If your website uses external fonts, such as open source web fonts, you could cache them to be viewed offline with service workers. In this chapter, we are going to look at how to load fonts offline.
To get started with service workers, you will need to have the service worker experiment feature turned on in your browser settings. If you have not done this yet, refer to the Setting up service workers recipe of Chapter 1, Learning Service Worker Basics. Service workers only run across HTTPS. To find out how to set up a development environment to support this feature, refer to the following recipes of Chapter 1, Learning Service Worker Basics: Setting up GitHub pages for SSL, Setting up SSL for Windows, and Setting up SSL for Mac.