ProGuard

ProGuard is a tool for shrinking, optimizing, obfuscating, and stripping unused code in Java and Android applications. It helps reduce APK/AAB size, protect source code from reverse engineering, and improve performance.

🔹 Key Features of ProGuard

1. Shrinking: Removes unused classes, methods, and fields.

2. Optimization: Optimizes bytecode for better performance and reduced size.

3. Obfuscation: Renames classes, methods, and variables to meaningless short names, making it harder to reverse-engineer.

4. Stripping: Removes unnecessary libraries and code to minimize the application size.

🔹 ProGuard in Android

• Built into the Android SDK but has been largely replaced by R8 since Android Studio 3.4 (R8 is faster and more efficient).

• Activated in release mode by enabling minifyEnabled in build.gradle:

  gradleCopyEditbuildTypes {
      release {
          minifyEnabled true
          proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
      }
  }

🔹 Things to Watch Out for

• May accidentally remove necessary code (especially with reflection, Gson, Retrofit).

• Requires a proguard-rules.pro file to keep essential components, for example:

  proguardCopyEdit-keep class com.example.model.** { *; }
  -keep class com.google.gson.** { *; }