Firebase Push Notifications in Flutter – Complete 2026 Guide

Firebase Cloud Messaging (FCM) is the standard push notification service for Flutter apps. This guide covers every notification state with production-ready code.

Setup

# pubspec.yaml
dependencies:
  firebase_core: ^3.3.0
  firebase_messaging: ^15.1.0
  flutter_local_notifications: ^17.2.1

Android Configuration

<!-- AndroidManifest.xml inside <application> -->
<meta-data
    android:name="com.google.firebase.messaging.default_notification_channel_id"
    android:value="high_importance_channel" />

The Notification Service

@pragma('vm:entry-point')
Future<void> _bgHandler(RemoteMessage message) async {
  await Firebase.initializeApp();
  await NotificationService.instance.showLocal(message);
}

class NotificationService {
  NotificationService._();
  static final instance = NotificationService._();

  final _fcm   = FirebaseMessaging.instance;
  final _local = FlutterLocalNotificationsPlugin();

  Future<void> init() async {
    FirebaseMessaging.onBackgroundMessage(_bgHandler);
    await _setupLocalNotifications();
    await _requestPermission();
    await _setupHandlers();
  }

  Future<void> _requestPermission() async {
    await _fcm.requestPermission(alert: true, badge: true, sound: true);
    await _fcm.setForegroundNotificationPresentationOptions(
      alert: true, badge: true, sound: true,
    );
  }

  Future<void> _setupLocalNotifications() async {
    const android = AndroidInitializationSettings('@drawable/ic_notification');
    const ios     = DarwinInitializationSettings(
      requestAlertPermission: false,
      requestBadgePermission: false,
      requestSoundPermission: false,
    );
    await _local.initialize(
      const InitializationSettings(android: android, iOS: ios),
      onDidReceiveNotificationResponse: _onTap,
    );

    const channel = AndroidNotificationChannel(
      'high_importance_channel',
      'High Importance Notifications',
      importance: Importance.high,
    );
    await _local
        .resolvePlatformSpecificImplementation<AndroidFlutterLocalNotificationsPlugin>()
        ?.createNotificationChannel(channel);
  }

  Future<void> _setupHandlers() async {
    FirebaseMessaging.onMessage.listen(showLocal);
    FirebaseMessaging.onMessageOpenedApp.listen(_navigate);
    final initial = await _fcm.getInitialMessage();
    if (initial != null) _navigate(initial);
  }

  Future<void> showLocal(RemoteMessage msg) async {
    final n = msg.notification;
    if (n == null) return;
    await _local.show(
      n.hashCode, n.title, n.body,
      const NotificationDetails(
        android: AndroidNotificationDetails(
          'high_importance_channel', 'High Importance Notifications',
          importance: Importance.high, priority: Priority.high,
        ),
        iOS: DarwinNotificationDetails(presentAlert: true, presentSound: true),
      ),
      payload: msg.data['route'],
    );
  }

  void _onTap(NotificationResponse r) {
    if (r.payload != null) _goTo(r.payload!);
  }

  void _navigate(RemoteMessage msg) {
    final route = msg.data['route'];
    if (route != null) _goTo(route);
  }

  void _goTo(String route) {
    debugPrint('Navigate to $route');
  }

  Future<String?> getToken() => _fcm.getToken();
  Future<void> subscribe(String topic) => _fcm.subscribeToTopic(topic);
}

Initialize in main.dart

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);
  await NotificationService.instance.init();
  runApp(const MyApp());
}

FCM Payload Structure

{
  "message": {
    "token": "device_token",
    "notification": { "title": "New Order", "body": "Order #1234 placed" },
    "data": { "route": "/orders/1234", "orderId": "1234" },
    "android": {
      "notification": { "channel_id": "high_importance_channel" }
    }
  }
}

Topics (Broadcast to Groups)

await NotificationService.instance.subscribe('all_users');
await NotificationService.instance.subscribe('flutter_devs');

Common Issues

No notification on Android — Check channel ID matches manifest. No foreground on iOS — Implement UNUserNotificationCenterDelegate. Android 13+ blocked — Request POST_NOTIFICATIONS permission. Token null — Wait for Firebase init before calling getToken().