Microsoft Favors Anthropic AI Models, Prioritizing Claude Sonnet 4 for GitHub Copilot

Microsoft is adding automatic AI model selection to Visual Studio Code, prioritizing optimal performance. GitHub Copilot free users will see automatic selection between models like Claude Sonnet 4, GPT-5, and GPT-5 mini, while paid users will primarily use Claude Sonnet 4. Internal documents reveal Microsoft is instructing developers to favor Claude Sonnet 4 and is making significant investments in its own AI model cluster. Furthermore, parts of Microsoft 365 Copilot will leverage Anthropic models. Despite a new deal with OpenAI, Microsoft's preference for Anthropic's AI signals a shift in its AI strategy.