Your Flutter app gets push notifications while it's open, but nothing shows up once it's in the background or closed. This is one of the most common Firebase Cloud Messaging problems, and it almost always comes down to a handful of causes. Here they are, from most to least likely.

Quick checklist

The background handler is a top-level function with @pragma('vm:entry-point') .

FirebaseMessaging.onBackgroundMessage() is registered before runApp() .

The message has a notification block, or is data-only with high priority (Android) and content-available (iOS).

Notification permission is granted (Android 13+ and iOS both ask).

On iOS: Push Notifications and Background Modes → Remote notifications are enabled, and the APNs key is uploaded to Firebase.

You're testing on a real device in a release or profile build , and the app wasn't force-stopped.

1. Set up the background handler correctly

When your app isn't in the foreground, firebase_messaging runs your handler in a separate Dart isolate.…