DeepSeek-V4.1-Flash-20261017 Tops the Agent Arena Open-Model Leaderboard
Arena.ai says DeepSeek-V4.1-Flash-20261017 (Max) has become the top-ranked open-source model in Agent Arena, ranking 11th overall, with a net improvement of 5.1% across more than 7.5K real sessions. The model's median cost per task is $0.20, roughly 37% of GPT-6.1 Sol's improvement margin and 27% of its cost; it ranks first among open-source models on all four signals—Confirmed Success, Praise vs. Complaint, Bash Reliability, and Steerability—and shows no tool-hallucination issues.
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Agent Arena's empirical leaderboard shows that DeepSeek-V4.1-Flash has entered the top ranks at a lower cost, allowing readers to compare the cost-effectiveness of open-source and closed-source models.
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View original postExciting news: DeepSeek-V4.1-Flash-20261017 (Max) by @deepseek_ai is now the #1 open model in Code Arena: WebDev, surpassing Kimi K3 (Max) at 10x lower cost! Highlights: - #1 open model, ahead of Kimi K3 (Max) - #12 overall with 1670 pts, ahead of Claude Opus 5 (High) and within ~10 pts of GPT-6 Sol (Max) - Shifts the Pareto frontier at $0.3/$1.2 per million input/output tokens - +52 pts vs. the previous DeepSeek-V4.1-Flash-20260910 Congrats to the @deepseek_ai team on another strong contribution to the open source ecosystem!
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Exciting news: DeepSeek-V4.1-Flash-20261017 (Max) by @deepseek_ai is now the #1 open model in Code Arena: WebDev, surpassing Kimi K3 (Max) at 10x lower cost! Highlights: - #1 open model, ahead of Kimi K3 (Max) - #12 overall with 1670 pts, ahead of Claude Opus 5 (High) and within ~10 pts of GPT-6 Sol (Max) - Shifts the Pareto frontier at $0.3/$1.2 per million input/output tokens - +52 pts vs. the previous DeepSeek-V4.1-Flash-20260910 Congrats to the @deepseek_ai team on another strong contribution to the open source ecosystem!
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Big news: DeepSeek-V4.1-Flash-20261017 (Max) by @deepseek_ai is now the #1 open model in Agent Arena! It just landed at #11 overall with +5.1% net improvement across +7.5K real-world sessions.
This performance also reshapes the Agent Arena Pareto frontier! All models above V4.1-Flash 20261017 in performance are proprietary at much higher cost. At $0.20 median cost per task, that’s ~37% of GPT-6.1 Sol’s improvement for about 27% of the cost.
By signal, this release achieves: - #8 in Confirmed Success with +11.5% (#1 open) - #11 in Praise vs. Complaint with +5.9% (#1 open) - #12 in Bash Reliability with +5.4% (#1 open) - #13 in Steerability with +2.5% (#1 open) - No issues with Tool Hallucination
Find more info on signals at the link in thread on Agent Arena.
Congrats to the @deepseek_ai team on this release!