Claude Opus 5.5 (High) beats prior Opus 5 variants at 40–56% lower cost

Arena.ai ranks Claude Opus 5.5 (High) No. 2 in Agent Arena and says it improves on both earlier Opus 5 variants. The median cost is $1.31 per task, with a +12.15% net improvement, at 40–56% lower cost than those variants.

Arena.ai lists Opus 5 (Max) at a $2.98 median cost per task and +9.58% net improvement, and Opus 5 (High) at $2.17 and +9.47%. Opus 5.5 (High) is 56% below the Max median and 40% below the High median.