1xx: Informational - It means the request has been received and the process is continuing.
2xx: Success - It means the action was successfully received, understood, and accepted.
3xx: Redirection - It means further action must be taken in order to complete the request.
4xx: Client Error - It means the request contains incorrect syntax or cannot be fulfilled.
5xx: Server Error - It means the server failed to fulfill an apparently valid request.
100 Continue - Only a part of the request has been received by the server, as long as it has not been rejected, the client should continue with the request.
101 Switching Protocols - The server switches protocol.
200 OK - The request is OK.
201 Created - The request is complete, and a new resource is created .
202 Accepted - The request is accepted for processing, but the processing is not complete.
203 Non-authoritative Information - The information in the entity header is from a local or third-party copy, not from the original server.
204 No Content - A status code and a header are given in the response, but there is no entity-body in the reply.
205 Reset Content - The browser should clear the form used for this transaction for additional input.
206 Partial Content - The server is returning partial data of the size requested. Used in response to a request specifying a Range header. The server must specify the range included in the response with the Content-Range header.
300 Multiple Choices - A link list. The user can select a link and go to that location. Maximum five addresses.
301 Moved Permanently - The requested page has moved to a new url .
302 Found - The requested page has moved temporarily to a new url .
303 See Other - The requested page can be found under a different url .
304 Not Modified - This is the response code to an If-Modified-Since or If-None-Match header, where the URL has not been modified since the specified date.
305 Use Proxy - The requested URL must be accessed through the proxy mentioned in the Location header.
306 Unused - This code was used in a previous version. It is no longer used, but the code is reserved.
307 Temporary Redirect - The requested page has moved temporarily to a new url.
400 Bad Request - The server did not understand the request.
401 Unauthorized - The requested page needs a username and a password.
402 Payment Required - You can not use this code yet.
403 Forbidden - Access is forbidden to the requested page.
404 Not Found - The server can not find the requested page.
405 Method Not Allowed - The method specified in the request is not allowed.
406 Not Acceptable - The server can only generate a response that is not accepted by the client.
407 Proxy Authentication Required - You must authenticate with a proxy server before this request can be served.
408 Request Timeout - The request took longer than the server was prepared to wait.
409 Conflict - The request could not be completed because of a conflict.
410 Gone - The requested page is no longer available.
411 Length Required - The "Content-Length" is not defined. The server will not accept the request without it.
412 Precondition Failed - The pre condition given in the request evaluated to false by the server.
413 Request Entity Too Large - The server will not accept the request, because the request entity is too large.
414 Request-url Too Long - The server will not accept the request, because the url is too long. Occurs when you convert a "post" request to a "get" request with a long query information.
415 Unsupported Media Type - The server will not accept the request, because the mediatype is not supported .
416 Requested Range Not Satisfiable - The requested byte range is not available and is out of bounds.
417 Expectation Failed - The expectation given in an Expect request-header field could not be met by this server.
500 Internal Server Error - The request was not completed. The server met an unexpected condition.
501 Not Implemented - The request was not completed. The server did not support the functionality required.
502 Bad Gateway - The request was not completed. The server received an invalid response from the upstream server.
503 Service Unavailable - The request was not completed. The server is temporarily overloading or down.
504 Gateway Timeout - The gateway has timed out.
505 HTTP Version Not Supported - The server does not support the "http protocol" version.