Claude Sonnet 5: Cheaper, Powerful AI Agents from Anthropic

Anthropic has launched Claude Sonnet 5, a more powerful and "agentic" version of its midsize model. This new model can make plans, use tools, and run autonomously at a level previously seen only in larger, more expensive models. What's interesting is that Sonnet 5 promises performance close to Opus 4.8, but at a much lower cost. It will be the default model for free and Pro plans. At launch, Sonnet 5 is priced at $2 per million input tokens and $10 per million output tokens until August 31st. This makes it cheaper than Opus 4.8, OpenAI’s GPT-5.5, and Google’s Gemini 3.1 Pro. The new model also shows significant improvements in areas like reasoning, tool use, and software coding compared to its predecessor. For example, it scores 63.2% on agentic coding, close to Opus 4.8’s 69.2%. The bottom line is that Sonnet 5 offers developers a more affordable option for high-quality agentic work, balancing cost and performance.