All posts
Service Worker Generator: Cache Strategies for PWAs
August 15, 2026 · DevTools
service-worker
pwa
offline
cache
Progressive web apps rely on service workers to cache assets and serve offline fallbacks. Writing the install, activate, and fetch handlers from scratch is repetitive — especially when you only need a standard cache strategy.
The Service Worker Generator outputs a ready-to-copy sw.js plus a registration snippet for your main bundle.
Strategies
| Strategy | Behavior |
|---|---|
| Cache first | Return cached responses when available; update cache on network success |
| Network first | Try network, fall back to cache or offline page |
| Stale while revalidate | Serve cache immediately while refreshing in background |
Precache list
Add URLs (paths like /, /app.js, /styles.css) that should populate the cache during the install event. The generator emits a cache.addAll call with your list.
Offline fallback
Set a fallback URL (e.g. /offline.html) used when both network and cache miss.
Try it in the Service Worker Generator — no sign-up required.