Service workers & PWAs

What you'll learn

• The service worker lifecycle, the bits that bite people
• Intercepting fetch and shaping responses
• Caching strategies — and when each one is wrong
• The web app manifest, install prompts, and what they actually do
• Push notifications and background sync, demystified
• Debugging workers when nothing seems to update

1. 01
   What a PWA is in 2026

   Installable, capable, network-aware — and what it isn't.
   13 min
2. 02
   The service worker lifecycle

   install, activate, fetch — and the states in between that confuse everyone.
   16 min
3. 03
   Registering and updating workers

   Why your changes don't show up, and how to make them.
   14 min
4. 04
   Fetch interception

   respondWith, the Request/Response duo, and the cost of getting it wrong.
   15 min
5. 05
   Caching strategies

   cache-first, network-first, stale-while-revalidate — pick by intent.
   17 min
6. 06
   The web app manifest

   Icons, names, scope, display modes, and what each line buys.
   12 min
7. 07
   Install prompts

   beforeinstallprompt, the criteria the browser checks, and the UX of asking.
   13 min
8. 08
   Push and background sync

   Notifications and queued work — what's reliable, what isn't.
   16 min
9. 09
   Offline-first design

   Designing UI that admits the network might not be there.
   14 min
10. 10
    Workbox without the magic

    What Workbox actually generates, and the cost of pretending it's free.
    14 min
11. 11
    Debugging service workers

    DevTools Application panel, the unregister button, and the order to check things.
    13 min