Anthropic launches Claude Opus 5.5: Fable 5.1-level performance at ~40% lower cost

The Decoder · rss · 2026-09-23

Anthropic has launched Claude Opus 5.5, the first of a new generation. The company says it matches Claude Fable 5.1 on most tasks while costing roughly 40% less to run than Opus 5. Its benchmarks also place it ahead of OpenAI's GPT-6 Astra on most tasks at a significantly lower price, and Anthropic promises the new model sounds less "Claudish." Sonnet 5.5 and Haiku 5.5 are expected in the coming weeks.

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