[AINews] Kimi K3 2.8T-A50B: the largest open model ever released; Opus 4.8-class at Sonnet 5 pricing

Z.ai GLM has been getting a bit too much love recently, so it’s time for Kimi K3 to fight back! It’s hard to put the scale of today’s open model release in perspective, so thankfully Moonshot AI did it for us:

Their vibe reel was entirely edited by Kimi K3 and worth a watch:

You can read SimonW and Arena for standard takes and rankings, none of which will be particularly unexpected given the large size of the model, but this pic best summarizes the K2.5 to K3 jump:

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AI Twitter Recap

Moonshot AI launched Kimi K3 as a frontier-class open-weights model, with official claims that place it near top closed models and above prior open competitors.

Moonshot officially introduced Kimi K3 as “Open Frontier Intelligence” with 2.8T total parameters, 1M-token context, native multimodal input, Kimi Delta Attention (KDA), and Attention Residuals, and said the model is live on Kimi.com, Kimi Work, Kimi Code, and API, with open weights promised by July 27, 2026 @Kimi_Moonshot

Moonshot also highlighted product positioning around long-horizon agentic coding and self-evolving workflows, plus “vision in the loop” coding/game-building workflows that iterate between code and screenshots @Kimi_Moonshot

Before the formal announcement, multiple accounts circulated leaked or app-sourced details that K3 was 2.8T params, calling it the largest open-weight model ever if weights ship as promised @scaling01, @scaling01, @eliebakouch

The official Kimi blog went live later and was widely shared as the primary technical source @Jianlin_S, @scaling01, @Yulun_Du

Moonshot’s own phrasing acknowledged a limitation: despite being highly competitive overall, K3 still has a “noticeable gap in user experience” versus Claude Fable 5 and GPT-5.6 Sol @scaling01

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