Claude Opus 5.5 joins the Agent Arena leaderboard

Arena.ai @arenaOriginally posted 2026.09.23

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Claude Opus 5.5 by @AnthropicAI is now in the Agent Arena! Your votes drive the @arena leaderboards, head over and bring your toughest prompts. In Agent Arena, we measure models on millions of real-world, long-horizon agentic tasks from a global community of users. Models can https://t.co/CjPaEZ425p https://t.co/Z8EWBptms3

This post quotes another post: “Anthropic releases Claude Opus 5.5 model”