From: Subject: HTTP Response Codes Date: Wed, 27 Nov 2002 20:09:26 +0100 MIME-Version: 1.0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Location: http://libraries.ucsd.edu/about/tools/http-response-codes.html X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 HTTP Response Codes

HTTP Response Codes

Below is a summary of what the HTTP Response Codes mean. For more = in-depth=20 information, see section = 10 of RFC=20 2616 (which defines what the reponse codes mean).=20

Authors should pay special attention to 400s and 500s, since these = mean that=20 the user did not successfully get to the page. 300s mean that the user = was=20 redirected, so the link might be changing. 600s generally mean that = there was a=20 problem with the URL, so the Link Checker couldn't figure out how to = check it.=20

1xx: Informational

These reponse codes indicate a provisional response that should = be=20 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=20 protocols.

2xx Successful

These reponse codes indicate that the client's request was = successfully=20 received, understood, and accepted.

200 OK The request has succeeded.
201 Created The request has been fulfilled and resulted in a = new=20 resource being created.
202 Accepted The request has been accepted for processing, but = the=20 processing has not been completed.
203 Non-Authoritative Information The returned headers are not definitive, but are = gathered=20 from a local or a third-party copy.
204 No Content The server has fulfilled the request but does not = need to=20 return any output.
205 Reset Content The server has fulfilled the request and the client = should=20 reset the document view (primarily intended to make data-entry=20 easier).
206 Partial Content The server has fulfilled the partial GET request = for the=20 resource.

3xx: Redirection

These response codes indicate that the client was redirected to = another=20 URI, or that further action needs to be taken by the user agent in = order=20 to fulfill the request.

300 Multiple Choices There are several resources that match this = request, and=20 the client was redirected to one of them.
301 Moved Permanently The requested resource has been assigned a new = permanent=20 URI and any future references to this resource should use the new=20 URI.
302 Found The requested resource resides temporarily under a=20 different URI. Since the redirection might be altered, continue to = use the=20 old URI.
303 See Other The response to the request can be found under a = different=20 URI and should be retrieved from the new URI.
304 Not Modified The document has not been modified since the last = request,=20 and the locally cached copy should be used instead.
305 Use Proxy The requested resource must be accessed through a=20 proxy.
306 (Unused) Used in a previous version of the = protocol.
307 Temporary Redirect The requested resource resides temporarily under a=20 different URI. Since the redirection may be altered on occasion, = continue=20 to use the current URI.

4xx: Client Errors

These response codes are intended for cases in which the client = seems=20 to have erred.

400 Bad Request The request could not be understood by the server = due to=20 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=20 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=20 execute a normal document or display a script.
406 Not Acceptable According to the client's request, it isn't capable = of=20 handling the response.
407 Proxy Authentication Required This code is similar to 401 (Unauthorized), but = indicates=20 that the client must first authenticate itself with the = proxy.
408 Request Timeout The client did not produce a request within the = time that=20 the server was prepared to wait.
409 Conflict The request could not be completed due to a = conflict with=20 the current state of the resource. Typically only seen with = clients that=20 can manage files on the remote server.
410 Gone The requested resource is no longer available at = the server=20 and no forwarding address is known.
411 Length Required The server refuses to accept the request without a = defined=20 Content-Length header.
412 Precondition Failed The precondition given in one or more of the header = fields=20 failed when it was tested on the server.
413 Request Entity Too Large The server is refusing to process a request because = the=20 request entity is larger than the server is willing or able to=20 process.
414 Request-URI Too Long The server is refusing to service the request = because the=20 requested URI is too long.
415 Unsupported Media Type The server is refusing to service the request = because the=20 client does not support the response format.
416 Requested Range Not Satisfiable The server could not find the range specified in = the Range=20 header.
417 Expectation Failed The server could not meet the expectation given in = the=20 Expect header.

5xx: Server Errors

These response codes indicate cases in which the server is = aware that=20 it has erred or is incapable of performing the = request.

500 Internal Server Error The server encountered an unexpected condition = which=20 prevented it from fulfilling the request.
501 Not Implemented The server does not support the functionality = required to=20 fulfill the request.
502 Bad Gateway The server is a gateway or proxy and received an = invalid=20 response from the upstream server it accessed in attempting to = fulfill the=20 request.
503 Service Unavailable The server is currently unable to handle the = request due to=20 a temporary overloading or maintenance of the server.
504 Gateway Timeout The server is a gateway or proxy and did not = receive a=20 timely response from the upstream server.
505 HTTP Version Not Supported The server does not support, or refuses to support, = the=20 HTTP protocol version that was used in the request.

6xx: Internal Errors

These response codes indicate that an error occurred in the = link=20 checking program itself (these are unofficial error codes used to = report=20 problems).

600 Malformed URI The link checking program was not able to parse the = URI.=20 This means that the URI was either empty, or not a valid URI (e.g. = "Ask at=20 S&E Reference Desk").
601 Connection Timed Out The server did not respond before the connection = timed=20 out.
602 Unknown Error Some other error occurred in contacting the server, = making=20 the request, or parsing the response. This could be due to a = mangled or=20 incorrectly formatted response from the server.
603 Could Not Parse Reply The reply from the server could not be parsed. This = could=20 indicate a malformed response, or a non-numerical response = code.
604 Protocol Not Supported This URI uses a protocol that is not currently = supported by=20 the linkchecker program. The linkchecker currently only supports = http, so=20 ftp, https, gopher, etc. are not supported. Also, some protocols = (such as=20 mailto://) cannot be = checked.