Moonshot Kimi K3 Tops Epoch ECI Open-Weight Ranking, Claims First in 3D Design
Moonshot's Kimi K3 model has become the top-ranked open-weight system on the Epoch Capabilities Index (ECI), setting a new record on a benchmark that blends dozens of tests into a single score. The result places the model ahead of leading closed-source competitors in standardized evaluations.
The model also claimed first place on a 3D design benchmark with an Elo of 1450 and ranked second on the AA-Briefcase agentic knowledge work platform, trailing only Fable 5. Independent analysis notes the model carries a higher cost per task and processes queries slower than rivals. The firm plans to open-source the model's weights in late July, which would grant it the second spot on the agent benchmark.
From the sources (25 posts)
@designarenaBREAKING: Kimi K3 by @Kimi_Moonshot is officially 1st on Frontend Web App Arena by DesignArena With an Elo of 1326, this open-weight model leads the way, ahead of Fable 5, Sonnet 5, and Opus 4.8 by @AnthropicAI Huge congrats to the @Kimi
@kimi_moonshotRT @DesignArena: BREAKING: Kimi K3 by @Kimi_Moonshot is officially 1st on Frontend Web App Arena by DesignArena With an Elo of 1326, this…
@crystalsssupKimi is #1 in Design Arena, a benchmark for frontend website-building capabilities.
@arenaExciting update: Kimi K3 has landed at #4 on the Agent Arena leaderboard, matching Claude Opus 4.8 and GPT-5.6 Sol. If Kimi K3's weights are released on schedule by July 27, it will become the #1 open-weight model. This release marks a maj
@arenaKimi K3 ranks #4 overall (+9.6%) - #1 Confirmed Task Success (+14.4%) - #3 Praise vs. Complaint (+20.6%) - #4 Tool Hallucination (+1.1%) - #14 Steerability (+5.6%) - #17 Bash Recovery (+6.4%)
@scaling01RT @arena: Exciting update: Kimi K3 has landed at #4 on the Agent Arena leaderboard, matching Claude Opus 4.8 and GPT-5.6 Sol. If Kimi K3's…
@kimi_moonshotRT @arena: Exciting update: Kimi K3 has landed at #4 on the Agent Arena leaderboard, matching Claude Opus 4.8 and GPT-5.6 Sol. If Kimi K3's…
@rohanpaul_aiKimi K3 is ahead of Claude Feble 5 again. Has taken the top spot on DesignArena's Frontend Web App benchmark. On DesignArena bench, AI models receive the same app-building prompt, produce competing interfaces, and users vote for the bette
@epochairesearchMoonshot's Kimi K3 scores 156 on the Epoch Capabilities Index (ECI), setting a new open-weights record. This places it between Opus 4.6, and GPT 5.4, which released in February and March 2026 respectively, and just ahead of GPT 5.6 Luna. ht
@scaling01RT @EpochAIResearch: Moonshot's Kimi K3 scores 156 on the Epoch Capabilities Index (ECI), setting a new open-weights record. This places it…
@teortaxestexKimi K3 scores 5'11 3/4" on Epoch Capabilities index, ahead of GPT 5.6 Luna at 5.11" GPT 5.6 Terra (Gigachad) reigns supreme at 6' (actually 155.6 vs 155.3 vs 158.4) @scaling01 takes the W
@zacharynadoRT @peterwildeford: Kimi K3 is exactly the level of capability you would predict it to have given the long-term 2 year trend of Chinese AI…
@kimi_moonshotRT @DesignArena: BREAKING: Kimi K3 by @Kimi_Moonshot is 1st overall on 3D Design with an Elo of 1450. This is a 6 position and 108 Elo jum…
@crystalsssupKimi K3 is #1 in 3D design arena
@teortaxestexThis is absurdly impressive. BrokenArXiv is *hard* for LLMs and OpenAI focused on such problems hard and holds a commanding lead. Kimi is not a frontend slop machine, it's a generalist proto-AGI (though same can be said of Meta, congrats) h
@scaling01my prediction for GPT-6's ECI is 166.5 (given that it's released at the end of august) so roughly ~10 ECI points higher than Kimi-K3 depending on which trendline you take this implies US frontier labs are ahead 8.2 - 10.9 months
@teortaxestexI don't much like routing but it seems it's starting to work
@artificialanlysKimi K3 is second only to Fable 5 on AA-Briefcase, our agentic knowledge work benchmark, but costs more than Opus 4.8 to run while averaging nearly an hour per task Last week @Kimi_Moonshot released Kimi K3, a 2.8T parameter model that sco
@artificialanlysAA-Briefcase measures model performance across three dimensions: binary rubric checks for ground-truth correctness, pairwise grading on analytical quality, and pairwise grading on presentation quality. The AA-Briefcase Elo is a single metri
@artificialanlysKimi K3’s frontier performance comes at a high Cost per Task. Its average Cost per Task of $10.57 is one of the highest recorded, below Claude Sonnet 5 (max, $14.43) and Claude Fable 5 ($22.30). Compared to Kimi K3, GPT-5.6 Sol (max) trails
@artificialanlysKimi K3 has an average Time per AA-Briefcase Task of 56.4 minutes. This is driven by a high number of turns, as well as higher output token use and lower speeds using the first party Kimi API. Kimi K3 uses 120k output tokens per task and 83
@kimi_moonshotRT @ArtificialAnlys: Kimi K3 is second only to Fable 5 on AA-Briefcase, our agentic knowledge work benchmark, but costs more than Opus 4.8…
@rohanpaul_aiMoonshot's Kimi K3 became strongest open-weights model ever measured on Epoch Capabilities Index (ECI). ECI blends dozens of separate benchmarks into a single score, so one benchmaxxed test result can't distort the ranking the way it does
@ylecunRT @JitendraMalikCV: Highly performant open weights frontier models such as Kimi are a competitive threat to OpenAI & Anthropic, but probab…
@rohanpaul_aiKimi K3 just grabbed another crown. 1st overall on 3D Design with an Elo of 1450.