Chinese AI model Kimi K3.1 Pro is closing in on Anthropic's Claude Opus 5.5

Moonshot AI released Kimi K3.1 Pro, a post-trained successor to Kimi K3 that scores 55 points on the Artificial Analysis Intelligence Index, an 11-point gain that places it fourth behind Claude Opus 5.5 (58), Claude Sonnet 5.5 (56) and Muse Wonder Full (56). Moonshot says the model keeps K3's 2.8 trillion total and 104 billion active parameters with a one-million-token context window, cuts token prices by 33 percent, and shows its largest gains on agentic tasks, while cyber-related training data was stripped for the planned open-weights release. A faster K3.1 Pro Highspeed variant is also available through Kimi.ai, Kimi Work, Kimi Code and the Kimi API.