# It's 404 week at Webmaster Central

Monday, August 11, 2008


This week we're publishing several blog posts dedicated to helping you with one response code:
`404`.
[Response codes](https://wikipedia.org/wiki/List_of_HTTP_status_codes)
are a numeric status (like `200` for "OK", `301` for "Moved Permanently")
that a webserver returns in response to a request for a URL. The `404` response code
should be returned for a file "Not Found".


When a user sends a request for your webpage, your webserver looks for the corresponding file for
the URL. If a file exists, your webserver likely responds with a `200` response code
along with a message (often the content of the page, such as the HTML).
![200 response code flow chart](https://developers.google.com/static/search/blog/images/import/7ca9b8decf36db17266b22c8ec9e8fce.png)


So what's a `404`? Let's say that in the link to "Visit Google Apps" above, the link is
broken because of a typing error when coding the page. Now when a user clicks "Visit Google Apps",
the particular webpage/file isn't located by the webserver. The webserver should return a
`404` response code, meaning "Not Found".
![404 response code flow chart](https://developers.google.com/static/search/blog/images/import/dca8c58e19a3260ec0f84bf2cd142403.png)


Now that we're all on board with the basics of `404` errors, stay tuned for even more
information on making `404` errors good for users and for search engines.

Written by [Maile Ohye](https://developers.google.com/search/blog/authors/maile-ohye), Developer Programs Tech Lead