414 URI Too Long

The URL (request target) is longer than the server is willing to interpret.

414 at a glance

Code: 414
Name: URI Too Long
Class: 4xx Client error
Status: IANA-registered standard code
Defined in: RFC 9110, Section 15.5.15
Cacheable by default: Yes, heuristically cacheable (RFC 9110 section 15.1): without Cache-Control or Expires, caches may store it and pick a freshness lifetime themselves. Send explicit Cache-Control to stay in control.

What 414 means

414 URI Too Long means the request line is over the server's limit. Usually this is a GET carrying far too much data in the query string, or a redirect loop that keeps appending parameters. 414 is heuristically cacheable.

What typically causes a 414

nginx large_client_header_buffers (default 4 x 8k) limits the request line.
Apache LimitRequestLine (8190 bytes by default).
Forms submitted with GET carrying large text, or tracking redirects appending the same parameter repeatedly.
Search or filter UIs that encode huge state in the URL.

Fix it on the server

Raise the buffer limit only if long URLs are legitimate; otherwise fix the client to POST the data.

Fix it as a client or visitor

Send large inputs in a POST body instead of the query string.
If a redirect chain keeps growing the URL, there is a loop: inspect it with curl -sIL.

Example response

HTTP/1.1 414 Request-URI Too Large
Server: nginx
Content-Type: text/html