On Monday, Anthropic launched a new frontier model called Claude Sonnet 4.5, which it claims offers state-of-the-art performance on coding benchmarks. The company says Claude Sonnet 4.5 is capable of building “production-ready” applications, rather than just prototypes, representing a leap in reliability from previous AI models.
Claude Sonnet 4.5 will be available via the Claude API and in the Claude chatbot. The pricing for developers is the same as Claude Sonnet 4: $3 per million input tokens (roughly 750,000 words, or more than the entire “Lord of the Rings” series) and $15 per million output tokens.
In the last year, Anthropic’s AI models have emerged as a favorite among developers and enterprises, in large part due to their strong performance on software engineering tasks. Apple and Meta reportedly use Claude AI models internally, and Anthropic has made a significant business selling API access to AI coding applications such as Cursor, Windsurf, and Replit. Recently, OpenAI’s GPT-5 has challenged Anthropic’s dominance in the space, outperforming Claude models on a variety of coding benchmarks.
Anthropic says Claude Sonnet 4.5 offers industry-leading performance on several coding benchmarks, including SWE-Bench Verified. However, Anthropic AI researcher David Hershey tells TechCrunch that it is hard to capture Claude Sonnet 4.5’s performance on benchmarks alone.
