414 URI Too Long
This is an educational reference page about HTTP 414 URI Too Long. The page itself is served as 200 OK so it can be indexed as HTTP documentation.
The URI provided was too long for the server to process. Often the result of too much data being encoded as a query-string of a GET request, in which case it should be converted to a POST request. Called "Request-URI Too Long" previously.
Specification
Registered in the IANA HTTP Status Code Registry as URI Too Long. Defined in RFC 9110, Section 15.5.15.
Header and content rules
RFC 9110 adds no header or content rule specific to 414. The 4xx class rules also apply. See 414 in the response obligations table.