414 URI Too Long

The HTTP 414 URI Too Long status code is a client error returned by the server to indicate the URI exceeds the length the server allows.

Usage

When the 414 URI Too Long error message is received, the client understands the server expects a smaller HTTP path or address. While the specification does not stipulate any requirement for length, in practice, browsers limit the size to prevent certain types of attacks.

For example, many web applications limit the size of the URL for an HTTP GET request to 2,048 characters. This is not necessarily a limit enforced by the server or browser.

The 414 URI Too Long response is cacheable by default.

Example

The client requests a resource using a URI beyond what the server allows.

Request

GET /<...a_long_URI...> HTTP/1.1
Host: www.example.re

Response

HTTP/1.1 414 URI Too Long

How to fix

The most common cause is a GET request with too many query parameters or excessively long values encoded in the URL. A redirect loop or misconfigured rewrite rule appending parameters on each cycle also triggers this error.

Client-side fixes:

• Shorten the URL by removing unnecessary query parameters
• Move large parameter sets to the request body using POST instead of GET
• Avoid encoding large data structures (JSON blobs, Base64 strings) in the query string
• Check for redirect loops adding parameters on each redirect cycle

nginx: Increase large_client_header_buffers to allow longer request lines. The directive takes two values: buffer count and buffer size, e.g. large_client_header_buffers 4 32k. Restart nginx to apply.

Apache: Set LimitRequestLine in httpd.conf to a higher byte value. The default is 8190 bytes. Values up to 128000 are common for applications with long URLs. Restart Apache after the change.

IIS: Edit maxUrl and maxQueryString in the web.config file under system.webServer > security > requestFiltering > requestLimits. The defaults are 4096 bytes for URL length and 2048 bytes for query strings. Keep these values as low as practical. Large URL limits increase exposure to injection attacks.

When the error appears in a browser rather than an API, clearing the browser cache and cookies sometimes resolves the issue, especially when stale cookies inflate the request header size beyond server limits.

Code references

.NET

HttpStatusCode.RequestUriTooLong

Rust

http::StatusCode::URI_TOO_LONG

Rails

:uri_too_long
:request_uri_too_long

Go

http.StatusRequestURITooLong

Symfony

Response::HTTP_REQUEST_URI_TOO_LONG

Python3.5+

http.HTTPStatus.REQUEST_URI_TOO_LONG

Java

java.net.HttpURLConnection.HTTP_REQ_TOO_LONG

Apache HttpComponents Core

org.apache.hc.core5.http.HttpStatus.SC_REQUEST_URI_TOO_LONG

Angular

@angular/common/http/HttpStatusCode.UriTooLong

Takeaway

The 414 URI Too Long status code is a client error indicating the URI is larger than the server is willing to accept.

See also

• RFC 9110: HTTP Semantics
• Google: HTTP status codes and network errors
• GET
• HTTP status codes
• HTTP headers