Is Kimi K3 Really Fable Class?

**Nathaniel Whittemore** (0:00)
Today on the AI Daily Brief, did we actually just get a fable-level open model? The AI Daily Brief is a daily podcast and video about the most important news and discussions in AI.
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All right, friends, well, today we are talking about Kimi K3.
The month of models continues, and today we're going to try to figure out just how significant this one is. At first glance, there are some very significant and bold claims being thrown around, but we're going to unpack what's real, what's not, and what the implications are.
To understand this or frankly, any frontier Chinese model, you have to put it in the context of the way that the US market sees the AI race. Since we're coming to the end of the World Cup, let me plumb for a soccer analogy. When it comes to our lead on China in terms of advanced models, we very much have one to zero type of energy. What I mean by that is that there's no doubt that we're in the lead, but the score line is not something that anyone is particularly comfortable with. The US tends to act like it can feel China coming up on our heels, pressing their advantages and trying to find the equalizer. In other words, despite being in the lead, it can sometimes feel like we're the ones hanging on. And by the way, for any of you Three Lions fans out there, I am so sorry to use this analogy in this particularly difficult moment. In any case, you can see examples of this feeling of China nipping out our heels spread throughout the last couple of years. The best example, of course, was when DeepSeek R1 was released, and it ripped hundreds of billions of dollars of market cap off some of the leading companies, including NVIDIA, which had the biggest one-day fall in dollar terms in stock history. And yet that DeepSeek moment set the tone for all the future quote-unquote DeepSeek moments that would come in more ways than one. What I mean by that is that not only was it a moment where the market freaked out about China having caught up or even exceeded US capabilities, reacting quite severely in market terms, but it was also just pretty meaningfully overblown. It's not that DeepSeek R1 wasn't impressive, but a big part of the reason that it seemed so impressive was that it was democratizing access to a technology that had thus far been locked behind a paywall when it came to companies like OpenAI.
Model itself was actually still pretty meaningfully behind what leading Western labs were doing, but that didn't change its ability to create some pretty significant psychological scars. Now, ever since then, we have been having many DeepSeek moments at a fairly regular clip. The most recent one came when Fable 5 was locked down as per government order, when Z.AI's GLM 5.2 came out leading to not only positive reviews on Twitter, but also this piece from the Wall Street Journal, which was printed and slapped on desks all over Washington DC.
The article was called China Has Matched Anthropic in Cybersecurity, Resetting AI Race, and as we discussed a lot then, was once again another example of the narrative being fairly overblown, but continuing to be persistent as something the US was worried about.
For the last month, really ever since Fable 5 was released, there have been debates around how long it will take for Chinese companies to have a Fable 5 class model. In the middle of June, Elon Musk predicted Q1, to which the founder of ZAI responded, won't take that long. And so that was the setup coming into the announcement of Kimi K3.
Now, Moonshot's Kimi models have been some of the most popular when it comes to Western users using models from Chinese labs. In fact, as we've been discussing fine tunes of open models like Cursor's Composer 2.5, they tend to be built around a Kimi base. On Wednesday, the Kimi K3 teaser started coming in a serious way. AI leaker Leo Synthwave wrote, I think Kimi K3 is going to shock some of the Chinese or eight months behind the Western frontier people.
And then on Thursday, we actually got the model. Let's talk first about the specs. K3 is a 2.8 trillion parameter model, placing it in a class of its own when it comes to open models. Until now, only a small handful of open models were even in the trillion parameter class, beginning with the first version of Kimi K2 last summer. DeepSeq v4 Pro released this April is a 1.6 t model, Xiaomi's Mimo v2.5 Pro is a 1 t model, and Thinking Machine's Inkling model released this week is just shy of 1 trillion. And that's it. GLM 5.2 from ZAI, the model that got all that bluster that we were just talking about, was only a 744b model. Now, proprietary models don't publish their parameter counts, but K3 is likely to be around the same size or maybe a little bit larger than Opus 4.8, but certainly not as big as Fable. In other words, this is a scale of model pre-training that we haven't seen demonstrated by the Chinese labs before. As for features, Kimi K3 supports a million-token context window and native image inputs alongside text. It uses a mixture of experts' architecture which has become standard for both open-source and proprietary models since it was introduced by DeepSeq. And the benchmarks? Well, the benchmarks look incredibly strong. Close to a match for, and in some cases exceeding, Fable 5 and GBT 5.6 sold. On coding benchmark DeepSui, K3 scored 67.5, which put it 8.5 points ahead of Opus 4.8 and a half point ahead of GBT 5.5.