Anthropic Launches Claude Sonnet5 as Strongest Sonnet Yet
AGI Hunt · wechat · 2026-07-01
Anthropic released Claude Sonnet5, positioning it as the "strongest Sonnet yet" rather than the overall strongest Claude. Its coding and agentic capabilities approach or match Opus4.8; ArtificialAnalysis tests show it matches or exceeds Opus4.8 in agentic knowledge work (AA-Briefcase Elo 1393 vs 1353), but it still trails Opus and Fable in heavy reasoning benchmarks like Humanity's Last Exam and GPQA Diamond.
Available across all platforms including API, Claude Code, Managed Agents, and the Claude platform, with Sonnet5 now the default model for Pro users in Claude Code. Standard pricing is $3 per million input tokens and $15 per million output tokens, with a promo at $2/$10 until September 1. However, due to consuming about 40% more tokens than Sonnet4.6, actual cost per task ($2.29) surpasses Opus4.8 ($1.80) and is 4.75x that of GLM-5.2 ($0.48).
It retains the 1-million-token context and supports five effort levels: low/medium/high/xhigh/max (the first time xhigh is added to the Sonnet series).
Related event: Claude Sonnet 5 Now Available to Everyone(2 posts)→
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