Claude Sonnet 4.5

Claude Sonnet 4.5

Claude Sonnet 4.5 is a cutting-edge AI model designed to excel in coding, reasoning, and complex problem-solving. It is the latest in a series of advanced AI models from Anthropic, aimed at enhancing productivity and efficiency across various professional fields. This model is particularly strong in building complex agents, using computers effectively, and demonstrating substantial improvements in reasoning and math.

Benefits

Claude Sonnet 4.5 offers several key advantages:

• State-of-the-Art Coding: It leads in real-world software coding abilities, maintaining focus for over 30 hours on complex, multi-step tasks.
• Improved Reasoning and Math: The model shows significant gains in reasoning and math capabilities, making it highly effective for tasks requiring logical thinking.
• Enhanced Computer Use: It excels in using computers, with a 61.4% lead on the OSWorld benchmark, which tests AI models on real-world computer tasks.
• Domain-Specific Knowledge: Experts in finance, law, medicine, and STEM fields have noted dramatic improvements in domain-specific knowledge and reasoning compared to older models.
• Agentic Capabilities: The model can handle complex, codebase-spanning tasks better, making it a valuable tool for developers and professionals.
• Safety and Alignment: Claude Sonnet 4.5 is the most aligned frontier model yet, with substantial improvements in behavior, reducing concerning behaviors like sycophancy, deception, and power-seeking.

Use Cases

Claude Sonnet 4.5 can be used in various scenarios, including:

• Software Development: It assists developers in coding, debugging, and architecture, enhancing development velocity.
• Financial Analysis: It delivers investment-grade insights for complex financial analysis tasks, reducing the need for human review.
• Legal Research: It excels in complex litigation tasks, such as analyzing briefing cycles and conducting research to synthesize first drafts of opinions.
• Cybersecurity: It helps in generating creative attack scenarios, strengthening defenses across various domains.
• Creative Design: It improves design tools like Figma Make, making it easier to prompt and iterate, and creating functional prototypes.
• Agent Building: The Claude Agent SDK allows developers to build their own agents using the same infrastructure that powers Claude Code.

Pricing

Claude Sonnet 4.5 is available at the same pricing as Claude Sonnet 4, which is $3 per million tokens for input and $15 per million tokens for output. This pricing structure makes it accessible for a wide range of users and applications.

Vibes

Early customers have shared their positive experiences with Claude Sonnet 4.5:

• Developers: They have noted state-of-the-art coding performance, significant improvements on longer horizon tasks, and enhanced multi-step reasoning and code comprehension.
• Security Teams: They have observed a 44% reduction in average vulnerability intake time and a 25% improvement in accuracy.
• Legal Professionals: They have found the model to be state-of-the-art on complex litigation tasks, such as analyzing briefing cycles and creating detailed summary judgment analysis.
• Design Teams: They have seen noticeable improvements in design tools, making it easier to prompt and iterate, and creating functional prototypes.
• Financial Analysts: They have found the model to deliver investment-grade insights that require less human review.

Additional Information

Claude Sonnet 4.5 is available everywhere today. Developers can use it via the API with the identifierclaude-sonnet-4-5. The model is also integrated into various products, including the Claude Agent SDK, which provides the infrastructure to build powerful AI agents. Additionally, a temporary research preview called "Imagine with Claude" is available to Max subscribers, showcasing the model's capabilities in generating software on the fly.

For complete technical details and evaluation results, users can refer to the official documentation and research posts provided by Anthropic.