Microsoft to add Anthropic AI to Office 365, alongside OpenAI

Microsoft is preparing to add artificial intelligence models from Anthropic to some features in its Office 365 productivity suite, a shift that will see Anthropic technology used alongside OpenAI models in Word, Excel, Outlook and PowerPoint, according to people involved in the project and a report published this week. The company plans to pay for access to Anthropic’s models and is expected to announce the change in the coming weeks, sources said.

The move follows internal testing that found Anthropic’s latest model, Claude Sonnet 4, outperformed OpenAI’s models on certain tasks such as automating complex spreadsheet functions and generating aesthetically pleasing PowerPoint decks, developers involved in the effort told reporters. Microsoft will obtain the Anthropic models through a cloud provider and will pay to host and run them, a setup that marks a departure from its long reliance on OpenAI for Copilot features in Office 365.

A Microsoft spokesperson said the company remains committed to its long term partnership with OpenAI and called OpenAI a continuing partner for frontier models. The spokesperson did not comment on timing or contract details. Anthropic and OpenAI did...