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Web push notification

A web push notification is a message delivered by the browser through the Push API and a service worker, after the user grants explicit permission. It reaches people when they are not on your site — no app install and no email address required. On iOS, it only works for web apps added to the Home Screen (Safari 16.4+).

Updated 8 Jul 20263 min readBy fromHello
Key takeaways
  • Web push requires an explicit permission grant — the browser, not you, controls the prompt and the revocation.
  • Delivery runs through the Push API and a service worker, so notifications arrive even when your site is closed.
  • On iOS, web push only works for web apps added to the Home Screen, starting with Safari 16.4.

How does a web push notification work?

The flow has three parts. Your page asks for notification permission; if the user accepts, the browser creates a push subscription through the Push API and returns an endpoint on a push service operated by the browser vendor (Google, Mozilla, Apple). Your server sends a payload to that endpoint, signed with your VAPID keys. The browser then wakes your service worker — a script that runs without an open tab — which displays the notification. Nothing is sent before the user opts in, and the permission can be revoked at browser level at any time.

Web push and the three pieces that make it work.

Does web push work on iOS and Safari?

Yes, with a caveat that catches most teams. Since Safari 16.4 (March 2023), iOS and iPadOS deliver web push only to web apps the user has added to the Home Screen — a regular Safari tab cannot subscribe. The permission request must also follow a user gesture, such as a button tap. On macOS, Safari has supported web push in the normal browser since version 16.1. The practical consequence: on iPhone, web push is a channel for your most committed users, not a broad-reach one.

When should a small team use web push?

Web push earns its place when you need to reach users off-site without an email address: trial-expiry nudges, setup reminders, alerts on events a user chose to follow. It pairs naturally with in-app messages — in-app speaks to users while they are in the product, push brings them back when they are not. For how the two channels fit into one program, see the guide to web push and in-app messaging. Tools such as OneSignal and Novu exist largely to manage subscriptions and delivery for you.

What are the limits of web push?

  • Permission is fragile: ask too early and users hit deny, which is near-permanent — most teams gate the browser prompt behind their own UI first.
  • Delivery is not guaranteed: notifications go through the browser vendor's push service and can be throttled, collapsed, or dropped on unreachable devices.
  • No inbox: a dismissed notification is gone, so anything durable also belongs in email or in-app.
  • Reach is uneven: desktop Chrome and Android work well; on iPhone, only installed web apps qualify.
Sources
FAQ

Common questions

  • What's the difference between a web push notification and an in-app message?

    Web push reaches users off-site through the browser's notification system and requires an explicit permission grant. An in-app message renders inside your product while the user is there, with no browser permission needed. Most teams use push to bring users back and in-app to guide them once they arrive.

  • Do web push notifications work when the browser is closed?

    On Android and on iOS installed web apps, yes — push rides the operating system's notification pipeline. On desktop, the browser process must be running, though no tab of your site needs to be open. If a device is offline, the push service holds recent messages and delivers them on reconnect, within the message's time-to-live.

  • Do users need to install an app to get web push?

    No native app is needed. On desktop and Android, any supported browser can subscribe from your website. iOS is the exception: the user must first add your site to the Home Screen as a web app (Safari 16.4 or later) before the permission prompt is even available.

  • Does web push need an email address or phone number?

    No. A push subscription is anonymous by default — it identifies a browser on a device, not a person. That makes it useful before signup, but subscriptions also die with the browser profile, so treat web push as a complement to owned identifiers, not a replacement.

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