Response consistency

Validates that a resource’s caching-adjacent behavior is internally consistent.

Conditional requests

Re-requests the resource with If-None-Match/If-Modified-Since set from its own ETag/Last-Modified, and expects 304 Not Modified back.

Finding	Severity	Meaning
Conditional request not honored	low	A request matching the resource’s own validator got a non-304 status — the origin/cache isn’t revalidating correctly, forcing full re-transfers

Redirect caching

Checks whether a redirect response (301/302/303/307/308) is cacheable and, if so, whether it carries explicit freshness.

Finding	Severity	Meaning
Redirect cached with only heuristic freshness	low	The redirect is cacheable by default status semantics but has no explicit max-age/s-maxage/Expires — caches may apply their own heuristic TTL, which can outlive the redirect’s intended lifetime
Conditional request not honored	low	A request with If-None-Match/If-Modified-Since matching the resource’s own validator got something other than 304 Not Modified, forcing a full re-transfer
Unstable ETag validator	low	Two consecutive requests returned identical bodies but different ETags, so no later If-None-Match can ever match. Checked with one extra request, and only when the response has an ETag