Microsoft is preparing to change how artificial intelligence is supplied inside Office 365. According to The Information, the company will add Anthropic’s AI models to its productivity suite, ending years in which OpenAI had exclusive control over generative AI features across Word, Excel, PowerPoint, and Outlook.
The reported shift does not mean Microsoft is walking away from OpenAI. Instead, it points to a more complex phase in enterprise AI, where major platforms may rely on several model providers rather than a single partner for every task.
A second AI supplier for Office 365
Microsoft’s Office 365 suite will soon incorporate AI models from Anthropic alongside existing OpenAI technology, The Information reported. That would make Anthropic a second AI supplier for the productivity products used across Word, Excel, PowerPoint, and Outlook.
The reason, according to the report, is performance. Internal testing reportedly showed that Anthropic’s Claude Sonnet 4 model was stronger at specific Office tasks where OpenAI’s models did not perform as well. The areas singled out were visual design and spreadsheet automation.
Those categories matter because Office AI is not one feature. It spans writing, formatting, calculations, presentations, email, and other workflows. A model that performs well in one part of the suite may not be the strongest fit for another.
Sources familiar with the project cited by The Information stressed that the move is not a negotiating tactic. Anthropic did not immediately respond to Ars Technica’s request for comment.
How Microsoft plans to access Claude
The arrangement is notable because Microsoft will reportedly buy access to Anthropic’s models through Amazon Web Services. That makes the deal more complicated than a simple supplier change.
Amazon Web Services is both a cloud computing rival to Microsoft and one of Anthropic’s major investors. Yet Microsoft is expected to use that route to bring Anthropic’s models into its own productivity products.
The integration is expected to be announced within weeks, according to the report. Subscription pricing for Office’s AI tools is expected to remain unchanged.
For users and businesses, the practical point is that Microsoft is looking beyond one AI provider while keeping its Office AI pricing steady, at least under the reported plan. The underlying model mix may change, but the report does not describe a pricing change tied to the Anthropic addition.
The OpenAI relationship remains central
Microsoft maintains that its OpenAI relationship remains intact. A Microsoft spokesperson told Reuters that OpenAI will continue to be its partner on frontier models and that the company remains committed to the long-term partnership.
That relationship has been central to Microsoft’s AI strategy. Stretching back to 2019, Microsoft’s close partnership with OpenAI gave it an early advantage in AI assistants based on language models. It helped Microsoft move OpenAI-technology-based features into Bing search and roll out Copilot assistants across its software ecosystem.
The partnership has also involved major investment. Microsoft has poured over $13 billion into OpenAI to date and is currently negotiating terms for continued access to OpenAI’s models amid ongoing negotiations about their partnership terms.
Still, the record has not been simple. The rollout of OpenAI-technology-based features has been described as rapid, though bumpy. A recent report from the UK government found no clear productivity boost from using Copilot AI in daily work tasks among study participants.
AI companies are spreading their bets
The Anthropic move fits a wider pattern in which leading AI companies are reducing dependence on single partners or single infrastructure providers.
OpenAI has also begun to distance itself from its primary investor. In June, it struck a deal to use Google’s cloud computing infrastructure for AI, despite the two companies’ competition in the space. That marked a shift in OpenAI’s strategy to diversify its computing resources beyond Microsoft Azure, which had been its exclusive cloud provider until January.
OpenAI is also planning to launch a jobs platform that may compete with Microsoft’s LinkedIn. It also plans to begin mass-producing its own AI chips with Broadcom in 2026 to lessen its dependence on outside providers.
Microsoft has been diversifying as well. Beyond adding Anthropic to Office, the company has been developing its own proprietary AI models and began offering DeepSeek’s technology through its Azure cloud platform in January. Microsoft already offers multiple AI models, including Claude, through its GitHub Copilot development platform.
- Office 365 is reportedly adding Anthropic models alongside OpenAI technology.
- Claude Sonnet 4 reportedly performed better in some visual design and spreadsheet automation tasks.
- Microsoft will reportedly access Anthropic models through Amazon Web Services.
- Office AI subscription pricing is expected to remain unchanged.
- Microsoft says its OpenAI partnership remains intact.
What the shift means for Anthropic
For Anthropic, the Microsoft deal represents a significant paper win against its rival. The company was founded in 2021 by ex-OpenAI executives, including CEO Dario Amodei.
Anthropic has positioned its Claude models as “more steerable” alternatives to ChatGPT. Its relationship with Amazon is also important in this context. Amazon’s $4 billion investment, which began in 2023, gave Anthropic both capital and computing infrastructure through Amazon Web Services.
If the reported Office integration proceeds, Microsoft will indirectly use those Amazon Web Services resources to power its own products. That creates a tangled but revealing picture of the AI market: rivals in cloud, productivity software, and model development are also becoming suppliers, customers, and infrastructure partners.
The broader lesson is that AI platforms are moving toward flexibility. Microsoft’s Office 365 AI features may continue to use OpenAI technology, but the reported Anthropic addition shows that the company is willing to assign different model providers to different jobs when internal testing supports the switch.