Claude Opus 5.5 matches Fable 5.1 performance at 60% lower API pricing

Anthropic released Claude Opus 5.5 on September 22, 2026, and priced it below the model it competes with. The model runs at $4 per million input tokens and $20 per million output tokens. That is 20% under Opus 5 and 60% under Fable 5.1, which still bills at $10 and $50. Anthropic says the model […]