Character AI is a web and mobile-first conversational platform built around user-created AI characters. Users can browse a large public library of characters or create their own by specifying personality descriptions, greetings, example messages, and behavioral tuning; created characters can be published for the community to discover. Conversations are open-ended and designed for multi-turn dialog, with tools to rate responses, refine character behavior, run multi-character group chats, and run text-adventure or roleplay scenarios.

The product targets casual and creative users, fan communities, writers and game designers, educators exploring conversational agents, and anyone who wants an interactive AI companion. Typical use cases include roleplaying with fictional or historical figures, prototyping dialog for games or stories, practicing language or interview scenarios, and light entertainment or companionship. The platform emphasizes community discovery and sharing—users frequently remix or iterate on published characters.

Character AI is offered as a primarily free service with optional paid subscription upgrades that provide faster responses, reduced wait times, and priority access to new features. Over time the company has introduced stricter safety controls, age-based access changes, and moderation improvements in response to content and child-safety concerns. The service is closed-source and operated by a private company; while it relies on large neural language models developed by the company, there is no broadly published open-source model or public developer API for general programmatic access.