Kimi K3.1 Pro Ranks Eighth in WebDev Arena
Arena.ai reported that Kimi K3.1 Pro ranked eighth in the Code Arena: WebDev with 1,692 points, nine places and 37 points above Kimi K3. It also said the model matched Claude Opus-5 (Max) at 70% lower cost. In Agent Arena, Kimi K3.1 Pro (Max) placed 11th after a reported 7.6% net improvement across more than 4,000 sessions, with a six-percentage-point gain over Kimi K3 (Max).
The new Arena results position Kimi K3.1 Pro as a stronger coding and agentic model while reporting lower costs than its predecessor and Claude Opus-5 (Max).
RT Arena.ai Kimi K3.1 Pro (Max) by @Kimi_Moonshot just landed in the Agent Arena at #11 with +7.6% net improvement across +4K real-world agentic sessions from our global community of users. Kimi K3.1 Pro (Max) would be the new #1 open model in the Agent Arena overtaking DeepSeek-v4.1-Flash! Open weights coming soon, stay tuned. Kimi K3.1 Pro (Max) is a +6 percentage pt improvement over Kimi K3 (Max) at +1.6% (#25 -> #11). And with a $1.03 median cost per task in Agent Arena, Kimi K3.1 Pro is 13% less than its previous variant. See its placement just off the Pareto frontier in thread. Across Agent Arena categories, Kimi K3.1 Pro (Max) ranks #8 in Work, #9 in Code, and #10 in Chat. By signal, it’s the strongest in Praise vs. Complaint (implicit sentiment in user reactions) with +19% at #8. Across other signals it landed: - #11 in Steerability (+8.3%) - #15 in Bash Reliability (+8.3%) - #26 in Confirmed Success (+2%) Huge congrats to the @Kimi_Moonshot team on this release!
Arena.ai: Big news: @Kimi_Moonshot is back in the top-4 labs in the Code Arena: WebDev with the release of Kimi K3.1 Pro! This model just landed #8 in the Code Arena: WebDev with 1692 pts, matching Claude Opus-5 (Max) at 70% lower cost. This is a 9 place jump (+37 points) from Kimi K3
#Kimi K3.1 Pro#Kimi K3#Claude Opus-5 (Max)#DeepSeek-v4.1-Flash#Arena.ai#Kimi AI