406 Not Acceptable

The HTTP 406 Not Acceptable client error response status code indicates that the server could not produce a response matching the list of acceptable values defined in the request's proactive content negotiation headers and that the server was unwilling to supply a default representation.

Proactive content negotiation headers include:

• Accept
• Accept-Encoding
• Accept-Language

A server may return responses that differ from the request's accept headers. In such cases, a 200 response with a default resource that doesn't match the client's list of acceptable content negotiation values may be preferable to sending a 406 response.

If a server returns a 406, the body of the message should contain the list of available representations for the resource, allowing the user to choose, although no standard way for this is defined.

406 Not Acceptable

GET /docs/doc1 HTTP/1.1
Host: example.com
Accept: application/rtf;

HTTP/1.1 406 Not Acceptable
Date: Wed, 26 Jun 2024 12:00:00 GMT
Server: Apache/2.4.1 (Unix)
Content-Type: application/json

{
  "code": "UnsupportedType",
  "message": "Only 'text/html' or 'application/json' content types supported.",
}