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Expires

IANA permanent response RFC 9111 2 spellings

Declared by 20 providers across 1413 published specification files in the APIs.io network.

What this header is for, and how to use it →

A count here is providers whose published contract declares this header — not providers who send it. Response headers set at the edge rarely appear in an OpenAPI at all, so a low number can measure documentation practice rather than deployment.

Spelled 2 ways

HTTP field names are case-insensitive (RFC 9110 §5.1), so every spelling below is the same header on the wire. A contract is not the wire: generated clients key off the string, and a developer reading two of these sees two different headers.

Expiresexpires

The registry

Statuspermanent
ReferenceRFC 9111, Section 5.3: HTTP Caching

Providers declaring it (20)

amazon-s3 aws-s3 bird chili-piper constructorio deliverect engineering-platform eve-online extreme-networks hopper-com oracle roadsync salesforce sp-global spectro-cloud upwind upwind-security vtex wikimedia wikipedia

Explore

All headers Caching Guidance on headers.apievangelist.com