Header category
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
160 provider declarations
| Header | Providers | Status | |
|---|---|---|---|
| Cache-Control | 109 | permanent | regulated |
| Expires | 20 | permanent | |
| Pragma | 17 | deprecated | |
| Vary | 12 | permanent | |
| Surrogate-Control | 1 | provisional | |
| Age | 1 | permanent | |
| Cache-Groups | — | permanent | |
| Cache-Group-Invalidation | — | permanent | |
| AMP-Cache-Transform | — | provisional | |
| Surrogate-Capability | — | provisional | |
| Refresh | — | permanent | |
| Meter | — | permanent | |
| Memento-Datetime | — | permanent | |
| CDN-Cache-Control | — | permanent | |
| Cache-Status | — | permanent | |
| Warning | — | obsoleted |
All categories
Authentication Authorization & Scope Caching Conditional Requests & Concurrency Content Negotiation Representation Metadata Connection & Transport CORS Security Policy Privacy & Consent Rate Limiting & Quota Tracing & Correlation Idempotency & Reliability Versioning & Lifecycle Integrity & Signing Async & Long-Running Cost & Metering Agent & Bot Identity