China’s AI startup Moonshot has introduced Kimi K3, a 2.8 trillion-parameter model that the company says is the world’s largest open-weight AI system. According to Moonshot, the model delivers performance close to Anthropic’s frontier Fable model, highlighting the rapid progress of China’s AI ecosystem.
The launch comes 1 month after Anthropic’s Fable and Mythos models were withdrawn by the U.S. government over security concerns. It also reflects how Chinese AI companies are quickly narrowing the performance gap with leading U.S. AI systems. Companies such as Moonshot, Z.ai, and MiniMax are releasing increasingly advanced models at significantly lower costs, challenging the belief that Chinese AI developers lag behind their U.S. counterparts.
Moonshot said Kimi K3 is the first open-weight model to approach the 3 trillion-parameter milestone. It is designed for advanced reasoning, long-horizon coding, and knowledge-intensive tasks. The model features a 1 million-token context window, enabling it to process and retain much larger amounts of information in a single prompt than earlier AI models.
The company stated that Kimi K3 “performed competitively with Fable 5 (with fallback) and substantially outperformed (OpenAI’s) Opus 4.8, GPT 5.6 Sol, and GPT 5.5” in GPU kernel optimisation, a technique that improves AI hardware efficiency while reducing latency. The model has also delivered strong results in independent evaluations.
Arena.ai ranked Kimi K3 1st for web interface-building capabilities, while Vals AI placed it 2nd, behind Fable 5 and ahead of GPT-5.6 Sol. Artificial Analysis reported that the model offers performance comparable to OpenAI’s GPT-5.5 and Anthropic’s Claude Opus 4.8, particularly on complex, multi-step reasoning tasks.
Following the announcement, shares of Chinese AI companies Zhipu and MiniMax fell 21.9% and 13.8%, respectively, in Hong Kong trading. The launch comes as Chinese AI companies continue to accelerate model development. Earlier, Z.ai introduced GLM-5.2, while MiniMax announced plans to launch its 2.7 trillion-parameter model in Q3 2026, followed by its frontier-level multimodal model H3.
Before Kimi K3, Meituan’s LongCat-2.0 and DeepSeek’s V4-Pro led China’s AI industry with 1.6 trillion parameters. Open-weight models allow users to download, run, and customize AI systems, unlike proprietary closed-source models. Moonshot said Kimi K3 also includes 2 architectural upgrades that improve computing efficiency and support long-horizon coding tasks with minimal human supervision.
Backed by Alibaba and Tencent, Moonshot continues to expand its AI capabilities and investment. Last month, reports indicated the company was seeking $2 billion in funding at a valuation of around $30 billion ahead of a potential Hong Kong listing.
Also read: Viksit Workforce for a Viksit Bharat
Do Follow: The Mainstream LinkedIn | The Mainstream Facebook | The Mainstream Youtube | The Mainstream Twitter
About us:
The Mainstream is a premier platform delivering the latest updates and informed perspectives across the technology business and cyber landscape. Built on research-driven, thought leadership and original intellectual property, The Mainstream also curates summits & conferences that convene decision makers to explore how technology reshapes industries and leadership. With a growing presence in India and globally across the Middle East, Africa, ASEAN, the USA, the UK and Australia, The Mainstream carries a vision to bring the latest happenings and insights to 8.2 billion people and to place technology at the centre of conversation for leaders navigating the future.