The Cache API allow authors to fully and conveniently manage their content caches for offline use. An origin can have multiple, named Cache objects which are accessible via workers and document scripts.
Docs: https://developer.mozilla.org/en-US/docs/Web/API/Cache https://developer.mozilla.org/en-US/docs/Web/API/CacheStorage
Samples: https://github.com/GoogleChrome/samples/blob/gh-pages/service-worker/README.md