Microsoft is bringing Anthropic’s Claude Sonnet 4 and Claude Opus 4.1 AI models to its Microsoft 365 Copilot today. It’s a big move that expands model choice beyond just OpenAI’s range of models in Microsoft 365 Copilot, and it will allow Microsoft’s customers to access Anthropic models in Researcher and Microsoft Copilot Studio.
“Copilot will continue to be powered by OpenAI’s latest models, and now our customers will have the flexibility to use Anthropic models too — starting in Researcher or when building agents in Microsoft Copilot Studio,” explains Charles Lamanna, president of Microsoft’s business and industry Copilot team. “The addition of Claude Sonnet 4 and Claude Opus 4.1 advances our commitment to bring the best AI innovation from across the industry to Microsoft 365 Copilot, tuned for work and tailored to your business needs.”
Microsoft’s Researcher agent can now use OpenAI’s deep reasoning models or Anthropic’s Claude Opus 4.1. Researcher users will see a “Try Claude” button at the top of the Microsoft 365 Copilot app that provides access to Opus 4.1 instead of OpenAI’s models. “Once you opt-in, you’ll be able to switch between OpenAI and Anthropic models in Researcher with ease,” Lamanna says.
Claude Sonnet 4 and Claude Opus 4.1 will also be available as model options in Copilot Studio, Microsoft’s platform for building AI agents. “With this launch, you can build, orchestrate, and manage agents powered by Anthropic models for deep reasoning, workflow automation, and flexible agentic tasks,“ Lamanna explains. You’ll also be able to mix which models are used for specific tasks, with options from Anthropic, OpenAI, and other models in Azure’s model catalog.
Claude in Researcher is rolling out today via the Frontier program to Microsoft 365 Copilot licensed customers who decide to opt in. Copilot Studio users can also opt in to get access to Claude.
Interestingly, Anthropic’s AI models will still be hosted on Amazon Web Services, Microsoft’s main cloud rival. Microsoft accesses Claude via the Anthropic API, just like any other developer. Microsoft previously struck a deal with xAI to host Grok 3 models on Azure, so I wouldn’t be surprised to see a similar arrangement with Anthropic’s models on Azure soon.
Microsoft’s announcement of Anthropic models in Microsoft 365 Copilot arrives just a week after the company started favoring Anthropic over OpenAI for Visual Studio Code. GitHub Copilot paid users now “primarily rely on Claude Sonnet 4” when using the Visual Studio Code editor’s new automatic AI model selection.
Reports have also suggested that Microsoft will use Anthropic’s AI models in Excel and PowerPoint soon, after finding they outperformed OpenAI’s own models. “This is just the beginning — we’re committed to delivering model innovation at speed,” Lamanna teases. “Stay tuned: Anthropic models will bring even more powerful experiences to Microsoft 365 Copilot.”
