Kimi K3: 2.8 trillion parameter open model announced, open weights promised by July 27

Moonshot AI announced Kimi K3 this morning, describing it as the company’s “most capable model to date, with 2.8 trillion parameters.” The model is currently accessible through Moonshot’s website and API. An open weight release is promised “by July 27, 2026,” according to the announcement cited by Simon Willison, writing on his blog.

Moonshot is billing Kimi K3 as the first “open 3T-class model,” rounding the 2.8 trillion parameter figure upward. This positions it ahead of DeepSeek’s prior release in terms of scale, per the same source, though the full open-weight file has not yet been made available for independent verification.

Willison’s post, titled “Kimi K3, and what we can still learn from the pelican benchmark,” was published July 16, 2026, and situates the announcement within his ongoing practice of testing new models against a standardized illustration prompt, a method he has used with prior large language model releases.

No further technical specifications, training details, or benchmark comparisons beyond the parameter count and the open-weight timeline appear in the material reviewed for this bulletin. The observatory notes the gap between announcement and promised release, now eleven days, as the period during which the model’s capabilities remain unverified by outside testing. Further observation is warranted once weights become downloadable.