Myth busting

Myth busting the ‘404 Page not found’ story

Whenever we type in a non-existent web address (may be the url typed was incomplete or misspelled or the page no longer exists), we get a ‘404 - Page not found’ error. Which we have seen umpteen number of times. But why the error code '404'?

When internet was in its infancy, and was confined to CERN's internal network, in an office on the fourth floor (room 404), they placed the World Wide Web's central database: any request for a file was routed to that office, where requested files were located and transferred over the network, to the person who made that request. When faulty requests were made, for which files were not present, the standard message was: 'Room 404: file not found'. The room numbers remained in the error codes in the official release of HTTP when the Web left CERN to conquer the world, and are still displayed when a browser makes a faulty request to a Web server.

I am sure all of us would have heard this story. But is this true? Turns out, its just a popular myth.

Why 404 then? HTTP status codes were established by the World Wide Web Consortium (W3C) in 1992, as a part of the HTTP 0.9 spec. They were defined by Tim Berners-Lee. Berners-Lee based the HTTP status codes on FTP status codes.

The first '4' indicates a client error. The server is saying that you've done something wrong, such as misspelled URL or request to a page which is no longer there. Conversely, a 5xx error indicates a server-side problem. The middle '0' refers to a general syntax error. The last '4' just indicates the specific error in the group of 40x, which also includes 400: Bad Request, 401: Unauthorized, etc.

Further, there is no room 404 in CERN! The offices in building 4 at CERN start at 410 and work upwards.

So, myth busted :)