The Verge reported the launch on September 28, 2026, citing Anthropic.
According to the report, Anthropic says Sonnet 5.5 is 30 percent faster and 30 percent cheaper to use than Claude Sonnet 5. The model also includes stricter cybersecurity safeguards intended to reduce misuse, similar to safeguards introduced with Claude Opus 5.5.
The report does not provide API token prices, benchmark scores, availability details, regional access terms, or a methodology for the stated speed and cost reductions. It also does not establish how those claimed reductions will translate to a particular application or agent workflow.
The information available here is a report of Anthropic's product claims, not an independent performance or security evaluation.