Building a 1MB Flutter App: Myth or Reality?

This article was translated specially for the channel FlutterPulseYou'll find lots of interesting things related to Flutter on this channel. Don't hesitate to subscribe!🚀

Why 1MB remains unrealistic for mobile apps — and the proven techniques that actually work to minimize Flutter app sizes.

The Hard Truth: 1MB Flutter Apps Don't Exist (And Here's Why)

Every developer dreams of shipping ultra-lightweight apps, but let's address the elephant in the room: a 1MB Flutter mobile app is fundamentally impossible.

Use this linkto read this blog for free — and support my work!

Here's what you're actually working with:

• Flutter engine baseline: ~3.2MB compressed (C++ runtime + Skia graphics + Dart VM)
• Minimal "Hello World" APK: 4.7MB (as confirmed by Flutter's official documentation)
• Real-world production apps: 15-50MB after adding features, assets, and third-party packages

The engine isn't bloat—it's what makes Flutter's cross-platform magic possible. Remove it, and you no longer have Flutter.

What "Small" Actually Looks Like in 2025

Based on current Flutter documentation and community benchmarks:

Android (APK/AAB)

• Absolute minimum: 4.7MB (empty app with --split-per-abi)
• Typical production app: 15-30MB
• Well-optimized production app: 8-15MB

iOS (IPA)

• Baseline: Generally 20-30% larger than Android due to App Store encryption and different compilation targets
• Download size vs install size: App Store Connect shows the actual download size users experience

The New Reality: Google Play's 16KB Page Size Requirement

Beginning November 1st, 2025, all new apps and updates to existing apps submitted to Google Play and aiming at devices with Android 15+ must be built to support 16 KB page sizes. This affects how you should structure your build process but doesn't change baseline app sizes.

Proven Size Optimization Strategies (2025 Edition)

1. Use Android App Bundles (AAB) Instead of APKs

Google Play Console now prioritizes AAB format, which automatically optimizes delivery:

flutter build appbundle --release

Why this matters: App Bundles optimize the delivery process by splitting the app into various modules and dynamically delivering only what's needed for each device

2. Enable Comprehensive Shrinking in build.gradle

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

Impact: R8 compiler with tree shaking can reduce APK size by 30-40%

3. Leverage Flutter's Built-in Tree Shaking

Flutter's build process includes tree shaking, which removes unused code from the release build, but you need to compile in release mode:

flutter build apk --release --split-per-abi --obfuscate --split-debug-info=/path/to/symbols

4. Asset Optimization (Often the Biggest Win)

Run the size analysis first:

flutter build appbundle --analyze-size

Then optimize based on findings:

• Convert PNG → WebP (up to 80% size reduction)
• Remove unused font variations
• Compress Lottie animations
• Use vector graphics where possible
• Implement lazy loading for large assets

5. Strategic Package Management

Audit your dependencies:

flutter pub deps --style=compact

Common size culprits in 2025:

• Firebase SDK: 2-5MB (use only needed services)
• Google Maps: 3-8MB (consider alternatives like MapBox)
• Camera plugins: 1-3MB
• Heavy UI libraries: Some add significant overhead

Real-World Case Studies

Production E-Commerce App

• Size reduction: 68MB → 27MB (60% smaller)
• Optimizations:
• Migrated to Android App Bundle
• Enabled R8 with aggressive optimization
• Converted product images to WebP
• Removed 15 unused dependencies
• Compressed Lottie animations by 70%
• Business impact: 23% increase in download completion rates

Social Media Platform

• Size reduction: 45MB → 18MB (60% smaller)
• Key findings:
• 70% of app size = unused image assets + redundant fonts
• Multiple font weights bundled, but only 2 used
• Background images stored in multiple resolutions
• Optimizations:
• Removed 12MB of unused resources
• Implemented dynamic font loading
• Switched to vector graphics for UI elements

Complete Flutter App Size Optimization Checklist

1. Pre-Optimization

• Run flutter build appbundle --analyze-size
• Use Flutter DevTools App Size Tool

2. Build Config

• Enable R8 shrinking + resource shrinking
• Use --obfuscate --split-debug-info
• Always publish with App Bundle or --split-per-abi

3. Assets & Resources

• Convert PNG/JPEG → WebP (50–80% smaller)
• Remove unused font weights
• Compress/reduce animations
• Prefer scalable formats (SVG) instead of heavy raster images

4. Code & Dependencies

• Remove unused packages
• Replace heavy packages with lighter alternatives
• Verify tree shaking works in release builds
• Strip out debug code & logging

5. Post-Optimization Verification

• Check Google Play Console size reports
• Review App Store Connect install sizes
• Compare across device configs
• Track download completion improvements

When Flutter Isn't the Right Choice

Flutter is incredible for productivity and cross-platform consistency, but not ideal when extreme small size is the #1 constraint.

Consider alternatives if you need:

• Ultra-light apps (<5MB) → Native iOS/Android, PWA
• Embedded/IoT apps → engine overhead (3–4MB) is too high
• Extreme performance & control → Native APIs

Flutter Web: Smaller by Design

Unlike mobile, Flutter Web apps can hit 2–5 MB for initial loads:

• Aggressive tree shaking
• Dynamic code splitting
• Browser caching & compression

If storage is critical, and your UX allows it, Flutter Web or PWAs may fit better.

What You Can Realistically Achieve

• Production apps: 8–15MB (optimized) vs. 25–40MB (default)
• Reduction potential: 50–70% with full optimization
• Business wins:
• Faster downloads
• Better adoption in bandwidth-limited regions
• Lower uninstall rates due to storage pressure

Final Takeaway

A 1MB Flutter app is a myth — but lean, optimized apps are very real.

By splitting ABIs, trimming assets, enabling shrinking, and auditing dependencies, you can cut app size by half or more.

The real goal isn't hitting a random "1 MB" number.
It's building apps that users download quickly, install confidently, and keep using.

What's your experience? Have you achieved significant Flutter app size reductions in production? Share your optimization wins and the real-world impact on user acquisition in the comments.