Products Web Progressive Web Apps Training Offline Quickstart One of the best features of Progressive Web Apps is their ability to function even when offline. This video explains how to use the service worker and Cache API to make a simple app work offline. Watch video on YouTube View slides on Google Docs Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 3.0 License, and code samples are licensed under the Apache 2.0 License. For details, see our Site Policies. Java is a registered trademark of Oracle and/or its affiliates. Last updated May 2, 2017.