Claude Haiku 5.5 lands at #27 in Agent Arena on a budget

Anthropic’s newest small model just took a seat on one of AI’s more demanding leaderboards. Claude Haiku 5.5 (High) ranks #27 overall in arena.ai’s Agent Arena, and it gets there while costing less per task than the models that came before it. What Anthropic shipped Claude Haiku 5.5 was released on October 7, 2026. Anthropic pitches it as the cheapest, fastest and most capable small model in the Claude 5.5 family. That family has a clear pecking order. Opus 5.5 and Sonnet 5.5 are the heavier models. Haiku 5.5 is the lighter sibling aimed at high-volume, cost-sensitive jobs. Anthropic targets the model at agentic work. That covers database queries, coding workflows, automation and customer support. The biggest structural upgrade is memory. Haiku 5.5 carries a 1M-token context window, up from the 200k window on Haiku 4.5. The model also supports browser tools and subagent delegation. Subagent delegation lets one model hand pieces of a task to other model instances. The leaderboard and the price tag Agent Arena evaluates models on real-world, long-horizon tasks. Those are multi-step jobs where a model has to stay on track over many actions, not just ace a single prompt. Haiku 5.5 (Hig...