Service workers are among the most exciting new technologies on the web. They allow modern web apps to store resources locally and provide offline functionality. However, if you’ve tried working with them, you’ll rapidly find that maintaining caches properly is a complex problem. This is where Workbox comes in. It is a set of build tools and libraries designed to make it easier to create service workers and hence easier to build offline apps. In simple terms, you tell it which resources you want to cache and it will generate the service worker code required to cache and update your resources. As you begin to build more complex sites with offline features, this abstraction is likely to make your life a lot easier.