flutter-reducing-app-size

Measure and optimize Flutter app bundle size across platforms with analysis tools and reduction strategies.

- Generates detailed size analysis JSON files via --analyze-size flag to identify large packages, libraries, and assets contributing to bloat

- Visualize and compare builds using DevTools app size tool with treemap inspection and diff functionality to track optimization progress

- Supports Android (APK/AAB), iOS, and desktop platforms with platform-specific workflows, including iOS app thinning size estimation via Xcode

- Implements four core reduction strategies: debug symbol splitting, unused resource removal, library resource minimization, and media compression

Reducing Flutter App Size

Contents

- Core Concepts

- Workflow: Generating Size Analysis Files

- Workflow: Analyzing Size Data in DevTools

- Workflow: Estimating iOS Download Size

- Workflow: Implementing Size Reduction Strategies

- Examples

Core Concepts

- Debug vs. Release: Never use debug builds to measure app size. Debug builds include VM overhead and lack Ahead-Of-Time (AOT) compilation and tree-shaking.

- Upload vs. Download Size: The size of an upload package (APK, AAB, IPA) does not represent the end-user download size. App stores filter redundant native library architectures and asset densities based on the target device.

- AOT Tree-Shaking: The Dart AOT compiler automatically removes unused or unreachable code in profile and release modes.

- Size Analysis JSON: The --analyze-size flag generates a *-code-size-analysis_*.json file detailing the byte size of packages, libraries, classes, and functions.

Workflow: Generating Size Analysis Files

Use this workflow to generate the raw data required for size analysis.