What are these Apache codes?
200 – OK
A 200 response code means the connection has been successful and the browser will serve the websites content.
206 – Partial Content
This code explains that the connection is only requesting parts of the website such as just the code with a wget command, this code can be fairly common.
301 – Moved Permanently
This code lets the browser know that the url has been moved permanately to a new location and to forward all future request to the new location.
302 – Moved Temporarily
This code is very similar to 301 but instead of a permanent move, it is temporary.
303 – See Other
This code is a way to redirect web applications to a new URL.
304 – Not Modified
This indicates that the browser has a cached copy of the website and the website has not had any modications since the browsers last visit.
400 – Bad Request
The server is not able to process the clients request due to something wrong with the client (e.g., malformed request syntax, invalid request message framing, or deceptive request routing).
401 – Unauthorized
Similar to 403 Forbidden, but specifically for when authentication is required to continue to the website.
403 – Forbidden
The request was valid, however the server is refusing the connection due to configuration settings.
404 – Not Found
The file requested resource could not be found but may be available again in the future. If your website is showing many 404 hits and you are using WordPress SuperCache then you should switch to WP Total Cache as this plugin will cache the 404 page to prevent additional account resources. You can read more on 404 errors here.
405 – Method Not Allowed
A request was made to the website which was different than it was programmed to handle such as using GET on a form which requires data to be presented via POST, or using PUT on a read-only resource.
406 – Not Acceptable
This code means that the server has blocked the request via mod_security. For more information on this code please read this article.
413 – Request Entity Too Large
The request is larger than the server is willing or able to process.
500 – Internal Server Error
This error is generally specific to something written in the .htaccess file that is not valid syntax or the website file permissions are in correct.
501 – Not Implemented
The server was not programmed to handle the type of request, or it was not able to fulful the request.