Character.AI

Character.AI (also known as c.ai and char.ai) is a generative AI service publicly released in beta on September 16, 2022. It was founded by Noam Shazeer and Daniel de Freitas — both former Google engineers who had worked on the Transformer architecture and the experimental LaMDA model, respectively. The company was incorporated in November 2021 and raised a 150M USD round in March 2023 at an approximately 1B USD valuation.

The platform's core feature lets users create characters with custom personalities, parameters, and greeting messages, and then publish them for others to chat with. Characters span fictional figures and celebrities as well as original creations — often used as creative-writing assistants, text-adventure game guides, or role-play partners. Users can rate responses on a 1–4 star scale, which shapes character behavior. The service also includes multi-user group chat rooms where several humans and AI characters can converse simultaneously.

In May 2023 Character.AI launched iOS and Android mobile apps (more than 1.7M downloads in the first week) and a c.ai+ subscription (9.99 USD per month) offering priority access and faster responses. In August 2024 Google hired CEO Noam Shazeer and entered a non-exclusive licensing agreement for Character.AI technology. In December 2024 the company introduced a separate model for users under 18 with content filters, and on October 29, 2025 it announced that from November 25, 2025 minors will be barred entirely from chatting with characters, in response to lawsuits and concerns over teen safety.