406 Not Acceptable

4×× Client Error
406 Not Acceptable

The target resource does not have a current representation that would be acceptable to the user agent, according to the proactive negotiation header fields received in the request1, and the server is unwilling to supply a default representation.

The server SHOULD generate a payload containing a list of available representation characteristics and corresponding resource identifiers from which the user or user agent can choose the one most appropriate. A user agent MAY automatically select the most appropriate choice from that list. However, this specification does not define any standard for such automatic selection, as described in RFC7231 Section 6.4.1.

1 Content Negotiation RFC7231 Section 5.3
Source: RFC7231 Section 6.5.6

406 Code References

Rails HTTP Status Symbol :not_acceptable

Go HTTP Status Constant http.StatusNotAcceptable

Symfony HTTP Status Constant Response::HTTP_NOT_ACCEPTABLE

Python2 HTTP Status Constant httplib.NOT_ACCEPTABLE

Python3+ HTTP Status Constant http.client.NOT_ACCEPTABLE

Python3.5+ HTTP Status Constant http.HTTPStatus.NOT_ACCEPTABLE