How I Reduced My React Native 0.81 APK Size by 50% (Without Breaking Anything)

Crafting a lean React Native app is crucial for a smooth user experience, and a hefty APK size can be a real drag. This article shares practical steps to drastically reduce your app's size, specifically targeting React Native 0.81. The author managed to slash their APK size by a whopping 50% without sacrificing functionality, and you can too! A key takeaway is focusing your build on the `arm64-v8a` architecture, as it covers the vast majority of modern Android devices (API level 29+). By setting `enableSeparateBuildPerCPUArchitecture = true` and including only `"arm64-v8a"` in your `build.gradle` file, you can avoid creating a massive universal APK.

Beyond architecture, the article highlights the importance of resource management. Pruning unnecessary languages via `resConfigs` in your `build.gradle` can free up valuable megabytes. Furthermore, enabling resource shrinking (`shrinkResources true`) and PNG compression (`crunchPngs true`) in your release build configuration helps eliminate unused assets. But the real magic lies in optimizing your ProGuard rules. The provided `proguard-rules.pro` file offers a comprehensive, battle-tested configuration for React Native, ensuring that essential code isn't stripped while maximizing obfuscation and size reduction. Don't forget to verify that Hermes, React Native's JavaScript engine, is enabled (`hermesEnabled=true`) for further performance gains.

Remember to always test thoroughly on real devices after implementing these changes. The article stresses the importance of retaining error logs (`Log.e()`) for debugging production issues. By following this craftsman-like approach – focusing on targeted architecture builds, efficient resource management, and robust ProGuard rules – you can significantly reduce your React Native APK size and deliver a faster, more responsive app to your users. Cleaning your builds (`./gradlew clean`) and assembling a release APK (`./gradlew assembleRelease`) will allow you to check the final APK size. Happy coding!

📰 Original article: https://dev.to/ajmal_hasan/how-i-reduced-my-react-native-081-apk-size-by-50-without-breaking-anything-e2a

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