Kimi K3.1 Pro: Moonshot's new model with upcoming open weights
In brief
- Moonshot releases Kimi K3.1 Pro via API today.
- Full model weights promised by November 4, 2026.
- Priced at $2/M input tokens and $10/M output tokens, half the cost of Claude Opus 5.5.
Moonshot launched Kimi K3.1 Pro today through its API, with full model weights set to be released by November 4, 2026. A "Highspeed" version, two to three times faster but twice as expensive, is also available. The pricing is $2 per million input tokens and $10 per million output tokens, half the cost of Claude Opus 5.5 according to public rates. Moonshot's benchmarks show Kimi K3.1 Pro competing with Opus 5.5 and GPT-6 Astra, while Artificial Analysis rates it at 55, ahead of several competitors.
The model is accessible via Moonshot's API and can be tested using the LLM 0.32 tool, compatible with OpenAI-compatible endpoints. Its upcoming open weights make it one of the few high-performing models in this category, a first according to available announcements.
This summary gives you the essentials. The full article, its figures and quotes are on Simon Willison's Weblog.
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