Moonshot unveils Kimi K3, claims it is the world's largest open AI model

Chinese AI startup Moonshot AI has unveiled Kimi K3, a new large language model with 2.8 trillion parameters that the company describes as the world's largest open AI model.

According to Moonshot, K3 supports a context window of up to 1 million tokens and is natively multimodal, allowing it to process both text and images. The model is nearly three times larger than its predecessor, Kimi K2, and significantly exceeds the size of other leading open Chinese models, including DeepSeek with 1.6 trillion parameters and Xiaomi'smodel with 1.02 trillion.

Moonshot says K3 is designed for long-running coding tasks, document analysis, and complex reasoning. It is already available through the Kimi chatbot, Kimi Code, Kimi Work, and the company's API, priced at $3 per million input tokens and $15 per million output tokens. Full model weights, allowing developers to run K3 on their own hardware, are scheduled for release on July 27.

Naturally, the biggest question is how K3 compares with the best proprietary models. Moonshot says it still trails Anthropic's Claude Fable 5 and OpenAI's GPT-5.6 Sol in overall performance, but claims it outperforms every other competitor across most benchmark categories. Independent testing largely supports those claims. In the Arena blind evaluation platform, developers preferred K3 over leading US models for frontend development tasks. In the overall text ranking, K3 surpassed the standard version of Claude Opus 4.8, which until recently ranked among the strongest general-purpose models, and matched the performance of GPT-5.6 Sol.

Not all of the results are directly comparable. Moonshot ran its benchmarks with K3's highest reasoning setting enabled. According to Artificial Analysis, the new model is also more prone to hallucinations than its predecessor, generating inaccurate or fabricated information more frequently. Pricing has shifted as well. K3 is considerably more expensive than Kimi K2, with API costs now broadly comparable to mid-tier Western models. That may signal the end of the era of ultra-low-cost Chinese AI models, although OpenAI's and Anthropic's flagship systems remain significantly more expensive.

The launch coincides with the World Artificial Intelligence Conference (WAIC) in Shanghai, where Chinese AI companies traditionally unveil their biggest announcements. For Moonshot, K3 also represents a bid to become a major hub for the global open AI developer community. Founded in 2023 and backed by Alibaba, the company raised around $2 billion in May at a $20 billion valuation and is reportedly preparing another funding round that could value it at more than $30 billion.