Claude Sonnet 5.5 Matches Opus at Half Price

Sonnet 5.5 makes Opus-class coding capability more economical, but “beats Opus” is a narrow benchmark claim rather than an overall victory.

• –Costs $2/$10 per million input/output tokens versus Opus 5.5’s $4/$20.
• –Terminal-Bench results use different effort settings, so the 70.6% versus 66.4% comparison needs caution.
• –Opus still leads on most benchmarks involving deep reasoning and sustained judgment.
• –Faster generation, fewer tokens per task, and up to 30% lower task costs make Sonnet 5.5 attractive for high-volume coding agents.
• –Cybersecurity safeguards and fallbacks similar to Opus expand deployment options while limiting higher-risk capabilities.