Moonshot AI has introduced Kimi K3, its most capable model to date, positioning it as the world's first open 3T-class model. With 2.8 trillion parameters, Kimi K3 is built on novel architectural components—Kimi Delta Attention (KDA) and Attention Residuals (AttnRes)—and features native vision capabilities and a 1-million-token context window. The company states that while overall performance still trails proprietary leaders like Claude Fable 5 and GPT 5.6 Sol, Kimi K3 consistently outperforms other tested open models across their evaluation suite.
Kimi K3 is available immediately on Kimi.com, Kimi Work, Kimi Code, and the Kimi API. At launch, it defaults to 'max thinking effort,' with low- and high-effort modes planned for later updates. The full model weights are scheduled for release by July 27, 2026, with a technical report detailing architecture, training, and evaluations to follow. Moonshot is collaborating with inference partners and open-source maintainers to ensure a smooth ecosystem rollout.
The model's architecture introduces KDA and AttnRes to improve information flow across sequence length and depth, combined with a Mixture of Experts (MoE) design that activates 16 of 896 experts via a Stable LatentMoE framework. These changes yield an approximate 2.5× improvement in scaling efficiency over Kimi K2, enabling more effective conversion of compute into intelligence.
In benchmarks, Kimi K3 demonstrated strong long-horizon coding performance, including autonomous GPU kernel optimization, where it competed with Fable 5 and outperformed Opus 4.8, GPT 5.6 Sol, and GPT 5.5. It also built MiniTriton, a Triton-like compiler from scratch, achieving performance on par with or better than Triton and torch.compile on roofline benchmarks, and sustaining end-to-end nanoGPT training.
Beyond coding, Kimi K3 excels in vision-language tasks, 3D reasoning, and scientific research. It autonomously designed a chip for a nano model in 48 hours, and reproduced I-Love-Q universal relations in astrophysics in about two hours—a task typically requiring one to two weeks. In Kimi Work, new Widgets and Dashboard features enable interactive visualizations and persistent, personalized views.