Kimi K3.1 Pro
Released on October 23, 2026
Changes from previous version
Follows Kimi K2.8 Preview on the release calendar, and is a post-train of Kimi K3. List rates fall from K3's $3/$15 to $2/$10, with cache reads at $0.20. Kimi Code Bench 3.0 Long-horizon rises from 55.95% for K3 to 61.2%. Terminal-Bench 4.0 on the announcement chart is 65.7%.
Release Summary
Post-trained Kimi K3 from Moonshot AI: 2.8 trillion total parameters and 104 billion active, with text, image, and video input. Context is 1,048,576 tokens. The API default output cap is 131,072 tokens and can be raised to the full context. API id kimi-k3.1-pro. Reasoning is always on, with reasoning_effort low, high, or max, and max is the default. List price is $2 per million input tokens, $0.20 cache reads, and $10 output. Cache writes are $2 for a 5-minute TTL and $4 for 1 hour. Highspeed (kimi-k3.1-pro-highspeed) is the same checkpoint at 2-3x speed for $4/$20, with the same $0.20 cache read. On the announcement chart at max effort, Terminal-Bench 4.0 is 65.7% with Claude Code, ahead of GPT-6 Astra at 58.2% and behind Claude Opus 5.5 at 66.4%. SWE-Marathon v1.1 is 51.7% with the same harness. OfficeQA Pro v2 is 64.4. Measured price per task is $2.11. Weights are scheduled by November 4, 2026. Available on kimi.ai, Kimi Work, Kimi Code, and the Kimi API.
Timeline
Kimi K3.1 Pro released
Moonshot AI launches Kimi K3.1 Pro and the Highspeed serving mode on kimi.ai, Kimi Work, Kimi Code, and the Kimi API, with weights scheduled by November 4, 2026.