Moonshot AI's Kimi K3.1 Pro ranks fourth on Artificial Analysis Intelligence Index, nearing Claude Opus 5.5

Moonshot AI released Kimi K3.1 Pro, a post-trained version of Kimi K3, achieving a score of 55 on the Artificial Analysis Intelligence Index, an 11-point increase from K3. This places it in fourth position, behind Claude Opus 5.5 (58), Claude Sonnet 5.5 (56), and Muse Wonder Full (56). K3.1 Pro shows significant gains in agentic tasks, reaching 1,846 Elo on GDPval-AA, just behind Claude Opus 5.5 (1,866). If Moonshot releases model weights by November 4, 2026, K3.1 Pro could become the highest-scoring open-weights model, narrowing the gap between open and proprietary models from 12 to 3 points.