What Is Push Notifications?
Push notifications are messages sent from a server to a user's device, appearing even when the app isn't open. They re-engage users, deliver time-sensitive information, and drive retention. iOS uses APNs (Apple Push Notification service), Android uses FCM (Firebase Cloud Messaging).
How Push Notifications Works
Server sends notification payload to APNs/FCM → service delivers to device → user sees notification on lock screen → tapping opens the app to specific content (deep link). Rich notifications include images, action buttons, and grouped threading. Web Push API brings notifications to browsers too.
Key Concepts
- APNs — Apple Push Notification service — requires certificates and provisioning profiles
- FCM — Firebase Cloud Messaging — handles Android and iOS push delivery through one API
- Notification Channels — Android 8+ groups notifications by type — users control which categories they receive
- Permission Prompting — Ask for notification permission at the right moment — after the user sees value, not on first launch
Frequently Asked Questions
How do I avoid annoying users with notifications?
Send relevant, timely, actionable notifications. Let users control frequency and categories. Never send promotional pushes without consent. A single annoying notification can cause an app uninstall.