Service workers have been having a moment. In March 2018, iOS Safari began including service workers — so all major browsers at this point support offline options. And this is more important than ever — 20% of adults in the United States are without Internet at home, leaving these individuals relying solely on a cellphone to access most information. This can include something as simple as checking a bank balance or something as tedious as searching for a job, or even researching illnesses.
Offline-supported applications are a necessity, and including a service worker is a great start. However, service workers alone will only get someone part of the way to a truly seamless online-to-offline experience. Caching assets is great, but without an internet connection you still can’t access new data or send any requests.