Understanding HTTP Error Codes

Nobody would like visitors to see an HTTP error code when visiting their website; however, it happens. HTTP error codes exist to tell the visitor that there was an issue accessing the requested page. HTTP error codes are the 400- and 500-series codes; 400-series codes identify client request errors and 500-series codes identify server-side errors.

The web server (e.g., Apache or IIS for instance) will provide a generic error page; however, these error pages are customizable using cPanel. Custom error pages are often preferable because additional, user-friendly information can be provided; other times, an error-page themed to your site content is preferable because it maintains the user experience as much as possible.

Editing error codes in cPanel

cPanel provides a simple, graphical user interface to customize error codes. To customize error codes for your domain :

1. Go to yourdomain.com/cpanel and log in
2. Click on the Error Pages icon in the Advanced menu

   

3. Click on the desired error code to modify

   

4. Customize the error page by clicking on the buttons provided

   

5. Alternately, you can upload a file of the same name. For example, if you upload a file named 404.shtml and overwrite the existing file, visitors will see your custom error message
6. Click the Save button at the bottom of the window

   

7. Test your new error page! In this case, try a page that you know will not be found and will result in a 404 error

Error code definitions

The World Wide Web Consortium (W3C) defines the error codes as follows:

Client Request Errors

400 Bad Request

• The request could not be understood

401 Authorization Required

• This request requires authentications

402 Payment Required (reserved)

403 Forbidden

• The server understood the request but refuses to fulfill it

404 Not Found

• The server has not found a matching document

405 Method Not Allowed

• The method specified in the request line is not allowed

406 Not Acceptable (encoding)

• The resource identified by the request is only capable of generating response entities which have content characteristics not acceptable according to the accept headers sent in the request

407 Proxy Authentication Required

• Similar to 401 (Unauthorized), but indicates that the client must first authenticate itself with the proxy

408 Request Timed Out

• 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

410 Gone

• The requested resource is no longer available at the server and no forwarding address is known

411 Content Length Required

• The server refuses to accept the request without a defined Content-Length

412 Precondition Failed

• The precondition given in one or more of the request-header fields evaluated to false 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

• A rare condition where the server is refusing to service the request because the Request-URI is longer than the server is willing to interpret

415 Unsupported Media Type

• The server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method

416 Requested Range Not Satisfiable

• A server SHOULD return a response with this status code if a request included a Range request-header field (section 14.35), and none of the range-specifier values in this field overlap the current extent of the selected resource, and the request did not include an If-Range request-header field

417 Expectation Failed

• The expectation given in an Expect request-header field could not be met by this server, or, if the server is a proxy, the server has unambiguous evidence that the request could not be met by the next-hop server

Server Errors

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, while acting as a gateway or proxy, 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. The implication is that this is a temporary condition which will be alleviated after some delay

504 Gateway Timeout

• The server, while acting as a gateway or proxy, did not receive a timely response from the upstream server specified by the URI (e.g. HTTP, FTP, LDAP) or some other auxiliary server (e.g. DNS) it needed to access in attempting to complete the request

505 HTTP Version Not Supported

• The server does not support, or refuses to support, the HTTP protocol version that was used in the request message