Claude Sonnet 5's Price Cut Is the Real Story, Not the Benchmarks
Anthropic's Claude Sonnet 5 launched on June 30 with the kind of benchmark chart every model release ships with these days: 63.2% on SWE-bench Pro, up from Sonnet 4.6's 58.1%, closing in on flagship Opus 4.8's 69.2%. On Humanity's Last Exam, it hits 57.4% with tool use, essentially matching Opus 4.8's 57.9%. On GDPval-AA v2, a knowledge-work benchmark, Sonnet 5 actually edges past Opus 4.8, 1,618 to 1,615. Those numbers are real and worth noting. But they're not the interesting part. The interesting part is the price tag attached to them. Sonnet 5 is shipping at an introductory $2 per million input tokens and $10 per million output tokens through August 31, dropping to a standard $3/$15 after that. For a model landing within a few points of a frontier-tier system on agentic coding and reasoning benchmarks, that's a meaningfully different cost structure than what "near-frontier performance" has historically demanded. Why this matters more than th...