This talk will cover 3 important parts of offline web apps - service workers, app cache and client-side storage. Service workers are cool new event-driven workers that enables our web apps to fully work offline, including intercepting and modifying requests, handle caching etc. Unfortunately it still doesn’t work in all browsers, so we still need App cache in some cases - older and not so great solution for offline caching but it works in all major browsers. For fully-functional web apps we need to have some kind of a client-side storage, last part of the talk will review Indexed DB, Web SQL and of course localStorage.