Moonshot AI releases Kimi K3: a 2.8T-param open model that hits #1 in frontend coding

[AINews] Kimi K3 2.8T-A50B: the largest open model ever released; Opus 4.8-class at Sonnet 5 pricing

Moonshot AI launched Kimi K3, a 2.8T total-parameter model and the largest open-weight release to date. Weights are promised by July 27. It supports 1M-token context and native multimodal input, and is live on Kimi.com, Kimi Code, and the API. Artificial Analysis scored it 57 on the AA Intelligence Index—comparable to Claude Opus 4.8 and GPT-5.5, but still behind Claude Fable 5 and GPT-5.6 Sol. On LMSYS Frontend Code Arena, K3 hit #1 with 1679 points and a 76% win rate, well above Fable 5's 63%. Text Arena placed it at #9, a big jump from K2.6's #38. Moonshot itself flagged a noticeable UX gap versus Fable 5 and GPT-5.6 Sol. AA measured cost at $0.94 per task, with 21% fewer output tokens than K2.6.

Why it matters: Moonshot AI drops Kimi K3, a 2.8T-parameter model with weights promised by July 27 — the largest open-weight release to date. Performance targets Opus 4.8 at Sonnet 5 pricing. Domestic Chinese flagship model release gets the same weight as equivalent US lab launches per policy...