With Safari 18.5, included in macOS 15.5, Apple added Declarative Web Push, an updated method to deliver web-based push notifications even when a website isn't open. With Declarative Web Push, developers can display notifications without the need for a service worker, which preserves battery life for Web Push notifications.

Declarative Web Push is more energy efficient, and it's also more private and easier for developers to implement. It does not rely on JavaScript, instead using a standardized JSON format that lets browsers directly display notifications without additional code.

Declarative Web Push isn't subject to the same feature-breaking bugs and network issues as the standard web push, nor will anti-tracking prevention features disable it on websites that the user hasn't visited in some time.

Apple says that Declarative Web Push is backwards compatible with browser engines that haven't yet added support. End users do not need to do anything to see Declarative Web Pushes, as this is a behind-the-scenes feature for developers to implement.

Apple previously added support for Declarative Web Push on iPhone and iPad with the iOS 18.4 and iPadOS 18.4 updates. More information is available on Apple's WebKit blog.

Safari 18.5 is included in macOS 15.5, but the browser update is also available for Macs that are still running macOS Sonoma and macOS Ventura.

Source: Macrumors