Moonshot AI releases Kimi K3.1 Pro, tops open-weight model index
Kimi K3.1 Pro scored 55 on the Artificial Analysis Intelligence Index, ranking fourth overall. Moonshot AI says full weights arrive by November 4.
Moonshot AI released Kimi K3.1 Pro on October 23, the first model in its K3.1 series. The model scored 55 on the Artificial Analysis Intelligence Index, placing it 4th overall and 1st among open-weight models, according to aitimes.com.
Kimi K3.1 Pro has 2.8 trillion total parameters and 104 billion active parameters, the same as Kimi K3, with a 1 million token context. It is available on the Kimi website, the mobile app, Kimi Work, Kimi Code and the API. Moonshot AI plans to publish the full model weights by November 4.
On coding benchmarks, the model scored 65.7% on Terminal Bench 4.0, above GPT-6 Astra's 58.2% and close to Claude Opus 5.5's 66.4%. It scored 64.4 on OfficeQA Pro v2 and 1846 on GDPval-AA v2.1, placing third. In Code Arena WebDev it reached 8th place with 1692 points.
API pricing is set at $2 per million input tokens, $10 per million output tokens and $0.2 for cached input, 33% lower than Kimi K3. Moonshot AI also released Kimi K3.1 Pro High Speed, a faster version priced at $4 per million input tokens and $20 per million output tokens.
Moving up from K3
Kimi K3, the previous model, scored 44 on the Artificial Analysis Intelligence Index and ranked 17th in Code Arena WebDev. Before this release, users tested an anonymous model called "Kibits" in the arena and speculated it was Kimi K3.1.
Quick answers
When will Kimi K3.1 Pro's weights be released?
Moonshot AI plans to publish the full model weights by November 4.
How much does Kimi K3.1 Pro cost through the API?
$2 per million input tokens, $10 per million output tokens and $0.2 for cached input, 33% lower than Kimi K3.
Where can I use Kimi K3.1 Pro?
It is available on the Kimi website, the mobile app, Kimi Work, Kimi Code and the API.