Claude Fable 5.2 Tops Agent Arena with a Net Improvement of +30.4%
Arena's Agent Arena leaderboard shows that Anthropic's Claude Fable 5.2 (Max) ranks first with a +30.4% net improvement, about 1.6 times that of the second-place Opus 5.5 (+19.5%), based on data from 4.7k real agent sessions. Compared with Fable 5.1, its ranking rose from 5th to 1st, its median per-task cost fell from $7.7 to $7.3, and its API price dropped from $10/$50 to $8/$40 per million tokens. The model ranks first in all three categories—Code, Work, and Chat—corresponding to +34%, +31%, and +27%.
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The leaderboard provides a comparison of Fable 5.2 with models such as 5.1 and Opus 5.5 in terms of net improvement and per-task cost, which can be used to assess changes in cost-effectiveness.
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View original postIntroducing Claude Fable 5.2 and Claude Mythos 5.2, designed to tackle the most daunting technical challenges. They’re capable collaborators on ambitious projects in many fields, and show improvements in areas like coding, reasoning, and vision. https://t.co/jP0AutLxXb
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Introducing Claude Fable 5.2 and Claude Mythos 5.2, designed to tackle the most daunting technical challenges. They’re capable collaborators on ambitious projects in many fields, and show improvements in areas like coding, reasoning, and vision. https://t.co/jP0AutLxXb
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Big news: Claude Fable 5.2 (Max) by @AnthropicAI takes #1 in Agent Arena with an unprecedented lead: +30.4% net improvement, about 1.6x the #2 model Opus-5.5, across 4.7k real-world agentic sessions from our global community. It's also #1 in Code, Chat and Work.
A major leap over Claude Fable 5.1 (Max) - Rank: #5 → #1, Net improvement: +14.8% → +30.4% - Median cost per task: $7.7 → $7.3 (6% lower). The API pricing $10/$50 → $8/$40 per million input/output tokens (20% lower)
vs. The Frontiers - #1 Claude Fable 5.1 (Max): +30.4% | $7.3/task - #2 Claude Opus 5.5 (Max):+19.5%) | $5.5/task - #3 Gemini 4 Carbon (High):+17.0%) | $1.5/task - #6 GPT-6-Astra (Max): +14.5% | $6.0/task
Breaking down performance across signals: Fable 5.2 improves over 5.1 across all four reported signals, with particularly large gains in user satisfaction and steerability. - #1 Praise vs. Complaint , +73%, biggest jump vs +41% the next model. - #1 Steerability: +33% - #1 Confirmed Success: +22% - #3 Bash Reliability: +14%
#1 across all major categories - #1 Code: +34% - #1 Work: +31% - #1 Chat: +27% - Versus Fable 5.1: Code #6 → #1 (+19.8 %), Work #4 → #1 (+15.8 %), Chat #6 → #1 (+12.0%).
Huge congrats to the @AnthropicAI team on this incredible release!