---
set: 5
code: 505
title: HTTP Version Not Supported
references:
    "Rails HTTP Status Symbol": ":http_version_not_supported"
    "Go HTTP Status Constant": "http.StatusHTTPVersionNotSupported"
    "Symfony HTTP Status Constant": "Response::HTTP_VERSION_NOT_SUPPORTED"
    "Python2 HTTP Status Constant": "httplib.VERSION_NOT_SUPPORTED"
    "Python3+ HTTP Status Constant": "http.client.VERSION_NOT_SUPPORTED"
    "Python3.5+ HTTP Status Constant": "http.HTTPStatus.VERSION_NOT_SUPPORTED"
---

The server does not support, or refuses to support, the major version of HTTP that was used in the request message.

The server is indicating that it is unable or unwilling to complete the request using the same major version as the client, as described in [Section 2.6 of RFC7230][2], other than with this error message. The server SHOULD generate a representation for the 505 response that describes why that version is not supported and what other protocols are supported by that server.

---

* Source: [RFC7231 Section 6.6.6][1]

[1]: <http://tools.ietf.org/html/rfc7231#section-6.6.6>
[2]: <http://tools.ietf.org/html/rfc7230#section-2.6>