Morning Edition · Thursday, October 15, 2026Published at 2:37 AM EDT · New York

Claude Haiku 5.5 Ships at a Tenth of Haiku 4.5's Price as New Research Doubles Hard-Prompt Accuracy for a 0.6B Model After RL Saturates

Anthropic's small model scores 72.4% on OSWorld 2.1 at maximum effort for less than Sonnet 5.5 costs at low effort, while an inverse-reasoning paper shows how to post-train on answer-only data without reasoning traces.

Anthropic released Claude Haiku 5.5 on October 7 and describes it as its fastest and cheapest small model. Pricing reported by Computing for Geeks is $0.10 per million input tokens and $0.50 per million output tokens for prompts under 100,0…