414 URI Too Long means the request target, the URL path plus query, is longer than the server is willing to interpret. RFC 9110 recommends that servers support URLs of at least 8,000 octets, but many servers, proxies and CDNs have lower limits.
414 is rare in normal browsing. It usually appears when a form that should use POST sends large amounts of data with GET, when tracking or state parameters pile up in a URL, or when a redirect loop adds something to the URL on every hop until it is too long. A 414 is heuristically cacheable.
Example response
HTTP/1.1 414 URI Too Long
Date: Fri, 06 Nov 2026 10:15:32 GMT
Content-Type: text/html
Content-Length: 51
Connection: close
<html><body><h1>414 URI Too Long</h1></body></html>SEO and redirect checking
Search engines cannot index URLs that return 414, and URLs that long are rarely meant to be indexed anyway. A 414 at the end of a redirect chain strongly suggests a loop that grows the URL each time; the Redirect Loop Checker shows how the URL changes from hop to hop.
Common causes and use cases
- A redirect loop appends a parameter such as
?redirect=or&lang=on every pass. - A search or filter form sends many parameters with
GET. Switch toPOSTor shorten the state kept in the URL. - Several redirectors in a row each append their own tracking parameters.
- A server's URL length limit is set very low, for example by
large_client_header_buffersin nginx orLimitRequestLinein Apache.