Claude Sonnet 5.5 Matches Opus at Half the Cost

Why this matters

For teams building on Claude, the math just changed. If Sonnet 5.5 genuinely closes most of the gap to Opus 5.5 while running 30 percent faster and cheaper, the default choice for production coding agents shifts down a tier. That's real money for anyone running high-volume inference, not a marginal optimization. The Terminal-Bench jump from 10.3 percent to 70.6 percent is the number worth sitting with, since it suggests the improvements aren't cosmetic tuning but a genuine leap in how the model handles multi-step agentic tasks, the kind of work most coding assistants still struggle with.

We'd still want to see how these benchmark gains hold up on messier, real-world codebases rather than curated test suites, since Anthropic is the one reporting its own numbers here. But the availability on AWS and Google Cloud from day one matters practically: enterprises already committed to those platforms don't have to wait or negotiate new procurement to try it. Watch whether Opus quietly becomes the niche option, reserved only for the hardest problems, while Sonnet eats the rest of the workload.