Kimi K3 

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Latest news on Kimi K3, Moonshot AI's frontier open-weight AI model, its benchmarks and industry reaction.

Kimi K3 is a 2.8 trillion-parameter open-weight model from Chinese AI lab Moonshot AI, built on a new attention architecture with native vision capabilities and a one-million-token context window. It is positioned as the first open model in the three-trillion-parameter class, targeting long-horizon coding, knowledge work, and reasoning. Its Mixture-of-Experts design activates only a small fraction of its experts per token, keeping inference efficient despite the model's scale.

Demand for the model was strong enough that Moonshot suspended new subscriptions within days of launch as capacity was overwhelmed. Independent testing placed Kimi K3 among the leading systems available today, ranking behind the top proprietary US models on general benchmarks while topping some coding and web development tests. The model is accessible through Moonshot's own apps, its API, and third-party hosting platforms, with full weights released under Moonshot's own licence.

The launch reignited a dispute between Washington and Beijing over how Chinese labs build frontier models. US officials alleged Moonshot covertly extracted capabilities from a rival American model during development, part of a wider allegation that Chinese labs had drawn on competitors' outputs at scale. Moonshot pushed back publicly, and some independent experts noted that this kind of practice is common across the industry rather than unique to Chinese labs. The episode has fed into broader talk of tighter export controls and possible sanctions on Chinese AI firms.

Kimi K3's release fits a pattern of Chinese labs favouring open weights to build developer mindshare quickly and cheaply. Moonshot's pivot to open-source models followed a rival's low-cost model disrupting the Chinese AI market, which had knocked Kimi down the domestic usage rankings. Cost-conscious developers have driven rapid adoption on hosting platforms, intensifying debate over whether open or closed models will shape the industry's future.

Moonshot AI was founded in Beijing in March 2023 by three Tsinghua University alumni and built its early reputation on long-context chat before expanding into its open-weight model family. The company followed its first open-weight release in 2025 with successive updates adding reasoning and multimodal capabilities, culminating in Kimi K3. Recent funding rounds have valued the company near twenty billion dollars, alongside reported preparations for a Hong Kong listing.

Follow our Kimi K3 feed for the latest on benchmarks, pricing, weight releases, and the ongoing dispute over the model's development as it unfolds.