How to Reduce Flutter App Size: Optimization Techniques

Why are Flutter apps larger in size, and how can I optimize their APK size effectively?

// Example command to build a release APK with optimization
flutter build apk --release --target-platform android-arm,android-arm64

Flutter applications are known for their cross-platform capabilities, but they can sometimes result in larger APK sizes compared to native Android applications. This is due to various reasons such as embedded framework binaries, assets, and more. However, several optimization techniques can significantly reduce the size of your Flutter app.

// Command example to build a release APK with optimizations
flutter build apk --release --target-platform android-arm,android-arm64 --split-per-abi

Causes

• Flutter's engine and framework are bundled with every application, which increases the initial size.
• Additional assets like images and fonts can bloat APK size if not optimized.
• Debug mode increases the app size due to additional debugging information.

Solutions

• Use the `--release` flag when building to remove unnecessary assets and debug information.
• Optimize images using formats such as WebP instead of PNG or JPEG.
• Minimize dependencies and avoid including unused packages in your `pubspec.yaml` file.
• Leverage code splitting and lazy loading techniques to reduce the initial app size.
• Remove unused resources and assets by using tools such as ProGuard (for Android) or similar to shrink the final APK.

Mistake: Failing to build using the `--release` flag.

Solution: Always build your final APK for release to ensure unnecessary debug information is excluded and optimizations are applied.

Mistake: Not optimizing images before adding them to the project.

Solution: Use image optimization tools to compress images and convert them to more efficient formats before using them in the app.