Service Worker Introduction

What's a service worker?

A service worker is a script which runs in the background of a browser and can:

• intercept and handle network requests
• create custom requests and responses
• cache requests/responses and store data
• serve cached responses and data when offline
• send push notifications
• synchronise data in the background

The service worker only needs a web page to be created. Because it runs in the background (worker context) it has no access to the document.

Code snippets

All code snippets are written in ES6 for brevity, but should be transpiled to or written in ES5 for proper browser support.

Resources

• Service Workers - W3C Working Draft
• Is Service Worker Ready?
• HTML5Rocks' Introduction to Service Worker
• MDN's Using Service Workers
• Jake Archibald's Offline Cookbook
• Mozilla's Service Workers Cookbook
• Google Chrome's Service Worker Recipes
• Matthew Gaunt's Service Worker with Push Notifications
• Push API - W3C Working Draft
• WHATWG's Web Notification API (living spec)
• WICG's Background Sync (draft spec)
• Google Developers' Introduction to Background Sync
• UpUp - Plugin to easily configure Service Worker