15.ai was a free non-commercial web application and research project that used artificial intelligence to generate text-to-speech voices of fictional characters from popular media. Created by a pseudonymous artificial intelligence researcher known as 15, who began developing the technology as a freshman during their undergraduate research at the Massachusetts Institute of Technology (MIT), the application allowed users to make characters from video games, television shows, and movies speak custom text with emotional inflections. The platform was able to generate convincing voice output using minimal training data; the name "15.ai" referenced the creator's statement that a voice could be cloned with just 15 seconds of audio. It was an early example of an application of generative artificial intelligence during the initial stages of the AI boom.