Microsoft Adds Anthropic AI Models to 365 Copilot, Expanding Beyond OpenAI

Microsoft announced on Wednesday that it is integrating Anthropic’s AI models into its Copilot assistant, marking a strategic move to diversify beyond its close partnership with OpenAI, the maker of ChatGPT.

While OpenAI’s models will continue to power Copilot by default, users will now be able to choose Anthropic’s Claude Sonnet 4 and Claude Opus 4.1 for tasks within Copilot’s “Researcher” tool and when building custom agents in Microsoft Copilot Studio.

Starting this week, users who opt in to test Claude will be able to switch seamlessly between OpenAI and Anthropic models in Researcher, said Charles Lamanna, president of Microsoft’s business and industry Copilot division.

The shift underscores Microsoft’s effort to broaden the foundation of its AI services. Until now, Copilot’s advanced features across apps such as Word and Outlook have relied primarily on OpenAI.

Although Microsoft is OpenAI’s largest investor, the company has also been developing its own models and integrating those from other AI firms. Earlier this year, it announced plans to offer models from Elon Musk’s xAI and Meta Platforms, all hosted within its data centers. Models from China’s DeepSeek have also been added to Microsoft’s Azure cloud platform.

Anthropic’s Claude models, however, are primarily hosted on Amazon Web Services (AWS), a direct competitor to Microsoft Azure, highlighting a rare cross-cloud collaboration.