List of the most important HTTP status codes and what the mean
These are standard response codes given by website servers on the Internet. These codes can be used to identify why a web page is not loading properly. The most common and important codes are given below
HTTP Status Code - 200 OK
(in this case you will just see the requested page) This message signifies a successful request. The returned responses information depends on what method was used to send the request in the first place.
HTTP Status Code - 301 Moved Permanently
This error message means that a new permanent URI was assigned to the requested resource. So, one of the returned URIs must be used for future references to the resource.
HTTP Status Code - 302 Found
This message means that a different URI is the ‘temporary residence’
of the requested resource. The request-URI must be used by the client for future requests, since the redirection may only be changed on occasion.
HTTP Status Code - 304 Not Modified
The server will respond with this status code if there have been no modifications to the document and the client performed a conditional GET request, which allows access. There should not be a message body in the 304 response, so it ends at the first empty line following the fields in the header.
HTTP Status Code - 307 Temporary Redirect
This message means that a different URI is the ‘temporary residence’ of the requested resource. The request-URI must be used by the client for future requests, since the redirection may only be changed on occasion. If this response is marked by the Expires header field or the Cache-Control, then it is cacheable.
HTTP Status Code - 400 Bad Request
This means that because of the malformed syntax, the server could not understand the request. Until modifications are made, it is better that the client does not repeat the request.
HTTP Status Code - 401 Unauthorized
This means that user authentication is required for this request. A WWW-Authenticate header field MUST be included in the request, which contains a challenge that can be applied to the resource requested.
HTTP Status Code - 403 Forbidden
This message means that the server refuses to fulfill the request, even though it understood it. The client should not repeat the request and authorization will not help.
HTTP Status Code - 404 Not Found
This means that nothing that matched the request-URI was found by the server. It does not say if it is a permanent or temporary condition.
HTTP Status Code - 410 Gone
This message means exactly that – the requested resource is gone and is not available any more. There is no known forwarding address, and it is considered to be permanent. After user approval, clients who have capabilities to edit links must delete all references to this request-URI. If the server is unable to determine whether this is a permanent condition, then the 404 Not Found message must appear instead. This is a cacheable response, unless otherwise stated.
HTTP Status Code - 500 Internal Server Error
This means that there was an unexpected condition encountered by the server, and it was unable to fulfill the request.
HTTP Status Code - 501 Not Implemented
This means that the server was unable to fulfill the request, because it does not support the functionality required for it. This response is typical when the server is incapable of supporting the request or does not recognize its method.