Claude Opus 5.5

Overview

First model in the Claude 5.5 family, released September 22, 2026 for long-running agentic coding and knowledge work. Anthropic says it performs at Claude Fable 5.1 level on most work, costs 40% less than Opus 5 on typical workloads, generates output more than 30% faster, and is priced at $4 per million input tokens and $20 per million output tokens, with cache reads at $0.20. Deployed with Fable-class biology and cybersecurity safeguards; model ID claude-opus-5-5.

Generally available September 22, 2026 on the Claude API, Amazon Bedrock, Google Cloud and Microsoft Foundry. External pre-release evaluators included Frontier Design and METR. Sonnet 5.5 and Haiku 5.5 are scheduled to follow in the coming weeks.