Kimi teases K3.1: Moonshot's official video names its next model — and a mysterious 'Kibitz' on the Arena looks a lot like it

• Who: Moonshot AI, via the official @Kimi_Moonshot account.
• What: A 24-second retro-computer-style teaser video shows ‘Model: Kimi K3.1’ in a Kimi Code terminal, generating complex 3D scene code with Three.js.
• When: Posted October 23, 2026.
• Paper trail: the ‘kimi-k3-1’ identifier appeared in Moonshot's API platform in late September, and in Kimi Code's model-switching configuration on October 21.
• Arena signal: an anonymous model named ‘Kibitz’ appeared on the Arena on October 22; tokenizer evidence and Kimi's arena codename pattern (Kiwido, Kiwire, Kivine → Kibitz) suggest it is K3.1 — unconfirmed by Moonshot.
• Unknown: release date, specifications, pricing, benchmarks and open-weight status — Moonshot has confirmed none of these.

Moonshot AI has stopped being coy. On October 23, the company's official @Kimi_Moonshot account posted a 24-second retro-computer-style teaser showing a Kimi Code terminal writing complex Three.js 3D scene code — with “Model: Kimi K3.1” displayed in the corner of the screen. It is the first time the company has put the K3.1 name in official material, and it lands a month after the identifier first surfaced in Moonshot's API platform in late September.

The clip itself is pure signal and zero substance: a vintage terminal aesthetic, a coding agent doing its thing, a model name in the corner. No release date, no specifications, no pricing, no benchmarks. Moonshot's message is the oldest one in the model business — it's coming — but the fact that Kimi is teasing at all suggests the launch window is near.

The Kibitz mystery

Here's the interesting part: the new model may already be running in public under an alias. On October 22, a day before the teaser, an anonymous model named “Kibitz” quietly appeared on the Arena — and developers immediately started asking whether it was K3.1 in disguise (TestingCatalog).

The evidence is circumstantial but unusually tidy. The model-tracking account @aitrackerbot ran tokenizer tests: when asked to reproduce verbatim 11 special token strings characteristic of the Moonshot family, Kibitz failed across two consecutive rounds — exactly matching the behavior of other Kimi models — while control models from seven other labs reproduced them correctly. Then there's the naming pattern: Kimi K2.5, K2.6 and K3 were previously arena-tested under the codenames Kiwido, Kiwire and Kivine. Kibitz slots neatly into the sequence.

Early tester impressions are strong. One tester pitted Kibitz against models including GPT-6 Astra Max and Claude Opus 5.5 on a single-prompt task — building a 3D voxel courtyard with a pagoda, trees and cherry blossoms from one HTML file — and reported that Kibitz delivered a finished, richly colored result in roughly a third of the time its rival took. That is one tester's account, not a benchmark, but it's the kind of result that made the rumor stick. The Arena's own account added fuel on October 23, posting: “A new model from @Kimi_Moonshot is coming. Stay tuned for where it lands in the Arena.”

The paper trail

The teaser caps a week of leaks. On October 21, screenshots surfaced of a model-switching warning in Kimi Code naming Kimi K3.1, and a day earlier the kimi-k3-1 identifier had been found in Moonshot's API infrastructure. Community watcher Chris claimed the model will release before Tuesday next week as a low-cost, state-of-the-art open-source model — but that remains unverified chatter, not a company statement.

What we still don't know

Almost everything that matters: context length, benchmark scores, pricing, the final feature set, and whether K3.1 ships open-weight like its predecessor. Watchers widely expect open weights — Kimi K3 was open-weight with published weights on Hugging Face — but Moonshot hasn't said. And the Kibitz identification, compelling as the tokenizer evidence is, is still unconfirmed by the company. For now, the facts are these: a name in a corner of a screen, a very fast anonymous model on the Arena, and a launch that looks days — not months — away.