How to increase Flutter app performance

Improving the performance of a Flutter app involves optimizing rendering, reducing unnecessary rebuilds, minimizing resource usage, and more. Here’s a comprehensive list of Flutter performance optimization techniques, grouped into categories for clarity:

1. Rendering Performance

Use const constructors

• Reduces widget rebuilds and improves performance.

const Text('Hello');

Minimize rebuilds

• Use const, final, Provider, or ValueNotifier to isolate widgets that don’t need to rebuild.
• Use builder pattern (ListView.builder, AnimatedBuilder) to build only visible widgets.

Avoid rebuilding the whole widget tree

• Use StatefulWidget only where needed.
• Extract widgets into smaller components.

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2. Efficient State Management

Choose the right state management

• Use efficient state management libraries like:
  • Provider
  • Riverpod
  • Bloc / Cubit
  • GetX (lightweight, fast)
• Avoid rebuilding the whole tree for minor UI changes.

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3. Reduce Layout Passes

Avoid deep widget trees

• Overly nested widgets slow down rendering. Refactor complex UI layouts into simpler ones.

Use const and RepaintBoundary

• Wrap widgets that shouldn’t repaint with RepaintBoundary to isolate them.

RepaintBoundary(
  child: YourWidget(),
)

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4. Image Optimization

Use compressed and resized images

• Use WebP or JPEG formats.
• Resize images to the needed resolution before bundling.

Use CachedNetworkImage

• Prevents repeated downloads and improves image load time.

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5. List & Grid Performance

Use ListView.builder / GridView.builder

• Builds only visible items.
• Avoid ListView(children: [...]) for large lists.

Use keys

• Use ValueKey, ObjectKey, or UniqueKey to help Flutter understand widget identity.

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6. Memory and Garbage Collection

Dispose controllers

• Always dispose of:
  • TextEditingController
  • AnimationController
  • StreamSubscription

@override
void dispose() {
  _controller.dispose();
  super.dispose();
}

Avoid memory leaks

• Don’t retain large data sets in memory unnecessarily.
• Use lazy loading (pagination) for lists.

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7. Profiling and Debugging Tools

Use Flutter DevTools

• Performance tab: analyze frame rendering.
• Memory tab: spot leaks or memory bloat.
• CPU tab: identify expensive operations.

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8. Avoid Anti-Patterns

Anti-Pattern	Better Practice
setState() on large trees	Use scoped state updates
Large widget trees in one file	Break into smaller components
Synchronous long operations	Use compute() for expensive tasks

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9. Async Optimization

Use compute() for expensive tasks

• Offload heavy work to another isolate.

final result = await compute(expensiveFunction, data);

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10. Release Build & Code Shrinking

Always test in release mode

• Debug mode is slower.

flutter run --release

Enable code shrinking (Proguard)

• For Android: Use R8 to shrink and optimize code.

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Bonus Tips

• Use flutter analyze to find issues.
• Use flutter doctor to ensure environment is optimized.
• Reduce package bloat — avoid unused packages.