China's Kimi K3 goes open-source, breaks new ground with Fable-tier results
'K3 stands as Moonshot AI’s most powerful open-source coding model to date,' said Moonshot AI
Published July 17, 2026
China’s Kimi K3 Moonshot AI model has broken new ground, with its release on Thursday, July 16, 2026.
Moonshot AI has rolled out an artificial intelligence model, "Kimi K3," claiming it has surpassed some of the elite-tier U.S. systems.
Chinese AI company Moonshot said on Friday, July 17, that it is aiming to fully open-source the model, called Kimi K3, by the end of July, with free download and customization.
Kimi K3, with a reported 2.8 trillion parameters, makes it the largest open-source large language model (LLM), according to Moonshot AI.
For the unversed, parameters are the internal variables the AI model learns during training.
The more parameters, the more reliable it is to manage more complex reasoning. As of now, DeepSeek V4 has 1.6 trillion parameters.
In a statement released on July 16, Moonshot AI said, “K3 stands as Moonshot AI’s most powerful open-source coding model to date.”
“Operating with minimal human oversight, it can sustain long engineering sessions, navigate massive repositories, and orchestrate terminal tools,” the statement reads.
Why does the Kimi K3 matter?
The Chinese AI company Moonshot AI, in its release, claimed that K3 performed “competitively” with Anthropic’s Fable 5 and “substantially outperformed” Anthropic’s Opus 4.8, OpenAI’s GPT 5.6 Sol and GPT 5.5.
This claim has rung alarms in Silicon Valley, as China has taken one step further in challenging America’s dominance in advanced artificial intelligence.
Anthropic’s Mythos 5 model, on which Fable is designed, is widely reported to be the most capable model in existence to date when carrying out cyber-related tasks.
Although Mythos' 5 access is only limited to fewer enterprises under Anthropic's Glasswing program.
In the days to come, if the K3’s performance claims stand, the model will challenge Anthropic’s and OpenAI’s market dominance.
Kimi K3 can be accessed via Kimi Work, Kimi Code, Kimi API, and Kimi.com, with open-source starting on July 27.
