HTTP Status Codes

HTTP Status Code Reference Guide

• 501 Not Implemented (HTTP Status Code 501)

  The HTTP 501 error, meaning "Not Implemented," is a server error status code indicating that the server does not support the functionality required to fulfill the request.

• 502 Bad Gateway (HTTP Status Code 502)

  Status code 502 Bad Gateway is an HTTP error response code indicating that a server acting as a gateway or proxy received an invalid response from an upstream server.

• 503 Service Unavailable (HTTP Status Code 503)

  The HTTP 503 status code indicates that the server is temporarily unable to handle the request.

• 504 Gateway Timeout (HTTP Status Code 504)

  The HTTP 504 (Gateway Timeout) status code indicates that a server acting as a gateway or proxy timed out while waiting for a response from an upstream server.

• 505 HTTP Version Not Supported (HTTP Status Code 505)

  The HTTP 505 (HTTP Version Not Supported) status code indicates that the server does not support the HTTP protocol version used in the request.

• 506 Variant Also Negotiates (HTTP Status Code 506)

  HTTP 506 is a relatively uncommon status code indicating an internal server configuration error.