What are Push Notifications?

Push notifications are a communication channel built into every mobile device sold today.
Push notifications allow apps to reach out to users with short messages that users may respond to.

Three things to know about push notifications:

  1. Push notifications are the first and often most important communications channel used by apps
  2. Nearly every major app uses push notifications for transactions and re-engagement.
  3. Push notification technology is rapidly evolving from a simple message delivery system to a rich and interactive medium
iOS Example
An example of a push notification
Android Example
An example of a push notification

About Push

Users today have a hard time remembering what apps they even have on their device. Notifications help these services deliver timely and relevant information to users, and in doing so, staying top of mind.

A recent study showed that mobile users receive an average of 63.5 notifications per day, with most notifications coming from messaging and email applications.

Push notifications at their core are simply a way of alerting users to information that they have opted-in to from apps and services. Notifications encompass nearly every possible use case and type of service, including other communications mediums like email, SMS, and VoIP.

Three basic types of notifications: Transactional, System, and User notifications.

Transactional Notifications

Transactional notifications are used to notify users of events. For example, notifying a user that a package has shipped or that their flight is delayed.

System Notifications

System notifications are used to tell users about new product features or opportunities. For example, notifying a user of a new product feature, or of a holiday discount.

User Notifications

User notifications are used to notify users of new messages from their friends, such as in an e-mail or social networking application.

Best Practices

Permission Messages and Opt-Ins

A key element of notifications is that users must opt-in to receiving them. Given the quantity of notifications most users receive, many users choose to opt-out of receiving more unless there is a compelling value to the notifications.

The easiest way for an application to maximize opt-in rate is to explain the value of notifications prior to prompting for notification permissions.

Using Permission Messages prior to showing a device Permission Requests is a best practice because Permission Messages increase the likelihood users will stay subscribed to your push notifications and find value in them. Permission Messages do three things:

  1. Inform a user of the value of subscribing to push notifications.
  2. Capture user intent with buttons like 'Enable' and 'No Thanks'.
  3. Trigger a Permission Request, if user indicates intent.

If a user dismisses a Permission Message, the app can still present them the option later on, once the user has more actively engaged with it.

Permission Messages let apps communicate value before a Permission Request
Android Example
After the user opts-in, the Permission Request dialog is shown

The Right Message at the Right Time

According to a recent study, notifications can frequently be considered an interruption:

“Participants reported that mobile messaging and email apps interrupted them in almost 50% of cases”

Despite their interruptive effects, a high volume of relevant or personal notifications actually has positive effects --

“Receiving more messages is significantly correlated with increased feelings of being connected with others ... Overall this implies that while these services are at times interrupting and overwhelming, the fact that they help users to keep in touch with friends, family and others appears to also have positive effects.”

Scheduling notifications intelligently plays a major role in increasing the likelihood of a user interacting with a notification, and improving the overall user experience. Notifications from messaging and social networking applications should generally be sent immediately, while other notifications are frequently best delayed until the user is less likely to be interrupted.

Receiving more messages is significantly correlated with increased feelings of being connected with others. 

In February 2016, OneSignal ran a study to determine the best times to send a notification based on application category.

The conclusion of the study was that the category of an application plays a major role in determining the best time to send notifications to users. Here is a summary of the categories and times that were uncovered:

8 AM 9 AM 10 AM 11 AM 12 PM 1 PM 2 PM 3 PM 4 PM 5 PM 6 PM 7 PM 8 PM 9 PM 10 PM 11 PM
Health/Fitness 8 AM
Entertainment 10 PM
Education 4 PM
Games 11 AM — 1 PM
Travel 3 PM — 7 PM
Social 10 AM — 11 PM
Figure optimal times
Optimal delivery times by app category, according to a OneSignal study

Technical Details

Platform Support & History

Push notifications were originally introduced for Android and iOS devices in 2009, and have rapidly spread to other platforms.

2009 — Apple iOS and Google Android add support

2010 — Blackberry and Microsoft Windows Phone 7 add support

2013 — Apple announces that 7 billion notifications are being sent to iOS devices each day.

2016 — Apple rolls out major additions to push notification capabilities to iOS with their iOS 10 release.

While all notification platforms support receiving short messages from applications, some platforms support additional features including custom sounds, images, or contextual buttons within the notification itself.

Custom Title Custom Icon Custom Sound Trigger Code Large Images Custom UI Action Buttons
iOS check_circle 1 check_circle check_circle check_circle 2 check_circle 2 check_circle
Android check_circle check_circle check_circle check_circle check_circle check_circle check_circle
Windows Phone check_circle check_circle check_circle check_circle check_circle check_circle check_circle
Amazon Fire check_circle check_circle check_circle check_circle check_circle check_circle check_circle
Web Push (Chrome & Firefox) check_circle check_circle check_circle check_circle check_circle
Figure optimal times
1 Including subtitle 2 iOS 10+