Shrink Your Flutter App Like a Pro: 15 Proven Tips to Reduce APK & IPA Size

Is your Flutter app too large? A large app size can negatively impact user experience, leading to fewer installs and lower retention. This article provides 15 proven tips to drastically reduce your Flutter APK & IPA size, potentially by 40-70%.

Why Should You Care About App Size?

• Faster installs = More users
• Less device clutter = Happier retention
• Smaller apps = Higher Play Store rankings
• Essential in low-end and limited-data markets

1. Start by Measuring — Size First, Slice Later

Run the following commands to analyze your app's size:

• flutter build apk --analyze-size
• flutter build ios --analyze-size

Open the .json file in Dart DevTools to see a breakdown of assets, fonts, dependencies, native libs, and Dart code. Target the largest chunks first.

2. Remove Unused Packages, Fonts & Assets

Audit your pubspec.yaml file and remove any unnecessary dependencies, fonts, and assets. Only include essential fonts and styles.

3. Enable Tree Shaking for Icons

Icon packages can significantly increase your app size. Use the following command to remove unused icons:

flutter build apk --release --tree-shake-icons

This can save 5–8 MB.

4. Split APKs by ABI (Android only)

Why send all CPU architectures in one file? Use the following command:

flutter build apk --split-per-abi

This can result in a 60–70% size drop per APK, especially for devices with arm64-v8a.

5. iOS Tricks to Reduce IPA Size

• Avoid bundling static assets unless necessary.
• Strip debug symbols: flutter build ios --release
• Disable Bitcode (if not required).
• Remove dev-only logging/images.

6. Resize & Compress Images

Images are size hogs. Convert .png to .webp and resize to the device target size. Use tools like TinyPNG or ImageOptim.

7. Lazy Load Large Assets

Don’t bundle everything upfront. Use flutter_cache_manager to load images, videos, and docs only when needed. This also helps with app startup performance.

8. Use Deferred Components & On-Demand Modules

For large apps, modular delivery is a game-changer. Split onboarding, tutorials, and AR/ML features into separate modules.

9. Obfuscate Dart Code (Bonus: Smaller Size)

This improves security and reduces build size.

flutter build apk --release --obfuscate --split-debug-info=debug-info/

Keep your debug info safe!

10. Clean Builds Regularly

Old artifacts can lead to unnecessary bloat.

flutter clean

flutter pub get

flutter build apk --release

11. Prefer Code Over Packages (When Sensible)

Do you really need a package for 10 lines of Dart? Replacing bloated packages with native code or simple Dart logic can save hundreds of KBs.

12. Minimize Dependencies in Plugins

Audit plugin usage. Does the plugin import unnecessary platform code? Can it be replaced with a leaner one or pure Dart? Check .dart_tool/package_config.json for dependency bloat.

13. Avoid Material Icons If Not Used

Using MaterialApp with no icons? You’re still shipping them. Instead, use WidgetsApp(...) or selectively import icon sets.

14. Compress JSON or Large Strings

For big JSON strings, use GZIP compression and decode on device or move to remote config/lazy fetch.

15. Use Lottie Animations Sparingly

Those .json Lottie files are cool but can be bulky. Convert to .webp looped animations if performance or size is an issue.

Optimize for reality, not perfection. A conscious balance between size, performance, and user experience is key. Small apps convert better, retain longer, and feel snappier.