Content negotiation
05The caller can express preferences for media type, language, or coding; the server chooses a representation.
Related RFCs and changes
“Updates” changes part of an earlier RFC. “Obsoletes” replaces it. This list shows selected related documents.
DIAGRAM§ 12 ↗
RFC 9110 · § 12EXAMPLE
4 / 4
04
Return the chosen representation.
The response metadata describes what actually arrived.
Protocol participantThreat or exceptionProtocol controlSimplified drawings · precise section references
RFC 7231 §5.3.3RFC 9110 §12.5.2
Accept-Charset is now deprecated. Appendix B.3 lists this change; senders should not use it as a modern charset-negotiation mechanism.
Read the updated RFC section ↗Negotiate a representation and describe the choice.
- Accept, Accept-Language, and Accept-Encoding express client preferences; q values express relative weights.
- Proactive negotiation selects before the response; reactive negotiation offers choices for a later request.
- Vary identifies request fields that influenced selection so caches can distinguish variants.
Preferences do not guarantee a particular result. The server can sometimes disregard them or return a negotiation failure. Accept-Charset is deprecated.
Read the RFC section ↗Diagrams simplify the RFC. Read the linked sections for complete requirements.
Privacy