On the web, what does the HTTP status code 404 mean?

The HTTP status code 404 means “Not Found.”

A web server returns 404 when it cannot find the requested resource at the address supplied by the client. The resource may have been deleted, moved, renamed, or entered incorrectly in the URL.

A 404 response does not necessarily mean that the entire website is offline. It usually concerns one requested page, image, or other resource. Website owners often create custom 404 pages with search tools or links back to the home page.

The code belongs to the HTTP 4xx class, which indicates an error associated with the client request. It differs from 500, which indicates a general internal server error, and 301, which indicates a permanent redirect.