Moonshot's Kimi K3.1 Pro Narrows Gap With Top AI Rivals

Kimi K3.1 Pro has secured the fourth position on the Artificial Analysis Intelligence Index with a score of 55 points, placing it within striking distance of the industry leaders.

The model, released by Chinese AI firm Moonshot AI, represents a substantial upgrade over its predecessor, Kimi K3. The new version posts an 11-point increase in its overall intelligence score. Currently, only three models rank higher on the index: Claude Opus 5.5 with 58 points, followed by Claude Sonnet 5.5 and Muse Wonder Full, both at 56 points. This places K3.1 Pro just three points behind the top proprietary models, a significant shift in the competitive landscape.

Moonshot AI is positioning this release as a major step for open-source models. If the company releases the model weights by November 4, 2026, K3.1 Pro is set to become the highest-scoring open-weights model available. Such a move would reduce the performance gap between open and proprietary systems from 12 points to a mere three, assuming no other major releases occur in the interim. The company is also offering a variant called K3.1 Pro Highspeed, which the firm claims runs two to three times faster than the standard version.

The most notable improvements are found in agentic tasks and coding. On the GDPval-AA benchmark, K3.1 Pro achieves an Elo rating of 1,846, a 312-point leap from the previous version. In Terminal-Bench 4.0, the model scores 65.7 percent, outperforming GPT-6 Astra and trailing only Claude Opus 5.5, which recorded 66.4 percent. By comparison, the older K3 model managed just 13 percent on that same test. Additionally, internal testing shows a sharp decline in hallucinations, with claim-level errors dropping from 23.4 percent to 8.3 percent, though GPT-6 Astra still holds an edge at 5.5 percent.

Beyond general coding, the model demonstrates strong capabilities in 3D modeling. Moonshot states that K3.1 Pro can interact directly with game engines such as Unity, Unreal Engine, and Godot. On the BenchCAD benchmark, the model scores 92.7 percent when using tools, a figure close to both Claude Opus 5.5 and GPT-6 Astra. The company highlights the model's strength in parametric modeling for mechanical parts and architecture, and it has launched a "3D Make" feature on Kimi.com to allow users to preview and export models.

Despite the performance gains, the model retains the same architecture as its predecessor, with 2.8 trillion total parameters and 104 billion active ones. However, the cost of using the model has decreased significantly. API prices have dropped by 33 percent, with input costs now at $2 per million tokens and output at $10. Moonshot notes that the model sits at the top of the Pareto frontier, meaning no other model with a comparable parameter count scores higher on the intelligence index.

The stakes for the broader AI market are high as the distinction between open and closed models blurs. Moonshot has addressed cybersecurity concerns by removing cyber-related data from the training phase for the open-weights release. This data cleaning reduced the model's ability to solve vulnerability tasks from 90.5 percent to 81.0 percent, a calculated trade-off to balance offensive capabilities with defensive utility. As these models become more capable and affordable, they are poised to reshape how businesses approach software development and system auditing.