delay automatic service worker registration until load event

.changeset/swift-horses-march.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+Delay automatic service worker registration until load event

documentation/docs/07-service-workers.md

@@ -6,7 +6,7 @@ Service workers act as proxy servers that handle network requests inside your ap
 
 In SvelteKit, if you have a `src/service-worker.js` file (or `src/service-worker.ts`, or `src/service-worker/index.js`, etc) it will be built with Vite and automatically registered. You can disable automatic registration if you need to register the service worker with your own logic (e.g. prompt user for update, configure periodic updates, use `workbox`, etc).
 
-> You can change the location of your service worker and disable automatic registration in your [project configuration](/docs/configuration#files).
+> You can change the [location of your service worker](/docs/configuration#files) and [disable automatic registration](/docs/configuration#serviceworker) in your project configuration.
 
 Inside the service worker you have access to the [`$service-worker` module](/docs/modules#$service-worker).
 

packages/kit/src/runtime/server/page/render.js

@@ -182,7 +182,9 @@ export async function render_response({
 
 	const init_service_worker = `
 		if ('serviceWorker' in navigator) {
-			navigator.serviceWorker.register('${options.service_worker}');
+			addEventListener('load', () => {
+				navigator.serviceWorker.register('${options.service_worker}');
+			});
 		}
 	`;