Most service worker code samples show only the happy path where the fetched resource will eventually be available, eg: self.addEventListener('fetch', event => { // Skip cross-origin requests, like those for Google Analytics. if (event.request.url.startsWith(self.location.origin)) { event.respondWith( caches.match(event.request).then(cachedResponse => { if (cachedResponse) { return cachedResponse; } return caches.open(RUNTIME).then(cache => { return fetch(event.request).then(response => { // Put … Continue reading Error handling for failed network requests with service workers →