Microsoft adds Anthropic’s AI to Copilot

Microsoft is leaning into its new partnership with OpenAI’s chief rival, Anthropic. Starting Wednesday, the software giant will incorporate Anthropic’s AI models into its AI assistant Copilot, which has previously been fueled mainly by OpenAI.  

The deal signals yet another step toward the slow disentangling between the erstwhile exclusive partners, and comes a couple of weeks after Microsoft inked a deal to use Anthropic’s AI in Office 365 apps like Word, Excel, and Outlook.  

Copilot business users will be able to choose between OpenAI’s deep reasoning models and Anthropic’s Claude Opus 4.1 and Claude Sonnet 4 for help with certain tasks, like complex researching and help building custom AI tools and enterprise-grade agents. Opus 4.1 is designed for complex reasoning, coding, and deep architecture planning, whereas Sonnet 4 is better for routine development tasks, large-scale data processing, and content generation.