✅ Hermes JavaScript Engine
  Smaller JS engine with better GC and faster cold start times.

• ✅ RAM Bundles (Optional)
  Enables lazy loading of JS modules, ideal for large apps.

Size Reduction Summary

Building Optimized APKs

# Clean build artifacts
cd android && ./gradlew clean && cd ..

# Assemble the release builds
cd android && ./gradlew assembleRelease

Find the APKs at:

android/app/build/outputs/apk/release/
├── app-arm64-v8a-release.apk
└── app-armeabi-v7a-release.apk

Installation Instructions

• Modern Devices (2017+) → Install app-arm64-v8a-release.apk

• Older Devices → Install app-armeabi-v7a-release.apk

• Not Sure? → Try arm64-v8a first, then fallback to armeabi-v7a if needed