When launched from the user’s home screen, service workers enable a Progressive Web App to load instantly, regardless of the network state.

A service worker, written in JavaScript, is like a client-side proxy and puts you in control of the cache and how to respond to resource requests. By pre-caching key resources you can eliminate the dependence on the network, ensuring an instant and reliable experience for your users.

53% of users will abandon a site if it takes longer than 3 seconds to load! And once loaded, users expect them to be fast—no janky scrolling or slow-to-respond interfaces.

Progressive Web Apps are installable and live on the user's home screen, without the need for an app store. They offer an immersive full screen experience with help from a web app manifest file and can even re-engage users with web push notifications.

The Web App Manifest allows you to control how your app appears and how it's launched. You can specify home screen icons, the page to load when the app is launched, screen orientation, and even whether or not to show the browser chrome.