China’s Moonshot launches Kimi K3 open AI model

Chinese AI company Moonshot has introduced Kimi K3, which it describes as the world’s largest open-weight AI model with 2.8 trillion (tn) parameters.

The announcement follows recent developments in the global AI sector, particularly after US-based Anthropic withdrew its Fable and Mythos models last month due to orders from the US government, citing security concerns, reported Reuters.

Moonshot claims that Kimi K3 is the first open-weight AI model to approach the 3 trillion-parameter mark.

According to the company, the new model is designed to handle advanced reasoning tasks, extended coding projects, and complex knowledge work.

Kimi K3 features a context window of one million tokens, a capability that allows it to analyse and retain far more information than many previous models in a single prompt.

Unlike proprietary models, open-weight AI systems can be downloaded, operated, and modified by users.

This approach is positioned as a key differentiator, as Moonshot and other Chinese developers, such as Z.ai and MiniMax, are introducing increasingly capable models at reduced costs. These developments are accelerating China’s competition with US AI firms.

Moonshot stated that “Kimi K3 performed competitively with Fable 5 (with fallback) and substantially outperformed Anthropic’s Opus 4.8, GPT 5.6 Sol, and GPT 5.5” when tested for GPU kernel optimisation.

This term applies to methods that aim to maximise efficiency and lower response times in AI model computations.

The company also reported that Kimi K3 scored highly in several independent benchmarks, including a first-place ranking from Arena.ai for web interface-building and a second overall placement from Vals AI, trailing only Fable 5 and ahead of GPT-5.6 Sol.

The Kimi K3 build incorporates two newly introduced architectural features, Kimi Delta Attention and Attention Residuals, which Moonshot says enhance computing efficiency and support advanced coding with minimal need for ongoing human involvement.

Kimi K3 is already available through several Moonshot’s platforms, with a full technical report and model weights expected to be publicly released by 27 July.

Moonshot, backed by major Chinese technology firms such as Alibaba and Tencent, has stated that it is working with partners and open-source communities to facilitate the integration and rollout of Kimi K3 across broader AI ecosystems.

In May, Moonshot AI raised around $2bn in new funding, pushing its valuation above $20bn.