HTTP Messages
HTTP Status Messages
HTML Error Messages
When a browser requests a service from a web server, an error might occur, and the server might return an error code like "404 Not Found".
It is common to name these errors HTML error messages.
But these messages are something called HTTP status messages. In fact, the server always returns a message for every request. The most common message is 200 OK.
Below is a list of HTTP status messages that might be returned:
1xx: Information
Message:Description:100 ContinueThe server has received the request headers, and the client should proceed to send the request body101 Switching ProtocolsThe requester has asked the server to switch protocols103 CheckpointUsed in the resumable requests proposal to resume aborted PUT or POST requests
2xx: Successful
Message:Description:200 OKThe request is OK (this is the standard response for successful HTTP requests)201 CreatedThe request has been fulfilled, and a new resource is created 202 AcceptedThe request has been accepted for processing, but the processing has not been completed203 Non-Authoritative InformationThe request has been successfully processed, but is returning information that may be from another source204 No ContentThe request has been successfully processed, but is not returning any content205 Reset ContentThe request has been successfully processed, but is not returning any content, and requires that the requester reset the document view206 Partial ContentThe server is delivering only part of the resource due to a range header sent by the client
3xx: Redirection
Message:Description:300 Multiple ChoicesA link list. The user can select a link and go to that location. Maximum five addresses 301 Moved PermanentlyThe requested page has moved to a new URL 302 FoundThe requested page has moved temporarily to a new URL 303 See OtherThe requested page can be found under a different URL304 Not ModifiedIndicates the requested page has not been modified since last requested306 Switch ProxyNo longer used307 Temporary RedirectThe requested page has moved temporarily to a new URL308 Resume IncompleteUsed in the resumable requests proposal to resume aborted PUT or POST requests
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4xx: Client Error
Message:Description:400 Bad RequestThe request cannot be fulfilled due to bad syntax401 UnauthorizedThe request was a legal request, but the server is refusing to respond to it. For use when authentication is possible but has failed or not yet been provided402 Payment RequiredReserved for future use403 ForbiddenThe request was a legal request, but the server is refusing to respond to it404 Not FoundThe requested page could not be found but may be available again in the future405 Method Not AllowedA request was made of a page using a request method not supported by that page406 Not AcceptableThe server can only generate a response that is not accepted by the client407 Proxy Authentication RequiredThe client must first authenticate itself with the proxy408 Request TimeoutThe server timed out waiting for the request409 ConflictThe request could not be completed because of a conflict in the request410 GoneThe requested page is no longer available411 Length RequiredThe "Content-Length" is not defined. The server will not accept the request without it 412 Precondition FailedThe precondition given in the request evaluated to false by the server413 Request Entity Too LargeThe server will not accept the request, because the request entity is too large414 Request-URI Too LongThe 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 TypeThe server will not accept the request, because the media type is not supported 416 Requested Range Not SatisfiableThe client has asked for a portion of the file, but the server cannot supply that portion417 Expectation FailedThe server cannot meet the requirements of the Expect request-header field
5xx: Server Error
Message:Description:500 Internal Server ErrorA generic error message, given when no more specific message is suitable501 Not ImplementedThe server either does not recognize the request method, or it lacks the ability to fulfill the request502 Bad GatewayThe server was acting as a gateway or proxy and received an invalid response from the upstream server503 Service UnavailableThe server is currently unavailable (overloaded or down)504 Gateway TimeoutThe server was acting as a gateway or proxy and did not receive a timely response from the upstream server505 HTTP Version Not SupportedThe server does not support the HTTP protocol version used in the request511 Network Authentication RequiredThe client needs to authenticate to gain network access