The HTTP status code from an April Fools’ RFC named “I’m a teapot” is 418.
Code 418 comes from RFC 2324, the Hyper Text Coffee Pot Control Protocol, published on April 1, 1998. Written by Larry Masinter, the RFC humorously described a protocol for controlling, monitoring, and diagnosing networked coffee pots. It introduced coffee-themed methods and terminology while treating kitchen appliances as if they were serious Internet infrastructure.
The specification says that an attempt to brew coffee with a teapot should return “418 I’m a teapot.” Its accompanying response body may be “short and stout,” echoing the children’s song “I’m a Little Teapot.” The code was never intended as an ordinary production HTTP error.
Although 418 began as a joke, developers later used it as an Easter egg, a playful response, or occasionally a signal that a request was blocked. HTTP’s modern standards documentation lists 418 as unused, while acknowledging that the joke code became widely recognized. It is not the same as 404 Not Found, 500 Internal Server Error, or 301 Moved Permanently.