Moonshot AI

AI · Open-Source Models · Large Language Models

Launch

Moonshot AI releases Kimi K3, the largest open-source AI model ever

The Beijing lab's release marks a comeback after DeepSeek upended China's AI pecking order over the past 18 months.

• Moonshot AI released Kimi K3, a 2.8-trillion-parameter mixture-of-experts model, live now on Kimi.com, Kimi Code and its API, with full weights due July 27.
• Moonshot AI is a Beijing-based, Alibaba-backed startup that builds the Kimi chatbot and has bet on open-weight releases to compete with closed U.S. labs.
• K3 packs a 1-million-token context window and native vision, built on new Kimi Delta Attention and Attention Residuals architecture that enables up to 6.3x faster decoding at long contexts.
• API pricing is aggressive: $0.30 per million cached input tokens, $3 for non-cached input, and $15 per million output tokens.
• Within hours of launch, K3 climbed to No. 1 on Arena.ai's Frontend Code Arena leaderboard, edging out Anthropic's Claude Fable 5 on agentic coding tasks.
• The launch is timed just before the 2026 World Artificial Intelligence Conference in Shanghai, after Moonshot's market position had slipped since DeepSeek's rise.
• Moonshot is reportedly seeking a new funding round targeting a $31.5 billion valuation, up from the $20 billion mark set in a $2 billion raise this past May.
• A freely available model claiming near-parity with GPT-5.5 and Claude Opus 4.8 pressures the economics of paying for closed frontier AI, accelerating the shift toward open-weight alternatives.