Claude 3.7 Sonnet Review: The Best Coding and Analysis AI in 2026
Anthropic released Claude 3.7 Sonnet in February 2026 with a bold claim: state-of-the-art performance on coding benchmarks while maintaining the safety and interpretability properties Anthropic is known for. After six weeks of daily use across real production engineering tasks, here is our honest verdict.
Where It Excels
Claude 3.7 Sonnet is the best model we have tested for two specific tasks: complex multi-file code refactoring and long-document analysis. When given a 50,000-line TypeScript codebase and asked to extract all database queries and propose a data access layer abstraction, it produced a coherent, well-documented design proposal in under 60 seconds — something GPT-4o struggled to do without fragmentation.
For legal and financial document analysis, it maintains context across 200-page documents more reliably than any competing model. Its tendency to acknowledge uncertainty when the text is ambiguous makes it safer for high-stakes extraction tasks.