📱 Mobile

Silent Push / Background Notification

silent push · background notification · silent notification · content-available push · data-only push · background push

Definition

A silent push is a push notification carrying a background-execution flag: it is never shown to the person, but it wakes the app so it can run a background data sync.

Why silent push exists

The main job of a silent push is to remove the delay when the app opens. With no background sync,
the app makes a server request at launch and shows content only once the response arrives. With a
silent push the data is already cached: the home screen with personalized recommendations, or the
promotions catalogue, loads instantly.

In e-commerce it is used for:

Preloading a personalized feed — current recommendations are ready by the moment the app opens
Refreshing stock levels — availability is accurate without an explicit request
Syncing remote config — new personalization parameters apply before the next session
Updating the cart — when the person added items on the website

Technical limits

Platform	Mechanism	Limit
iOS (APNs)	`content-available: 1`	Throttled by the system; ~30 seconds to process
Android (FCM)	`data`-only message	The app must be in the background, not terminated

Important: iOS may ignore a silent push in Low Power Mode, or when the app has not been opened
for several days. Do not rely on silent push for important updates — use it only as a UX
optimisation.

How it differs from Background Fetch

A silent push wakes the app on the server’s initiative. Background Fetch is a scheduled
background load on the operating system’s initiative: iOS decides when to grant processor time.
Use a silent push when data must be refreshed at a specific moment; use Background Fetch for
regular background sync where exact timing does not matter.

Silent push and personalization analytics

One nuance matters: a silent push is never displayed as a notification, so it does not appear in
push delivery rate or open rate metrics. If part of your personalization pipeline runs on silent
pushes — refreshing the user profile before the app opens, for example — make sure that step is
recorded in your own application logs. Standard push channel metrics will not show it.

Frequently asked questions

How does a silent push differ from an ordinary push notification?

An ordinary push shows a banner, a sound and/or a badge — the person sees it. A silent push arrives quietly and invisibly, waking only the app process in the background. The person never knows it arrived, but at the next launch they see already refreshed content.

How do you send a silent push on iOS?

In the APNs payload, set the content-available flag to 1 and remove the alert field, so no banner is drawn. iOS wakes the app and calls application:didReceiveRemoteNotification:fetchCompletionHandler:. The app gets roughly 30 seconds to finish its work.

Is silent push delivery guaranteed?

No. iOS is entitled to throttle or drop silent pushes — in Low Power Mode, on a weak connection, or when an app sends them too often. Never build critical business logic on a silent push as if it were a guaranteed transport.

Does a silent push need the person's permission?

On iOS, no. A silent push does not require an explicit opt-in through UNAuthorizationOptions. Android behaves the same way — background messages over FCM do not ask for notification permission.