Chai
Mobile-first AI character chat powered by in-house LLMs tuned for personality.
About
Chai is a mobile-first platform for creating and chatting with custom AI characters, focused on open-ended roleplay and personality-driven conversation rather than factual Q&A. It launched on the App Store in February 2023, ahead of Character AI and ChatGPT consumer apps, and now serves over one million daily active users with average session times around 90 minutes.
Unlike apps built on third-party APIs, Chai trains hundreds of in-house language models using RLHF, model blending, DPO, and GRPO on user engagement signals, running on its own 1.4 exaflop GPU cluster serving 1.2 trillion tokens per day. It offers free character chat with premium and ultra subscriptions for extra features. Safety filters and anonymous reporting are built in, though memory depth and privacy posture are weaker than dedicated companion apps.
What it can do
- Browse community-created AI personalities
- Build custom characters and storylines
- In-house LLMs tuned for engaging conversation
- Safety filters and anonymous in-app reporting
Setup
Download the Chai app on iOS or Android and create an account.
Prerequisites
A smartphone; a web client is listed as coming soon.
Use cases
Works with
Trust score — 8/10
Scored 8/10 (verified tier, metrics-v1). Evidence: Verified via vendor site/docs/GitHub and reputable coverage, wave 80; Trending score 76/100 from researcher assessment.
Sources
Every fact above was checked against these sources. Where a claim comes from the provider and couldn't be independently verified, the text says so.