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Service Workers: Offline Now(ish)!

Alex Russell (Google)
Average rating: ****.
(4.54, 13 ratings)

HTML Service Workers present new opportunities — and challenges — for mobile and offline application development on the web by offering the equivalent of a programmable client-side proxy for network traffic from your application.

This talk by the editor of the Service Worker spec explores:

  • The install process and the First Load Problem™
  • The programmable cache model:
    - Populating caches
    - Background updates
    - Matching cache entries to Requests
  • Request-by-request network control:
    - What requests get set to which SW? What about iframes?
    - Cross-origin vs. Same-origin opportunities
    - What can be cached, where, how much, and for how long
    - Request routing
    - Composing SW-based apps with `importScripts()` and event handlers
  • The Offline-First application model:
    - How apps differ from pages
    - Thinking about shell vs. content; what’s in a URL?
  • The application upgrade process:
    - Wait-for-restart vs. immediate takeover
    - Upgrade gotchas, version skew, and schema migrations
  • Performance considerations:
    - Will using SWs slow my app down?
    - Network vs. disk performance
    - Request ordering and priority
    - Streaming response content
    - SPDY/HTTP2.0 and Service Workers
    - Memory concerns
    - Interaction with the browser preload-scanner
  • Future Service Worker-based APIs
Photo of Alex Russell

Alex Russell


Alex Russell works on Chrome and the broader web platform at Google San Francisco. He serves on the W3C Technical Architecture group and TC39, the standards body for JavaScript.