How to reduce flutter app size and obfuscation ?

Flutter reduce app size  App size is the most important in the term of the apps usage and user retention in an app. Many people are a...

Flutter reduce app size 

App size is the most important in the term of the apps usage and user retention in an app. Many people are asking me about the app size reducing even if they have optimized at their best at coding and asset management. So here is how you can reduce apps size and make it smaller than your normal apk or aab. From the technique in this tutorial you will be able to reduce apk size upto 50%.

Before

Before

After

After

In Production

in Production

Steps to follow:

• Add the following code in your android/app/build.gradle file 

 android/app/build.gradle 

 buildTypes {   
    release {   
    minifyEnabled true   
    shrinkResources true   
    proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'   
    signingConfig signingConfigs.release   
    }   
   }   
  }   

• In the same directory create a file called proguard-rules.pro 

  

  proguard-rules.pro

• If you have firebase implemented in your project then use the following content

 ## 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.** { *; }  
 -keep class com.google.firebase.** { *; }  
 -dontwarn io.flutter.embedding.**  
 -ignorewarnings  

• if you don't have firebase in your project then use the following code

 ## 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.** { *; }  
 -dontwarn io.flutter.embedding.**  
 -ignorewarnings  

• In your gradle.properties file add the following line

 extra-gen-snapshot-options=--obfuscate   

 gradle.properties

• Now you are done build the apk using the following command to see the effect

    flutter build apk --release  

or bundle using

 flutter build appbundle --release

If you build apk you can see about the 20% reduce in size in my case 20mb to 16mb and in the bundle you can see the release apk reduce by 50% , In my case 10mb apk from bundle the app tested in this tutorial can be downloaded from button below:

Download 

If you encounter an error like below 

error

• just remove the text from last step from gradle.properties

 extra-gen-snapshot-options=--obfuscate   

Video Tutorial