Moonshot AI released the weights of its Kimi K3 model on July 27, 2026, making it publicly available for download and...

Moonshot AI released the weights of its Kimi K3 model on July 27, 2026, making it publicly available for download and inference. The model, which has 2.8 trillion parameters (104.2 billion activated), performs competitively with frontier models like OpenAI's GPT-5.6 Sol and Anthropic's Claude Fable, while being 2-3x cheaper to run and up to 10x cheaper with cached prompts (Source 1, Source 5). Moonshot also released a technical report detailing optimizations such as MXFP4 weights, a sparse mixture-of-experts architecture (16/896 experts active), and a novel attention mechanism called Kimi Delta Attention (Source 2, Source 3). The open-weight release is a direct challenge to the closed-model economics of US AI labs, as developers can run Kimi K3 on their own hardware and avoid API fees. Tom's Hardware notes that Moonshot's pricing is $3 per million input tokens versus $5 for Sol and $10 for Fable, with caching reducing costs further (Source 5). The Verge highlights that this move forces US companies to reconsider their closed strategies as developers gravitate toward open-weight alternatives (Source 7). CNBC reports that Kimi K3 has sparked a debate in Washington about restricting Chinese open-weight models, with Nvidia's Jensen Huang and others opposing premature restrictions (Source 8). The release also caused Moonshot's API demand to spike, leading to subscription pauses due to computing power limits (Source 8). Bloomberg's coverage positions Kimi K3 as a significant milestone in the US-China AI race (Source 6).

What the sources said:

• "Moonshot AI releases weights for Kimi-K3, firing a shot across the bow of OpenAI and Anthropic" (Source 5).
• "Why would an AI company spend vast sums of money training an AI model, only to give away some of the most valuable parts?" (Source 7).
• "The release of Kimi K3 has kicked off a hornet's debate in Washington about what to do about Chinese open-weight models" (Source 8).
• "For input, Moonshot charges $3 per million tokens for Kimi K3. Meanwhile, Fable costs $10/1M, while Sol goes for $5/1M" (Source 5).