HTTP Response Codes

HTTP Response Codes

Below is a summary of what the HTTP Response Codes mean. For more in-depth information, see section 10 of RFC 2616.

Pay special attention to 400s and 500s, since these mean that the user did not successfully get to the page. 300s mean that the user was redirected, so the link might be changing.

1xx: Informational

These response codes indicate a provisional response that should be followed by another response.

100 Continue The server has not rejected the initial part of the request, and the client should continue.
101 Switching Protocols The server agrees with the client's request to change protocols.

2xx Successful

These response codes indicate that the client's request was successfully received, understood, and accepted.

200 OK The request has succeeded.
201 Created The request has been fulfilled and resulted in a new resource being created.
202 Accepted The request has been accepted for processing, but the processing has not been completed.
203 Non-Authoritative Information The returned headers are not definitive, but are gathered from a local or a third-party copy.
204 No Content The server has fulfilled the request but does not need to return any output.
205 Reset Content The server has fulfilled the request and the client should reset the document view (primarily intended to make data-entry easier).
206 Partial Content The server has fulfilled the partial GET request for the resource.

3xx: Redirection

These response codes indicate that the client was redirected to another URI, or that further action needs to be taken by the user agent in order to fulfill the request.

300 Multiple Choices There are several resources that match this request, and the client was redirected to one of them.
301 Moved Permanently The requested resource has been assigned a new permanent URI and any future references to this resource should use the new URI.
302 Found The requested resource resides temporarily under a different URI. Since the redirection might be altered, continue to use the old URI.
303 See Other The response to the request can be found under a different URI and should be retrieved from the new URI.
304 Not Modified The document has not been modified since the last request, and the locally cached copy should be used instead.
305 Use Proxy The requested resource must be accessed through a proxy.
306 (Unused) Used in a previous version of the protocol.
307 Temporary Redirect The requested resource resides temporarily under a different URI. Since the redirection may be altered on occasion, continue to use the current URI.

4xx: Client Errors

These response codes are intended for cases in which the client seems to have erred.

400 Bad Request The request could not be understood by the server due to malformed syntax.
401 Unauthorized The request requires user authentication.
402 Payment Required This code is reserved for future use.
403 Forbidden The server understood the request, but is refusing to fulfill it. Typically due to file access permissions on the server.
404 Not Found The server has not found anything matching the URI.
405 Method Not Allowed The request method is not allowed. Typically when trying to execute a normal document or display a script.
406 Not Acceptable According to the client's request, it isn't capable of handling the response.
407 Proxy Authentication Required This code is similar to 401 (Unauthorized), but indicates that the client must first authenticate itself with the proxy.
408 Request Timeout The client did not produce a request within the time that the server was prepared to wait.
409 Conflict The request could not be completed due to a conflict with the current state of the resource. Typically only seen with clients that can manage files on the remote server.
410 Gone The requested resource is no longer available at the server and no forwarding address is known.
411 Length Required The server refuses to accept the request without a defined Content-Length header.
412 Precondition Failed The precondition given in one or more of the header fields failed when it was tested on the server.
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.
414 Request-URI Too Long The server is refusing to service the request because the requested URI is too long.
415 Unsupported Media Type The server is refusing to service the request because the client does not support the response format.
41416 Requested Range Not Satisfable The server could not find the range specified in the Range header.
417 Expectation Failed The server could not meet the expectation given in the Expect header.

5xx: Server Errors

These response codes indicate cases in which the server is aware that it has erred or is incapable of performing the request.

500 Internal Server Error The server encountered an unexpected condition which prevented it from fulfilling the request.
501 Not Implemented The server does not support the functionality required to fulfill the request.
502 Bad Gateway The server is a gateway or proxy and received an invalid response from the upstream server it accessed in attempting to fulfill the request.
503 Service Unavailable The server is currently unable to handle the request due to a temporary overloading or maintenance of the server.
504 Gateway Timeout The server is a gateway or proxy and did not receive a timely response from the upstream server.
505 HTTP Version Not Supported The server does not support, or refuses to support, the HTTP protocol version that was used in the request.