Chinese startup launches world's largest open AI model 'Kimi K3', nears Fable and GPT-5.6 level performance

Published 17 July 2026 · tech

China is back at it again. Chinese AI startup Moonshot has unveiled Kimi K3, claiming it to be the largest open-weight AI model with 2.8

China is back at it again. Chinese AI startup Moonshot has unveiled Kimi K3, claiming it to be the largest open-weight AI model with 2.8 trillion parameters. As per the AI startup, Kimi K3 is a big improvement compared to previous versions, and now can match if not outperform the most advanced models from the US, including Claude Fable and GPT 5.6. Read Full Story The Kimi K3 announcement comes at a time when the US is considering restricting advanced AI models made by US companies over fears of potential misuse. The US had temporarily blocked Claude Fable 5, and asked for a limited release of GPT-5.6. What is Kimi K3? Kimi K3 is an open-weight AI model. This means that anyone can freely download the model and run it locally on their device, making it cheaper than close-weight models like Claude Fable. To give you some context, Fable and GPT-5.6 can only be accessed via the cloud, and cost higher to run due to token pricing. But open-weight models have existed for some time now, including Moonshot’s older models. What makes Kimi K3 different is how large it is. The model is trained on 2.8 trillion parameters – the more parameters, the better a model can perform.

For context, as per reports, Anthropic’s Claude Opus 4.8 model was likely trained somewhere around 2 billion parameters. How good is Kimi K3? As part of the announcement, Moonshot shared benchmark results, comparing Kimi K3 to rival models. The startup said that Kimi K3 “performed competitively with Fable 5” and “substantially outperformed” Opus 4.8, GPT 5.6 Sol and GPT 5.5 in GPU kernel optimisation, a term used for methods that improve hardware use and reduce latency. Third-party evaluations also placed the model close to top US systems. Arena AI ranked Kimi K3 first in its Frontend Code Arena. Arena AI confirmed that the AI model had managed to surpass Claude Fable 5, and jumped from 18th place for Kimi K2.6. Kimi K3 even outperforms Claude Fable and GPT-5.6 in certain benchmarks. Vals AI placed Kimi K3 second overall behind Fable 5 and ahead of GPT-5.6 Sol, while Artificial Analysis said its performance was comparable to GPT-5.5 and Claude Opus 4.8, especially on complex multi-step tasks. That is to say, that while Kimi K3 is not the most advanced AI model out there, it has closed the gap to frontier models from US companies. It is also the most-advanced open-weight model at the moment. Moonshot says that Kimi K3 has a one million-token context window, supports native multimodal use, and is built for advanced reasoning, long-horizon coding and knowledge work, with the ability to handle long engineering sessions with limited human supervision.