RFC 8942

HTTP Client Hints, February 2021

File formats:

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Status:
EXPERIMENTAL
Authors:
I. Grigorik
Y. Weiss
Stream:
IETF
Source:
httpbis (art)

Cite this RFC: TXT  |  XML

DOI:  10.17487/RFC8942

Discuss this RFC: Send questions or comments to ietf-http-wg@w3.org

Other actions: Submit Errata  |  Find IPR Disclosures from the IETF


Abstract

HTTP defines proactive content negotiation to allow servers to select the appropriate response for a given request, based upon the user agent's characteristics, as expressed in request headers. In practice, user agents are often unwilling to send those request headers, because it is not clear whether they will be used, and sending them impacts both performance and privacy.

This document defines an Accept-CH response header that servers can use to advertise their use of request headers for proactive content negotiation, along with a set of guidelines for the creation of such headers, colloquially known as "Client Hints."


For the definition of Status, see RFC 2026.

For the definition of Stream, see RFC 8729.