Service worker is available in Safari 11.1, which shipped March 29, 2018 with iOS 11.3 and macOS 10.13.4.
Note:
- Service Worker + Cache API are both supported (Cache API is actually a pre-requisite for Service Worker support)
- There are some noticeable problems with Apple’s implementation of Service Worker
- No “Add to Home Screen” prompt
- No Push API
- No Background Sync