Push Notification

A push notification is a short message an app or website sends to a device’s lock screen and notification shade, even when the user does not have the app open. To receive them, the user has to give the app permission to send notifications.

What is a push notification?

A push goes out from the company’s server through a relay service run by the operating system. On Apple devices, the Apple Push Notification service (APNs) delivers notifications to the user’s device. Apps can also create local notifications on their own, triggered by time or location, with no server involved (Apple Developer, User Notifications, accessed October 2026). On Android, the usual service is Firebase Cloud Messaging (FCM), Google’s cross-platform messaging solution (Firebase, Cloud Messaging, accessed October 2026).

By purpose, pushes fall into two types:

• Transactional notifications: order delivered, booking code, new message. Users are waiting for these.
• Marketing notifications: promotions, new products, abandoned cart reminders. Send too many of these and users turn off notifications or delete the app.

How notification permission has changed

Android. Starting with Android 13, notifications require the POST_NOTIFICATIONS permission. Apps newly installed on devices running Android 13 or higher have notifications off by default and must ask for, and be granted, permission before they can send any (Android Developers, Notification runtime permission, updated October 2026).

iOS. The first time an app asks for permission, the system prompts the user and records the answer. Apple recommends asking in context, when the user understands what the notifications are for, instead of asking on the very first app open. Apps can also use provisional authorization: notifications arrive quietly and appear only in the Notification Center history, and the user then decides whether to keep or turn them off (Apple Developer, Asking permission to use notifications, accessed October 2026).

Guideline 4.5.4 of the App Review Guidelines says push notifications must not be used for promotions or direct marketing unless the user has explicitly opted in through consent language shown in the app’s UI, and the app offers a way to opt out inside the app (Apple App Review Guidelines, accessed October 2026).

Web push. Since iOS and iPadOS 16.4, web apps added to the Home Screen can send Web Push notifications (WebKit, February 2023).

Example (hypothetical)

A movie ticketing app has 100,000 active users, and 40% of them allow notifications. On a Thursday, the app sends a push about early screenings of a new film to those 40,000 people.

• Open rate of 3%: 1,200 people open the notification.
• 15% of them buy a ticket: 180 orders.
• Average ticket price of 90,000 VND: revenue of 16,200,000 VND.

To grow that number, the better lever is usually raising the opt-in rate (40%) and sending to the people who tend to watch that genre, not sending more often.

Push notification vs. in-app message vs. SMS

Push is the main channel for re-engagement and is often paired with a deep link that opens the right screen.

Frequently asked questions

When should an app ask for notification permission?

Right after the user does something where a notification is immediately useful: placing an order, following a product, signing up for price drop alerts. At that point the reason for asking is much clearer than on the first screen.

Which metrics show whether push is working?

Opt-in rate, open rate, conversion after opening, and the rate at which people turn off notifications or uninstall after each send. That last one tells you whether you are sending too much, and it directly affects your retention rate.

If you want to plan push alongside paid channels for users who are about to churn, see Adtek’s App User Acquisition solution or reach Adtek through the contact page.