Definition:

A push notification is a short message that an application or website sends to a device through the operating system or browser. It can appear while the application is closed or the user is not visiting the page, provided that the required permission has been granted.

These notifications may communicate messages, status changes, reminders, security alerts, news, or promotions. Not every push notification is advertising: many serve an operational or transactional function within a service.

How a push notification works

Delivery requires the application or browser to register the device or subscription with a notification service. That service acts as an intermediary between the system that creates the message and the device that should receive it. The sender does not deliver directly to a personal address, but to a technical identifier associated with the installation or subscription.

The basic process follows these stages:

Permission: the person accepts notifications in the app, browser, or device settings.
Registration: the system obtains an identifier or token and associates it with the relevant installation or subscription.
Preparation: the sender defines the content, recipients, priority, expiration, and message destination.
Delivery: a service such as Apple Push Notification Service, Firebase Cloud Messaging, or a browser push service transmits the notification.
Presentation: the operating system or browser decides how to display it according to permissions, settings, and device state.
Interaction: selecting it may open a specific screen, URL, or defined action; the user may also dismiss it without opening.

Delivery is not guaranteed in every case. The device may be turned off, offline, have revoked permissions, or apply battery and background restrictions. A token may also expire. Therefore, a sent, delivered, and opened message represent different states.

Types of push notifications

Notifications can be classified by their technical environment and by the purpose of the message. An organization may use several types, but each channel has its own permissions and capabilities.

Mobile push: originates from an installed application and is presented through Android, iOS, or another compatible system.
Web push: originates from an authorized website and may appear through the browser even when the page is not open.
Desktop notifications: are generated by applications or browsers on computers through operating-system mechanisms.
Transactional notifications: report specific operations such as a payment, delivery, booking, or account access.
Activity notifications: communicate messages, mentions, comments, status changes, or events related to service usage.
Promotional notifications: announce content, products, or offers and require particular control over consent, frequency, and relevance.

Progressive web applications may support web push when the browser and operating system provide the required interfaces. However, a PWA and a push notification are different concepts: the former is a type of web application, while the latter is a communication mechanism.

Managing push notifications

Management begins with a clear permission request connected to a specific benefit. Asking for authorization without explaining which messages will be sent may increase rejection. A valid subscription also does not mean that every frequency or type of content is appropriate. Permission can be limited or withdrawn through the application, browser, or device.

Segmentation can adapt messages according to preferences, language, relationship with the service, or previous actions. The data used must have a legitimate basis and remain current. Personalization does not require displaying sensitive information in an alert visible from a locked screen.

Priority, timing, expiration, and grouping also require control. An urgent alert may need different treatment from a promotion, while an obsolete message should not appear several hours later. Relevance depends on timing and context as well as copy.

Measuring push notifications

Measurement should separate technical events from outcomes. A dashboard may record sends, estimated deliveries, opens, clicks, or subsequent actions, but each platform defines and limits these metrics differently. Some deliveries or views cannot be confirmed individually.

Delivery: indicates which messages reached the service or device according to the available information.
Open or interaction: records when the user selects the notification or performs an associated action.
Conversion: measures the subsequent action related to the objective, such as completing a purchase or confirming an appointment.
Opt-outs and permissions: show deactivations, revocations, and the loss of valid subscriptions.
Frequency and fatigue: help relate message volume to response and abandonment.

Push notifications provide immediacy and direct access to a screen, but they can also interrupt and cause opt-outs when they lack value. Comparing them with email through a universal open rate is inaccurate. Their effectiveness depends on purpose, audience, permission, and measurement quality.