Culture Crush

History of the 404

The surprising mythology and true meaning of the dreaded 404 page.

It’s happened to the best of us. You’re surfin’ the web, just doing your thing when suddenly you wipeout: 404 Page Not Found. It’s like opening a door only to find a brick wall on the other side. But why is it called 404? What does the number really mean? Where does it come from?

The Basics

404 is one of the standard status codes in Hypertext Transfer Protocol (HTTP), the computer-to-computer communication technique established in the 1990s at the dawn of the World Wide Web. HTTP is how your computer talks with other computers and servers when it navigates through websites. For every page you visit, your computer uses HTTP to request the data from a server. Before the site even shows up on your screen, the server and your computer have a little chat about what you’re looking for, your browser information, language, and more.

Here’s an example of just a small part the request that your computer sends to our server when you want to see the Thought Lab:

GET / HTTP/1.1

Our server looks for the page and then sends back its reply, which would include a line reading:

HTTP/1.1 200 OK

That “200 OK” code basically means: “Cool. I found that thing you wanted me to get and I’m sending it to you.” But if the server went to look for the page and saw that it wasn’t there, it would reply back with “404 Not Found.”

The Myth

There’s a cute myth floating out in the interwebs that these HTTP codes were originally based on the physical layout of CERN, the European Organization for Nuclear Research where the World Wide Web was first conceived as a database to help physicists share their findings. According to this 404 origin tale, HTTP codes were based on the different functions of physical offices at CERN, with Room 404 housing the system’s central database. Any request for a file was routed to that office where a few human staffers would manually find the file and transfer it over the network to the person who requested it. If the requested document couldn’t be located, the communicative office attendants would answer the request with “Room 404: file not found.” Allegedly this error response was later shortened when the system was automated, but continues to refer to Room 404 to this day.

The Truth

Hate to ruin a good story, but there never was a “Room 404” at CERN. The codes were defined by web inventor Tim Berners-Lee in 1992, based on the ones used for File Transfer Protocol in which codes beginning with 4 are essentially errors. The first 4 of the HTTP “404” actually indicates a client error like a misspelled URL or a moved page. The “0” points to a general syntax error like a spelling mistake, and the last “4” indicates the specific error in the family of “40-” errors which includes “400: Bad Request” and “403: Forbidden.”

Ironically, people have actually gone looking for Room 404 at CERN.

It hasn’t been found.

Got you hooked? here’s more:


404: Page Not Found
Renny Gleeson on how every 404 is an opportunity for fun


Ammar 404: Tunisia’s Big Brother
Censorship was so bad in Tunisia that the public invented a fictional 404-making character


60 Really Cool 404 Pages
Get a little inspiration for your own custom 404

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