Understanding App Lifecycle Events in Flutter and React Native

App lifecycle events, including those in Flutter and React Native, are critical for tasks like saving state, pausing animations, handling background tasks, or managing resources. Whether you’re building with Flutter or React Native, understanding the lifecycle of your app is essential for delivering a responsive and battery-efficient user experience.

In this post, you’ll learn how lifecycle events work in both Flutter and React Native, what events to watch for, and how to respond to them properly in 2025.

🚦 What Are App Lifecycle Events?

App lifecycle events refer to transitions between an app’s active, inactive, background, and terminated states. Common use cases include:

• Saving data when the app goes to background
• Pausing video/audio playback
• Refreshing state when the app resumes
• Releasing resources on termination

📱 Flutter App Lifecycle Events

Flutter provides WidgetsBindingObserver to listen to app lifecycle changes.

🔧 How to Use:

class MyAppLifecycleObserver extends StatefulWidget {
  @override
  _MyAppLifecycleObserverState createState() => _MyAppLifecycleObserverState();
}

class _MyAppLifecycleObserverState extends State
    with WidgetsBindingObserver {
  @override
  void initState() {
    super.initState();
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  @override
  void didChangeAppLifecycleState(AppLifecycleState state) {
    if (state == AppLifecycleState.paused) {
      print('App moved to background');
    } else if (state == AppLifecycleState.resumed) {
      print('App resumed');
    }
  }

  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

🔁 Key States in Flutter:

• resumed – App is visible and responding to user input
• inactive – App is in an inactive state (e.g., a phone call)
• paused – App is not visible to the user
• detached – App is still hosted on the engine but detached from any view

⚛️ React Native App Lifecycle Events

In React Native, the AppState API allows you to track app state changes.

🔧 How to Use:

import { useEffect, useState } from 'react';
import { AppState, AppStateStatus } from 'react-native';
const useAppLifecycle = () => {
  const [appState, setAppState] = useState(AppState.currentState);
  useEffect(() => {
    const subscription = AppState.addEventListener('change', setAppState);
    return () => {
      subscription.remove();
    };
  }, []);
  return appState;
};

You can use this inside components to handle tasks like pausing timers, syncing data, or triggering animations.

🔁 Key States in React Native:

• active – App is running in the foreground
• background – App is in the background
• inactive – Transitory state (e.g., switching apps on iOS)

📘 Learn more: React Native AppState Docs

🔄 Real-World Use Cases

Use Case	Lifecycle Event	Framework
Pause video playback	paused, background	Flutter & RN
Save draft data	paused, inactive	Flutter & RN
Re-authenticate session	resumed, active	Flutter & RN
Track app open count	resumed, active	Flutter & RN
Clean up sockets	inactive, background	Flutter & RN

✅ Best Practices

• Always unsubscribe listeners to avoid memory leaks
• Don’t rely on lifecycle events for critical data saves — use them to supplement user actions
• Test thoroughly across Android/iOS as lifecycle behavior may differ
• Combine with push notifications, analytics, or background tasks for better UX

🧠 Final Thoughts

Understanding app lifecycle events is key to building responsive, efficient, and user-friendly mobile apps. Whether you’re using Flutter or React Native, handling lifecycle transitions properly helps improve performance, preserve user data, and provide a seamless experience.

Make lifecycle awareness part of your development checklist — especially in apps that handle media, background sync, or long user sessions.