0Hot reload and hot restart help you see changes in your app instantly without losing your work. They make app development faster and easier.
Hot reload: Press 'r' in terminal or click the lightning bolt in IDE. Hot restart: Press 'R' in terminal or click the restart button in IDE.
// After changing a button color // Press 'r' in terminal or click lightning bolt // The app updates color without restarting
// After adding a new variable or changing main() // Press 'R' in terminal or click restart button // The app restarts fresh with new code
This app shows a counter and a button. When you press the button, the number increases.
If you change the text style or button color and use hot reload, the app updates instantly without losing the counter value.
If you use hot restart, the app restarts and the counter resets to zero.
import 'package:flutter/material.dart'; void main() { runApp(const MyApp()); } class MyApp extends StatefulWidget { const MyApp({super.key}); @override State<MyApp> createState() => _MyAppState(); } class _MyAppState extends State<MyApp> { int counter = 0; @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( appBar: AppBar(title: const Text('Hot Reload Demo')), body: Center( child: Column( mainAxisAlignment: MainAxisAlignment.center, children: [ Text('Counter: $counter', style: const TextStyle(fontSize: 24)), const SizedBox(height: 20), ElevatedButton( onPressed: () => setState(() => counter++), child: const Text('Increment'), ), ], ), ), ), ); } }
Hot reload works best for UI and logic changes inside widgets.
Hot restart is needed if you change global variables or main() function.
Using hot reload saves time because you don't lose app state like form inputs or navigation.
Hot reload updates code quickly and keeps app state.
Hot restart restarts app and resets state.
Use hot reload for small changes and hot restart for big changes.
hot reload and hot restart in Flutter?int counter = 0;
void increment() {
counter++;
}
// After hot reload, what is the value of counter if increment() was called 3 times before reload?Pass the test and this pattern moves unknown strong while earning +1 Grip toward your certificate.