HTTP Status Codes

 

2XX responses:     The 2xx (Successful) class of status code indicates that the client's request was successfully received, understood, and accepted
4XX Errors:     The 4xx (Client Error) class of status code indicates that the client seems to have erred
  400 Bad Request The 400 (Bad Request) status code indicates that the server cannot or will not process the request due to something that is perceived to be a client error
  401 Unauthorized The 401 Unauthorized Error is an HTTP response status code indicating that the request sent by the client could not be authenticated
  403 Forbidden The 403 (Forbidden) status code indicates that the server understood the request but refuses to authorize it
  404 Page or Resource Not Found The 404 (Not Found) status code indicates that the origin server did not find a current representation for the target resource
  405 Method Not Allowed The 405 (Method Not Allowed) status code indicates that the method received is not supported by the target resource
  429 Too Many Requests The HTTP 429 status code indicates the user has sent too many requests in a given amount of time ("rate limiting")
5XX Errors:     The 5xx (Server Error) class of status code indicates that the server is aware that it has erred or is incapable of performing the requested method
  500 Internal Server Error The 500 (Internal Server Error) status code indicates that the server encountered an unexpected condition that prevented it from fulfilling the request
  502 Bad Gateway The 502 (Bad Gateway) status code indicates that the server, while acting as a gateway or proxy, received an invalid response from an inbound server it accessed
  503 Service Unavailable The 503 (Service Unavailable) status code indicates that the server is currently unable to handle the request
  504 Gateway Timeout The 504 (Gateway Timeout) status code indicates that the server, while acting as a gateway or proxy, did not receive a timely response from an upstream server