Every website and web app should have a service worker | Go Make Things

A service worker is a special JavaScript file that gets installed by a user’s web browser and saved locally.Any request that comes from the site—and any response it gets back—first goes through the service worker file. Service workers also have access to a special cache where they can save responses and assets locally.

Together, these features allow you to…Serve frequently accessed assets from your local cache instead of the network, reducing data usage and improving performance.

Provide access to critical information (or even your entire site or app) when the visitor goes offline.Prefetch important assets and API responses so they’re ready when the user needs them.Provide fallback assets in response to HTTP errors.In short, service workers allow you to build faster and more resilient web experiences.

Source: Every website and web app should have a service worker | Go Make Things