Anthropic releases Claude Sonnet 5.5 with the cyber limits it reserved for its best models

Anthropic released Claude Sonnet 5.5, scoring 70.6% on Terminal-Bench 4.0, a 10.3% improvement over Sonnet 5 and surpassing Opus 5.5’s 66.4% at the same effort level. The model runs more than 30% faster, costs up to 30% less per task, and includes frontier-style cyber safeguards and classifiers that block reasoning extraction. Sonnet 5.5 is priced at $2 per million input tokens and $10 per million output tokens.