Key facts
- Anthropic launched Claude Sonnet 5, a midsize AI model with enhanced agentic capabilities.
- The new model is designed to perform tasks like planning, using tools, and running autonomously at a lower cost than larger models.
- Sonnet 5 is priced at $2 per million input tokens and $10 per million output tokens until August 31, with a subsequent price increase.
- Performance benchmarks show Sonnet 5 nearing Opus 4.8's capabilities in areas like coding and knowledge work, while being more cost-effective.
- Sonnet 5 ships without the restrictions of Fable 5 and Mythos 5, which remain suspended.
Anthropic has launched Claude Sonnet 5, positioning it as a more powerful and agentic version of its midsize language model. The company stated that the new model can plan, utilize tools like browsers and terminals, and operate autonomously, capabilities previously requiring larger and more expensive models. Sonnet 5 is available for Free, Pro, Max, Team, and Enterprise users, as well as through the API. Unlike previous Sonnet launches, this iteration is designed to perform alongside the previous Opus model rather than being a tier below it. Anthropic's evaluations show Sonnet 5 performing nearly on par with Opus 4.8 on the GDPval-AA v2 knowledge-work benchmark and achieving a 63.2% score on the SWE-bench Pro coding benchmark, an improvement over Sonnet 4.6's 58.1%. The introductory pricing of $2 per million input tokens and $10 per million output tokens is effective until August 31, after which it will revert to $3/$15, still significantly lower than Opus 4.8's $5/$25 rate. Sonnet 5 also ships without the restrictions of Fable 5 and Mythos 5, which remain suspended due to a U.S. export control directive. The model uses an updated tokenizer that may increase token consumption for the same input.