431 Request Header Fields Too Large

Document v1 · published by Koskamo · updated 2026-10-04

HTTP 431 Request Header Fields Too Large is a 4xx client error status code in the IANA HTTP Status Code Registry.

Code: 431
Reason phrase: Request Header Fields Too Large
Class: 4xx (Client Error)
Defined in: RFC 6585

Source and provenance

Original source: www.iana.org
Published on Koskamo by: Koskamo
Citation version: Document v1
Reuse: IANA HTTP Status Code Registry (iana.org/assignments/http-status-codes); registry data reproduced verbatim with references

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Version history

Published by Koskamo2026-10-04
Version 1