`Vary`

Request headers that change the response.

Response header (sent by servers) caching

How it works

Caches store separate copies per value. Responses that differ by Authorization or Origin must say so, or a cache may serve one user’s data to another.

Example

Vary: Origin, Accept-Encoding

See it live: send any request in Endpoint Client and open the Headers tab, where every response header is explained. Specification: RFC 9110.

Related headers

`Age`

Seconds the response has spent in a shared cache.

`Cache-Control`

Caching rules for browsers, proxies and CDNs.

`Expires`

Absolute time after which the response is stale.