AI Models
Claude Sonnet 5 Reviewed: Opus-Class Autonomy at a Sonnet Price
Anthropic's new workhorse is its most agentic Sonnet yet, sold as close to Opus 4.8 for a fraction of the cost. The fine print sits in two places: the coding benchmark it did not publish, and the tokenizer change that quietly trims the discount.

Claude Sonnet 5 lands as the most capable model you can actually deploy at scale today, pitched as Opus-class autonomy at a Sonnet price. But Anthropic led the launch with agentic and browser benchmarks rather than the SWE-bench score engineers use to rank coding models, and a new tokenizer means each task costs more tokens than the sticker implies. A review of what is new, what it costs, and whether you still need Opus.







