Caching
Headers that tell an intermediary what it may store and for how long. The oldest, best-specified corner of HTTP, and the one API providers most routinely ignore.
16 headers, ordered by how many providers in the catalog declare them.
Cache-Control
109 providers
regulated
3 spellings
The oldest well-specified corner of HTTP, routinely ignored by API providers, and carrying a technical-safeguards obligation on responses with personal data.
Expires
20 providers
2 spellings
The Expires HTTP header — caching, RFC 9111, declared by 20 providers in the API Evangelist catalog.
Pragma
17 providers
2 spellings
The Pragma HTTP header — caching, RFC 9111, declared by 17 providers in the API Evangelist catalog.
Vary
12 providers
2 spellings
The Vary HTTP header — caching, RFC 9110, declared by 12 providers in the API Evangelist catalog.
Surrogate-Control
1 providers
The Surrogate-Control HTTP header — caching, declared by 1 providers in the API Evangelist catalog.
Age
1 providers
The Age HTTP header — caching, RFC 9111, declared by 1 providers in the API Evangelist catalog.
Warning
The Warning HTTP header — caching, RFC 9111, not observed in the catalog.
Surrogate-Capability
The Surrogate-Capability HTTP header — caching, not observed in the catalog.
Refresh
The Refresh HTTP header — caching, not observed in the catalog.
Meter
The Meter HTTP header — caching, RFC 2227, not observed in the catalog.
Memento-Datetime
The Memento-Datetime HTTP header — caching, RFC 7089, not observed in the catalog.
CDN-Cache-Control
The CDN-Cache-Control HTTP header — caching, RFC 9213, not observed in the catalog.
Cache-Status
The Cache-Status HTTP header — caching, RFC 9211, not observed in the catalog.
Cache-Groups
The Cache-Groups HTTP header — caching, RFC 9875, not observed in the catalog.
Cache-Group-Invalidation
The Cache-Group-Invalidation HTTP header — caching, RFC 9875, not observed in the catalog.
AMP-Cache-Transform
The AMP-Cache-Transform HTTP header — caching, not observed in the catalog.