Http response codes

Answer by: Stuart Pierce, Aplus.Net Knowledge Base Support

Here is a list of the standard HTTP response codes of the Apache Server:

I. Successful Client Requests

200 – OK: the request was received successfully and is being processed.
201 – Created: the request was successful and as a result, a resource has been created (for example a new page).
202 – Accepted: the server has received and understood the request, and that it has been accepted for processing, although it may not be processed immediately.
203 – Non-Authoritative Information: the request was received, although the information sent back is from a third party, rather than the original server. Identical to 200 response code.
204 - No Content: the request was received and understood, but that there is no need to send any data back.
205 - Reset Content: request from the server to the client to reset the document from which the original request was sent.
206 - Partial Content: response to a request for part of a document.

II. Client Requests Redirected

300 – Multiple Choices: a resource has been moved. The response will also include a list of locations from which the user agent can select the most appropriate.
301 – Moved Permanently: the resource has been permanently moved to a new location. The response should also include this location.
302 – Moved Temporarily: the resource has been temporarily moved to a new location. The response should also include this location.
303 – See Other: the response to the request can be found at the specified URL, and should be retrieved from there.
304 – Not Modified: response to a request (for a document) that asked for the document only if it was newer than the one the client already had.
305 – Use Proxy: the requested resource has to be reached through a proxy, which will be specified in the response.

III. Client Request Errors

400 – Bad Request: the server did not understand the request due to bad syntax.
401 – Unauthorized: before a resource can be accessed, the client must be authorized by the server.
402 – Payment Required: not currently in use, being listed as "reserved for future use".
403 – Forbidden: client cannot access the requested resource.
404 – Not Found: the requested resource was not found at the given URL.
405 – Method Not Allowed: the client has tried to use a request method that the server does not allow.
406 – Not Acceptable: although the server understood and processed the request, the response is of a form the client cannot understand. A client sends, as part of a request, headers indicating what types of data it can use, and a 406 error is returned when the response is of a type not in that list.
407 – Proxy Authentication Required: the client must be authorized by the proxy before the request can proceed.
408 – Request Timeout: client did not produce a request quickly enough.
409 – Conflict: the server was unable to complete the request, often because a file would need to be edited, and that is not possible at the moment.
410 – Gone: the resource has permanently gone. Differs from 404 because 404 does not specify whether the resource has gone permanently or temporarily.
411 – Length Required: the server refuses to process a request because a content length was not specified.
412 – Precondition Failed: one of the conditions the request was made under has failed.
413 – Request Entity Too Large: the request was larger than the server is able to handle, either due to physical constraints or to settings.
414 – Request URL Too Long: the URL requested by the client was longer than it can process.
415 – Unsupported Media Type: part of the request was in an unsupported format.

IV. Server Errors

500 – Internal Server Error: the server encountered something it didn't expect and was unable to complete the request. Could be caused by a number of reasons.
501 – Not Implemented: the server does not support all that is needed for the request to be completed.
502 – Bad Gateway: the server, while acting as a proxy, received a response from another server that it considered invalid.
503 – Service Unavailable: the server was unable to complete the request due to a server overload.
504 – Gateway Timeout: the server acting as a proxy has waited too long for a response from a server further upstream.
505 – HTTP Version Not Supported: the HTTP version indicated in the request is no supported. The response should indicate which HTTP versions are supported.