What phrase does the HTTP status code 404 represent?

The HTTP status code 404 represents “Not Found.” It means a server was reached, but it could not locate or provide the resource requested by the client.

The first digit, 4, identifies a client-error response, while the remaining digits identify the particular condition. A 404 commonly appears when a URL is mistyped, a page has been deleted, or a site has moved content without preserving the old address.

A 404 is not the same as a DNS failure: with a 404, the server itself is generally reachable. It is also different from 301 Moved Permanently, which tells clients that a resource has a new permanent location, and 410 Gone, which more explicitly indicates that a resource was intentionally removed.

Websites often replace the plain server response with a custom “404 page,” sometimes adding search tools or links to popular sections. The phrase is so familiar that “404” is now widely used as shorthand for something missing, even outside web technology.