Push Notification Payload Builder

A Web Push payload is a JSON object sent from your server to a push service (Google FCM, Apple APNs, Mozilla) which delivers it to the user's browser. The payload defines title, body, icon, badge, actions, and data. It follows the Web Push Protocol (RFC 8030) and is encrypted with VAPID authentication.

VAPID (Voluntary Application Server Identification) is a protocol that lets push services identify your server. You generate a VAPID key pair — the public key is shared with the browser during subscription, and the private key signs your push requests. This prevents other servers from sending push messages to your subscribers.

Actions are buttons shown below the notification body. Each action has an action ID, a title label, and optionally an icon. When a user clicks an action, the service worker receives a notificationclick event with the action ID. Actions only show in browsers that support them (Chrome on Android, desktop Chrome/Edge). Limited to 2-3 actions on most platforms.

icon: the small app icon shown next to the notification title (48x48 or larger). badge: a tiny monochrome icon shown in the notification bar on Android to represent your app (96x96 monochrome PNG). image: a large image displayed inside the notification body (landscape ratio, ~360x180px). All three should be absolute HTTPS URLs.

TTL specifies how long (in seconds) the push service should store and retry delivery if the device is offline. TTL: 0 means deliver immediately or drop. TTL: 3600 means retry for up to 1 hour. Max TTL varies by push service — FCM allows up to 2419200 (28 days). Set TTL based on how time-sensitive your notification is.