Kimi K3.1 Pro Pricing, Evaluation Scores, and Open Weights

Moonshot announced Kimi K3.1 Pro on October 23, 2026, cutting API prices to $2.00 per million input tokens and $10 per million output tokens while scheduling full open weights for release by November 4, 2026.12

Moonshot reported that claim-level hallucination on its internal Kimi Hallu Bench Hard stress test dropped from 23.4% on K3 down to 8.3% on K3.1 Pro.1

Performance and published evaluations

As of October 23, 2026, the Artificial Analysis Intelligence Index ranked Kimi K3.1 Pro fourth with a score of 55. Moonshot also made Kimi K3.1 Pro Highspeed available, which delivers 2 to 3 times the speed of the standard K3.1 Pro model.31

The cost of safety in model training

To reduce misuse risks ahead of public weight distribution, Moonshot identified and removed cyber-related training data from both the mid-training and reinforcement learning stages.1

On the internal xdev-bench-hard benchmark, an unfiltered checkpoint without data removal or RL filtering solved 90.5% of problems at pass@3. The safety-filtered K3.1 Pro dropped to 81.0%, showing an explicit trade-off between open distribution safety and high-end software development execution.1

Pricing shifts from K3 to K3.1 Pro

Moonshot lowered API costs across both input and output tiers. According to data tracked on our open model release tracker, the original Kimi-K3 launched on June 13, 2026, with 2779.9B parameters under the kimi-k3 licence.4

Our pricing logs captured on October 13, 2026, recorded kimi-k3 at $3 input and $15 output per million tokens. The shift to $2.00 input and $10 output is a cut of a third on both.52