Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.
Note: This feature is available in Web Workers.
The navigationPreload read-only property of the ServiceWorkerRegistration interface returns the NavigationPreloadManager associated with the current service worker registration.
The returned object allows resources managed by a service worker to be preemptively downloaded in parallel with service worker boot up.
An instance of NavigationPreloadManager.