Moonshot Releases Kimi K3.1 Pro: Scores 55 in Independent Benchmark, Promises Open Weights by November
Moonshot launched Kimi K3.1 Pro, scoring 55 on Artificial Analysis to rival frontier closed models, with a commitment to fully open-source weights by November 4.
Chinese AI company Moonshot released its new model, Kimi K3.1 Pro, on its API platform on October 23, 2026. According to tech blogger Simon Willison, the model weights are not yet open, but Moonshot has promised to release full model weights by November 4, 2026.
In tests by independent evaluation firm Artificial Analysis, Kimi K3.1 Pro scored 55. This result surpasses Claude Fable 5.1, GPT-6 Astra, and Gemini 4 Argon (all at 53), trailing only Claude Opus 5.5 (58). Willison noted that this is the first time a soon-to-be open-weight model has achieved such a high score against frontier closed models.
Regarding pricing, Kimi K3.1 Pro costs $2.00 per million input tokens and $10 per million output tokens. This price matches OpenAI's GPT-6.1 Sol and is half the cost of Anthropic's Claude Opus 5.5. Additionally, Moonshot offers a 'Highspeed' version that is 2-3x faster at twice the price, though cached input token prices remain unchanged.