Edge Caching for Dynamic Pages: What Actually Works
Caching pages at content delivery network edges even when they contain some personalized or changing content.
Marcus Adeyemi
Why does it matter?
Edge caching turns slow dynamic pages into fast ones, but only with careful rules about what varies per visitor.
What are the numbers?
- Cache keys determine what counts as the same page
- Vary headers tell caches which request headers change the response
- Purging content changes require cache invalidation
- Personalization user-specific fragments can be loaded separately
What should I do?
- Cache the shared page and load personal parts separately
- Define cache keys deliberately
- Set up purge hooks on content changes
- Watch for cookies that break caching
- Measure cache hit rates
What should I avoid?
Avoid:
- Caching pages containing another user's data
- Cookies that vary every response
- Manual purging only
- Long cache lifetimes with no invalidation
When should I get help?
Short answer Bring in help when dynamic sites need to survive traffic spikes.
Where this comes from
- Cloudflare Learning Center — What is a CDN?
- MDN Web Docs — HTTP caching
The figures and practices above come from the sources listed.
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Where to go next
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