418x Apr 2026

It’s the ultimate "if you know, you know" for programmers—a reminder that the people who built the backbone of our digital world still had a sense of humor.

Many web frameworks still support 418 as a valid (albeit humorous) response. It’s the ultimate "if you know, you know"

For those unfamiliar with the deep lore of the internet, the is a classic piece of tech humor that has endured for decades. What is it? It’s the ultimate "if you know

The specific error is returned by a teapot when it is requested to brew coffee. According to the spec: It’s the ultimate "if you know, you know"

In 1998, the Internet Engineering Task Force (IETF) released as an April Fools' Joke. It defined the "Hyper Text Coffee Pot Control Protocol" (HTCPCP).