FCM is the new version of GCM under the Firebase brand. It inherits GCM’s core infrastructure, with new SDKs to make Cloud Messaging development easier.
Benefits of upgrading to FCM SDK include:
- Simpler client development. You no longer have to write your own registration or subscription retry logic.
- An out-of-the-box notification solution. You can use Firebase Notifications, a serverless notifications solution with a web console that lets anyone send notifications to target specific audiences based on Firebase Analytics insights.
To upgrade from GCM SDKs to FCM SDKs, see the guides for migrating Android and iOS apps.
If you'd like to see the differences between GCM and FCM, visit the Firebase documentation - FAQ section.
