Introducing Claude Opus 5.5
Anthropic, Tuesday, September 22nd, 2026
Anthropic launched Claude Opus 5.5, matching Claude Fable 5.1 performance on agentic coding while using 40% less compute.
Anthropic introduced Claude Opus 5.5, the first model in its new 5.5 family, delivering frontier-level agentic coding results while consuming roughly 40% less compute than prior models.
The release also posts improved scores on Anthropic's automated behavioral safety audits compared with earlier models.
Opus 5.5 offers clearer, more structured writing and is now available across all major Claude platforms.
Anthropic added specialized safeguards for high-risk domains such as cybersecurity and biology research.