Character.AI (also known as c.ai or Character AI) is a generative AI chatbot service where users can engage in conversations with customizable characters. It was designed by the developers of Google LaMDA, Noam Shazeer and Daniel de Freitas. Users can create "characters," craft their "personalities," set specific parameters, and publish them to the community for others to chat with. Many characters are based on fictional media sources or celebrities, while others are original, some being made with certain goals in mind, such as assisting with creative writing or playing a text-based adventure game.
The beta version was made available to the public on September 16, 2022, and retired in September 2024, when it was replaced by the current website. In May 2023, a mobile app was released for iOS and Android, which received over 1.7 million downloads within a week.
History
Character.AI was established in November 2021. The company's co-founders, Noam Shazeer and Daniel de Freitas, were both engineers from Google. They both worked on AI-related projects: Shazeer was a lead author on a paper that Business Insider reported in April 2023 "has been widely cited as key to today's chatbots," and Freitas was the lead designer of an experimental AI at Google initially called Meena, which later became known as LaMDA.
Character.AI raised $43 million in seed funding at the time of its initial foundation in 2021. The first beta version of Character.AI's service was made available to the public on September 16, 2022. The Washington Post reported in October 2022 that the site had "logged hundreds of thousands of user interactions in its first three weeks of beta-testing." It allowed users to create their own new characters and to play text-adventure game scenarios where users navigate scenarios described and managed by the chatbot characters.
Following a $150 million funding round in March 2023, Character.AI became valued at approximately $1 billion. As of January 2024, the site had 3.5 million daily visitors, the vast majority of them 16 to 30 years old.
In 2024, Google hired Noam Shazeer, the CEO of Character.AI, and entered into a non-exclusive agreement to use Character.AI's technology. This move was part of a broader trend in the Generative AI industry, where major tech companies sought to integrate advanced Large language model capabilities. The partnership allowed Google to leverage Character.AI's innovations while Character.AI gained access to Google's infrastructure, including Google Cloud services.
In October 2025, Character.AI announced that it would be barring users under the age of 18 from creating or talking to chatbots starting November 25, 2025. Minor users will still be able to access previously generated chat conversations and can create new videos and images with the app. In a November 2025 interview, CEO Karandeep Anand said that he allows his six-year-old daughter to use the app with his account, under supervision.
Features
Character.AI's primary service is to let users converse with character AI chatbots based on fictional characters or real people (living or deceased). These characters' responses use data the chatbots gather from the internet about a person. In addition, users can play text-adventure games where characters guide them through scenarios. The company also provides a service that allows multiple users and AI chatbot characters to converse together at once in a single chatroom.
Character "personalities" are designed via descriptions from the point of view of the character and its greeting message, and further molded from conversations made into examples, giving its messages a star rating and modification to fit the precise dialect and identity the user desires. When a character sends back a response, the user can rate the response from 1 to 4 stars. The rating predominantly affects the specific character, but also affects the behavioral selection as a whole.
On May 11, 2023, Character.AI announced character.ai+, an opt-in subscription plan for $9.99 a month, that was marketed as including features such as skipping waiting rooms, fast messaging and responses, and access to an exclusion channel with faster support.
In December 2024, amid multiple lawsuits and concerns, Character.AI introduced new safety features aimed at protecting teenage users. These enhancements include a dedicated model for users under 18, which moderates responses to sensitive subjects like violence and sex and has input and output filters to block harmful content. As a result of these changes and the deletion of custom-made bots flagged as violating the site's terms, some users complained that the bots were too restrictive and lacked personality. The platform was also updated to notify users after 60 minutes of continuous engagement, and display clearer disclaimers indicating that its AI characters are not real individuals.
In January 2025, Character.AI began offering two games on its platform. Speakeasy is a word-based game in which players attempt to prompt the AI chatbot to say a target word while avoiding a restricted list of words. War of Words is a dueling game where users compete against an AI character over multiple rounds, with an AI referee determining the winner. The games are available to paid subscribers and a limited number of free users.
In July 2026, Character.AI launched c.ai Series, microdramas animated using generative AI.
Technology and Model Updates
Character.AI's underlying technology relies on Deep learning and Neural network architectures, particularly Transformer (architecture) models. The service uses a proprietary Large language model that is fine-tuned for conversational interactions, distinguishing it from general-purpose models like those from OpenAI or Anthropic. The company has focused on optimizing the model for character consistency and emotional engagement, which involves techniques such as Reinforcement Learning from AI Feedback (RLAIF) (reinforcement learning from AI feedback) and Curriculum Learning to improve response quality.
In 2024, Character.AI introduced a new model architecture that enhanced the ability of characters to maintain long-term memory and context across conversations. This update, which was not publicly detailed, reportedly reduced instances of characters forgetting earlier parts of a dialogue. The company also experimented with Multi-Head Attention mechanisms to improve the coherence of responses in multi-character chatrooms.
Character.AI's infrastructure has evolved to handle high volumes of daily interactions. The service relies on Amazon Web Services and Google Cloud for scalable compute, with AWS Trainium chips used for some training workloads. The company has also explored partnerships with AMD and Intel to optimize inference costs, though specific details remain undisclosed.
Controversies
Content Moderation Issues
Character.AI has been criticized for poor moderation of its chatbots, with incidents of chatbots that groom underage users and promote suicide, anorexia and self-harm being reported.
In October 2024, the Washington Post reported that Character.AI had removed a chatbot based on Jennifer Ann Crecente, a person who had been murdered by her ex-boyfriend in 2006. The company had been alerted to the character by the deceased girl's father. Similar reports from The Daily Telegraph in the United Kingdom noted that the company had also been prompted to remove chatbots based on Brianna Ghey, a 16-year-old transgender girl murdered in 2023, and Molly Russell, a 14-year-old suicide victim. In response to the latter incident, Ofcom announced that content from chatbots impersonating real and fictional people would fall under the Online Safety Act.
In November 2024, The Daily Telegraph reported that chatbots based on alleged sex offender Jimmy Savile were present on Character.AI. In December 2024, chatbots of Luigi Mangione, the suspect in the killing of UnitedHealthcare CEO Brian Thompson, were created by Mangione's fans. Several of the chatbots were later removed by Character.AI.
In 2025, a chatbot modeled after Jeffrey Epstein called "Bestie Epstein" logged nearly 3,000 chats before being removed. Chatbots modeled after school shooters were also found on the platform. Another concern is a chatbot posing as a doctor which gave medically inaccurate advice.
Litigation
In November 2023, 13-year-old Juliana Peralta of Colorado died by suicide after extensive interactions with multiple chatbots on Character.AI. She primarily confided suicidal thoughts and mental health struggles in a chatbot based on the character Hero from the video game Omori, while also engaging in sexually explicit conversations with other bots. Her mother filed a lawsuit against Character.AI in October 2024, alleging negligence and wrongful death. The lawsuit claimed that the company's products were "dangerous and defective" and that the chatbots had "groomed" the teenager, encouraging her to self-harm and suicide. Character.AI responded by stating that it was "deeply saddened" by the tragedy and that it had implemented new safety features, including a model for under-18 users and clearer disclaimers.
In December 2024, a federal judge in Texas allowed a separate lawsuit against Character.AI to proceed, involving a 15-year-old boy who allegedly became obsessed with a chatbot and threatened violence. The case raised questions about the liability of AI companies for user-generated content and the effectiveness of moderation tools.
Safety and Regulation
Character.AI's safety measures have evolved in response to public pressure and regulatory scrutiny. The company has partnered with external organizations to review its moderation policies, though specific partners have not been named. In 2025, Character.AI began cooperating with UK regulators, including Ofcom, to ensure compliance with the Online Safety Act, which now covers AI-generated content that impersonates real individuals.
The company has also invested in Data Augmentation techniques to train its models to recognize and avoid harmful prompts. However, critics argue that these measures are insufficient, as evidenced by the continued presence of problematic chatbots. Character.AI has stated that it uses a combination of automated filters and human moderators to review content, but the sheer volume of user-created characters makes comprehensive oversight challenging.
Impact and Reception
Character.AI has had a significant impact on the Generative AI landscape, popularizing the concept of personalized AI companions. Its success has influenced other companies, such as Inflection AI and AI21 Labs, to develop similar chatbot services. The platform has been praised for its creative potential, allowing users to explore storytelling and role-playing in ways not possible with traditional Artificial intelligence tools.
However, the company has faced criticism for its handling of sensitive content and the potential psychological effects on vulnerable users, particularly teenagers. Researchers at institutions like MIT CSAIL and Stanford AI Lab have studied the ethical implications of AI companions, noting that prolonged interactions with chatbots can lead to emotional dependence. Character.AI has acknowledged these concerns and has funded studies on user well-being, though results have not been publicly released.
As of 2026, Character.AI continues to operate as a major player in the AI chatbot market, with a user base that spans multiple age groups and geographies. The company's future direction remains uncertain, given ongoing legal challenges and evolving regulatory frameworks.