Chinese AI firm Moonshot AI announced its Kimi K3 model, which it stressed was the first open model (not open-source model) to reach 2.8 trillion parameters.

It also has a 1-million-token context window, with the company noting that Kimi K3 yielded about 2.5× improvement in overall scaling efficiency when compared to Kimi K2.

“Kimi K3 is a 2.8T-parameter model built on our Kimi Delta Attention and Attention Residuals, with native vision capabilities and a 1-million-token context window.

It is the world’s first open 3T-class model, designed for frontier intelligence across long-horizon coding, knowledge work, and reasoning,” Moonshot AI said in a blog.

China issues 'backdoor' security alert over Anthropic's Claude Code The startup acknowledged that the overall performance of Kimi K3 trailed that of “powerful proprietary models” from the U.S. such as Claude Fable 5 and GPT 5.6 Sol, but that it delivered frontier-level performance across its evaluation suite and outperformed older rival models from the U.S. across several benchmarks.

American AI companies and technologists have raised concerns about Chinese AI firms releasing competitive frontier models at what they claim are far cheaper rates.

Several U.S. firms also suspect that Chinese AI companies are “distilling” their data to build AI models at lower costs and draw in more users.

Anthropic claimed that it had identified industrial-scale campaigns by DeepSeek, Moonshot, and MiniMax to “illicitly extract Claude’s capabilities to improve their own models.” “These labs generated over 16 million exchanges with Claude through approximately 24,000 fraudulent accounts, in violation of our terms of service and regional access restrictions,” stated Anthropic in a post in February.

Make China leading power in sci-tech by 2035: Xi tells scientists Moonshot AI’s website stated that its research team worked toward AGI while sharing the latest research with the global open-source community.

While AI giants in the U.S. have focused on closed, flagships models in an effort to justify rising token prices for users and heavy investments, Chinese companies have delivered a series of customisable open-weight models with less of a focus on proprietary rights.

Moonshot AI noted that the full model weights will be released by July 27.

The company is backed by Chinese tech titans Alibaba and Tencent.