---
set: 4
code: 406
title: Not Acceptable
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"
---

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 request<sup>[1](#ref-1)</sup>, 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][3].

---

* <span id="ref-1"><sup>1</sup> Content Negotiation
[RFC7231 Section 5.3][2]</span>
* Source: [RFC7231 Section 6.5.6][1]

[1]: <http://tools.ietf.org/html/rfc7231#section-6.5.6>
[2]: <http://tools.ietf.org/html/rfc7231#section-5.3>
[3]: <http://tools.ietf.org/html/rfc7231#section-6.4.1>