Moonshot has released Kimi K3.1 Pro, an upgraded version of its open-weight Kimi K3, with full weights due by 4 November. It says the model nearly matches Claude Opus 5.5 on a coding test. Moonshot also says it removed hacking-related training data to limit misuse of the open release.

Chinese AI lab Moonshot has released Kimi K3.1 Pro, an upgraded version of its open-weight model, the company said on Friday. It is available now in Kimi’s apps and API, and Moonshot plans to publish the full model weights by 4 November.

K3.1 Pro builds on Kimi K3 , a model with nearly 3 trillion parameters, with much more training on top. Moonshot also released a Highspeed version that it says runs two to three times faster.

On Terminal-Bench 4.0, a test of AI coding agents, K3.1 Pro scored 65.7%, Moonshot said. That puts it ahead of OpenAI’s GPT-6 Astra at 58.2% and just behind Anthropic’s Claude Opus 5.5 at 66.4%.

The figures are Moonshot’s own and have not been checked independently.…