Response Time Checker / Glossary
CDN cache hit
When a CDN has the page in its cache (a HIT), it answers from an edge near the visitor without asking your server. A MISS, DYNAMIC or BYPASS goes all the way to the origin.
How we measure it
We read the CDN's cache headers (cf-cache-status, x-cache, x-vercel-cache, age and others) on the final response.
What good looks like
HIT for pages that are the same for everyone, with an Age that shows the copy is reused.
How to improve it
- Send Cache-Control: public, s-maxage=… on pages that can be shared.
- Add a cache rule for HTML at the CDN (Cloudflare caches only static files by default).
- Avoid Set-Cookie and a broad Vary on cacheable pages.
Measure your site
Three cold samples, every phase, and a diagnosis of what is slow.
Open the Response Time Checker