Character.ai is a neural language model chatbot service that can generate human-like text responses and participate in contextual conversation. Constructed by previous developers of Google's LaMDA, Noam Shazeer, and Daniel De Freitas, the beta model was made available to use by the public in September 2022.

Users can create "characters", craft their "personalities", set specific parameters, and then publish them to the community for others to chat with. Many characters may be based on fictional media sources or celebrities, while others are completely original, some being made with certain goals in mind such as assisting with creative writing or being a text-based adventure game.

In May 2023, the service added a monthly subscription option and a mobile app was released for both the Apple App Store and Google Play Store.