Moonshot AI Releases Kimi K3.1 Pro, Plans Weight Release Before Nov. 4

Moonshot AI has released Kimi K3.1 Pro, a new AI model that scored 65.70% on Terminal-Bench 4.0, placing it between OpenAI's GPT-6 Astra and Anthropic's Claude Opus 5.5.

The score was 7.50 percentage points higher than GPT-6 Astra's 58.20% and 0.70 points lower than Claude Opus 5.5's 66.40%.

Moonshot also released Kimi K3.1 Pro Highspeed, a variant that runs two to three times faster than the standard model. Both versions are available through Kimi.ai, Kimi Work, Kimi Code and the API, and each supports a context window of up to 1 million tokens.

An internal test put K3.1 Pro's single-claim hallucination rate at 8.30%, compared with 23.40% for K3.

K3.1 Pro is the first model in the K3.1 series, following Moonshot AI's July release of Kimi K3. The full model weights are planned for release before Nov. 4.