SIZE-REDUCTION-TIPS.md

Size Reduction Tips [Android]

• Following the below steps will help you to reduce the app size by over 60%.

1. First compress your asset files (png, jpg, gif), use any online free image compressor website to compress it.
2. Enable hermes engine
3. Update you proguard rules -> android/app/proguard-rules.pro:

• Apply react-native: https://github.com/facebook/react-native/blob/main/ReactAndroid/proguard-rules.pro
• Apply hermes: https://reactnative.dev/docs/hermes
• Apply Zoom SDK:

-keep class  us.zoom.**{*;}
-keep class  com.zipow.**{*;}
-keep class  us.zipow.**{*;}
-keep class  org.webrtc.**{*;}
-keep class  us.google.protobuf.**{*;}
-keep class  com.google.crypto.tink.**{*;}
-keep class  androidx.security.crypto.**{*;}

• Make sure to also apply proguard rules for react-native-* libs that you use, e.g. for react-native-svg -> -keep public class com.horcrux.svg.** {*;}

4. Open AndroidManifest.xml and add inside application tag the following:

<application
 ...
 android:extractNativeLibs="true"
 ...
>
 ...
</application>

5. Go to android/app/build.gradle and enable:

def enableSeparateBuildPerCPUArchitecture = true
def enableProguardInReleaseBuilds = true

Proguard shrinks, optimizes and obfuscates Java code. It is able to optimize bytecode as well as detect and remove unused instructions.

Now add the lines wherever I've mentioned //ADD THIS LINE:

android {
    ...

    defaultConfig {
        applicationId "com.zoom"
        minSdkVersion rootProject.ext.minSdkVersion
        targetSdkVersion rootProject.ext.targetSdkVersion
        versionCode 18
        resConfigs "en" //ADD THIS LINE 
        versionName "1.1.7"
        multiDexEnabled true
    }

    ...

    buildTypes {
        debug {
            signingConfig signingConfigs.debug
        }
        release {
            // Caution! In production, you need to generate your own keystore file.
            // see https://reactnative.dev/docs/signed-apk-android.
            shrinkResources true //ADD THIS LINE
            signingConfig signingConfigs.debug
            signingConfig signingConfigs.release
            minifyEnabled enableProguardInReleaseBuilds
            proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
        }
    }
    ...
}

Fix Android App crash after bundle release to Play Store

If you're running /gradlew bundleRelease to release your app on Playstore then you need to disable progaurd

def enableProguardInReleaseBuilds = false

& rest of the above settings will remain the same & once progaurd is disabled then rebuild the app and upload the bundle file to playstore again which will fix the crash.

Google Play uses your app bundle to generate and serve optimized APKs for each device configuration, so only the code and resources that are needed for a specific device are downloaded to run your app. You no longer have to build, sign, and manage multiple APKs to optimize support for different devices, and users get smaller, more-optimized downloads.

See diff for the example app: mieszko4/react-native-zoom-us-test#33

Size Reduction Tips [iOS]

For iOS follow this: ios-reduce-your-app-size-with-app-thinning

Make sure to set ENABLE_BITCODE = NO; for both Debug and Release because bitcode is not supported by Zoom iOS SDK

References

• zoom-reduce-app-size
• enable extractNativeLibs
• How we reduced our production apk size by 70% in React Native?
• Reduce/Optimize React Native App Size