Understanding PWA Cache Strategies: Cache First, Network First, and Stale-While-Revalidate (Beginner-Friendly Guide)
Understanding PWA Cache Strategies: Cache First, Network First, and Stale-While-Revalidate (Beginner-Friendly Guide) Last updated: 2026/02/14 Among all PWA features, cache strategy is the part that confuses beginners the most. Service Workers make websites load faster, but they also introduce issues like: “The update didn’t apply” “The old data keeps showing” “The site won’t refresh” This article explains the three major caching strategies used in PWAs: Cache First, Network First, and Stale-While-Revalidate — in a way that even complete beginners can understand. What Is a Cache Strategy? A cache strategy simply defines: “Where should the browser get data from first — the network or the cache?” Because PWAs cache files locally, they can load extremely fast. But if the strategy is wrong, updates fail to appear and the user keeps seeing outdated content. ① Cache First Super fast — but rarely updates. How it works Check the cache first If cached, show it immediately If not cached, fetch from the network and save it Advantages Extremely fast after the first load Great for offline-friendly apps Disadvantages Updates often fail to appear Developers must carefully manage cache invalidation This strategy is not suitable for blogs or frequently updated content. ② Network First […]
