Cloudflare edge cache TTL: edge vs browser, and what HIT/MISS tells you

TL;DR: A long edge TTL with a long browser TTL means a bad deploy is cached in two places, and purging the edge does not fix users whose browsers cached the old copy. # Edge cache TTL design Cloudflare caching has two TTLs that people constantly conflate: - Edge TTL: how long Cloudflare's edge keeps the response. - Browser TTL: how long the visitor's browser keeps the response (via Cache-Control).

Edge cache TTL design

Cloudflare caching has two TTLs that people constantly conflate:

• Edge TTL: how long Cloudflare's edge keeps the response.
• Browser TTL: how long the visitor's browser keeps the response (via Cache-Control).

A long edge TTL with a long browser TTL means a bad deploy is cached in two places, and purging the edge does not fix users whose browsers cached the old copy. Pair server-side purges with versioned asset URLs for anything you deploy often.

CF-Cache-Status

The CF-Cache-Status response header tells you what the edge did:

• HIT: served from edge cache. Your caching works.
• MISS: fetched from origin, now cached. Expected on first request after purge.
• EXPIRED: the cached copy aged out, refetched from origin.
• BYPASS: the response was not cached (Cache-Control said no, or a rule bypassed).
• DYNAMIC: Cloudflare did not attempt to cache (default for HTML and other dynamic content without a cache rule).

The failure modes

• "Caching is broken" when the header says DYNAMIC: Cloudflare is doing exactly what it was told; you need a Cache Rule to cache that content type.
• BYPASS on everything after adding a rule: check for conflicting rules (later non-terminating changes overwrite earlier ones in the same phase).
• MISS on every request: something varies the cache key per request (a cookie, a query param in the key, or no-cache headers from the origin).

Checklist

• Set edge and browser TTL separately and deliberately.
• Read CF-Cache-Status before changing anything; it names the problem.
• For deploys, prefer versioned URLs plus tag-based purges over purge-everything.

When to use

You hit exactly this: Cloudflare edge cache TTL: edge vs browser, and what HIT/MISS tells you in Cloudflare edge cache TTL.

When not to use

A different error, or the same symptom in a different tool. This page only covers the failure above.

Compatibility

Cloudflare edge cache TTL.

Verified against the live Cache concepts docs: edge vs browser TTL distinction, CF-Cache-Status values (HIT/MISS/EXPIRED/BYPASS/DYNAMIC), default cache behavior. Ref: https://developers.cloudflare.com/cache/concepts/cache-responses/