Anthropic just dropped Claude Sonnet 5, and it might be the most interesting model they have released this year. It delivers performance close to Opus 4.8 on coding and agentic tasks at roughly half the price.
Sonnet 5 is the default model for Free and Pro users starting today. It is also available in Claude Code for Pro subscribers, through the API as claude-sonnet-5, and on Managed Agents. It carries a 1 million token context window.
What makes Sonnet 5 different
The headline is that Sonnet 5 narrows the gap between Anthropic’s Sonnet and Opus tiers significantly. Anthropic’s own benchmarks show it landing close to Opus 4.8 on reasoning, tool use, coding, and knowledge work while costing much less.
Introductory pricing runs through August 31, 2026: $2 per million input tokens and $10 per million output tokens. After that it settles at $3 and $15 respectively. For comparison, Opus 4.8 runs at $15/$75.
Early access partners are reporting the same thing: Sonnet 5 finishes complex multi-step tasks that would have stalled on previous Sonnet models. Testers described it checking its own output unprompted, writing reproducing tests before fixing bugs, and shipping clean multi-step changes in a single pass.
Safety picture
Anthropic’s safety assessments show Sonnet 5 has a lower overall rate of undesirable behaviors than Sonnet 4.6, making it safer to use in agentic contexts. Notably, it has a much lower ability to perform cybersecurity tasks than current Opus models, which is a deliberate safety consideration.
Why this matters
The agentic AI era started with Sonnet-class models (3.5, 3.6, 3.7) that first showed real coding and tool use skills. More recently, the biggest agentic gains have been in Opus-class models. Sonnet 5 brings those capabilities back down to the Sonnet price tier.
For anyone building on Claude Code or the API, this is the model to test first. It is likely to become the default recommendation for agentic coding workflows that do not need the absolute ceiling of Opus 4.8.
Anthropic’s timing is interesting given the regulatory pressure they have been facing. The government restrictions on Fable 5 and the upcoming Claude deadlines make this a strategic release — a capable model at a price point that keeps developer adoption high while navigating export controls.
