| 1xx | Informational | 100 | Continue
| The client should continue with its request. ref. |
| | 101 | Switching Protocols | The client should switch to the protocol requested in the Upgrade message header field. ref. |
| | | | |
| 2xx | Successful | 200 | OK | The request has succeeded. ref. |
| | 201 | Created | The request has been fulfilled and resulted in a new resource being created. ref. |
| | 202 | Accepted | The request has been accepted for processing, but the processing has not yet completed. ref. |
| | 203 | Non-authoritative information | The returned information in the entity-header is not the definitive set as available from the origin server, but is gathered from an unknown third party. ref. |
| | 204 | No content | The server has fulfilled the request, but has nothing to return. ref. |
| | 205 | Reset content | The server has fulfilled the request and the user agent should reset the document view which caused the request to be sent. ref. |
| | 206 | Partial content | The server has fulfilled the partial GET request. ref. |
| | | | |
| 3xx | Redirection | 300 | Multiple choices. | The requests corresponds to any one of a number of representations, each with its own specific location. The user can select a preferred representation.ref. |
| | 301 | Moved permanently | The requested resourced has been assigned a new permanent URI and any future requests should use this URI. ref. |
| | 302 | Found | The requested resource resides temporarily under a different URI. The client should continue to use the original request URI for future requests. ref. |
| | 303 | See other | The response to the request can be found under a different URI and should be retrieved using a GET method on that resource. ref. |
| | 304 | Not modified | If the client has performed a conditional GET, but the document has not been modified, a 304 will be returned. ref. |
| | 305 | Use proxy | The requested resource must be accessed through the proxy given in the location field. ref. |
| | 307 | Temporary redirect | The requested resource resides temporarily under a different URI. The client shoudl continue to use the original request URI for future requests. ref. |
| | | | |
| 4xx | Client Error | 400 | Bad Request | The request could not be understood by the server due to malformed syntax. ref. |
| | 401 | Unauthorized | The request requires user authentication. ref. |
| | 402 | Payment required | This code is reserved for future use. ref. |
| | 403 | Forbidden | The server understood the request, but is refusing to fulfill it. ref. |
| | 404 | Not found | The server could not find anything matching the request URI. ref. |
| | 405 | Method not allowed | The method specified in the request line is not allowed for the resource identified by the request URI. The response will include an Allow header containing a list of valid methods for the requested resource. ref. |
| | 406 | Not acceptable | The resource identified by the request will return a response that is incompatible with the request headers.ref. |
| | 407 | Proxy authentication required | This code is similar to 401 (Unauthorized), but indicates that the client must first authenticate itself with the proxy. ref. |
| | 408 | Request timeout | The client did not produce a request within the time that the server was willing to wait. ref. |
| | 409 | Conflict | The request could not be completed due to a conflict with the current state of the resource. ref. |
| | 410 | Gone | The requested resource is no longer available at the server and no forwarding address is known. ref. |
| | 411 | Length required | The server refuses to accept the request without a defined Content-Length. ref. |
| | 412 | Precondition failed | The precondition given in one or more of the request-header fields evaluated to false when it was tested on the server. ref. |
| | 413 | Request entity too large | The server is refusing to process a request because the request entity is larger than the server is willing or able to process. ref. |
| | 414 | Request uri too long | The server is refusing to service the request becuase the request URI is longer than the server is willing to accept. ref. |
| | 415 | Unsupported media type | The server is refusing to service the request becuase the entity of the request is in a format not supported by the requested resource for the requested method. ref. |
| | 416 | Request range not satisfiable | The requested included a Range request-header field, and none of the range-specifier field values in this field overlap the current extend of the selected resource. ref. |
| | 417 | Expectation failed | The expectation given in an Expect request-header field could not be met by this server. ref. |
| | | | |
| 5xx | Server Error | 500 | Internal server error | The server encountered an unexpected condition which prevented it from fulfilling the request. ref. |
| | 501 | Not implemented | The server does not support the functionality required to fulfill the request. ref. |
| | 502 | Bad gateway | The server, while acting as a proxy or gateway, received an invalid response from the upstream server it accessed in an attempt to fulfill the request. ref. |
| | 503 | Service unavailable | The server is currently unable to handle the request due to a temporary overloading or maintenance of the server. ref. |
| | 504 | Gateway timeout | The server, while acting as a proxy or a gateway, did not receive a response from the upstream server specified by the request URI. ref. |
| | 505 | HTTP version not supported | The server does not support, or refuses to support, the HTTP protocol version that was used in the request message. ref. |