How to minify a Flutter app with Proguard?

Question

I already made a Flutter app. The release apk is about 14MB. I searched methods to minify this and found this ons: https://flutter.io/android-release/#enabling-proguard

Answer 1

First, we will enable shrinking and obfuscation in the build file. Find build.gradle file which sits inside /android/app/ folder and add lines in bold

android {

    ...

    buildTypes {

        release {

            signingConfig signingConfigs.debug     

            minifyEnabled true
            useProguard true

            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' 

        }
    }
}

Next we will create a configuration which will preserve entire Flutter wrapper code. Create /android/app/proguard-rules.pro file and insert inside:

#Flutter Wrapper
-keep class io.flutter.app.** { *; }
-keep class io.flutter.plugin.**  { *; }
-keep class io.flutter.util.**  { *; }
-keep class io.flutter.view.**  { *; }
-keep class io.flutter.**  { *; }
-keep class io.flutter.plugins.**  { *; }