Microsoft is bringing xAI's Grok models into Copilot for Word, Excel, and PowerPoint, expanding an AI lineup inside its Office apps that already includes OpenAI and Anthropic. The move adds a third outside AI provider to Copilot and continues Microsoft's shift toward letting customers choose from several models instead of relying on just one.
How the Grok Rollout Works
The integration arrived through a Microsoft Tech Community blog post and was reinforced by CEO Satya Nadella, who wrote on social media, "More model choice coming to Copilot. Welcome Grok!" Access runs through the Microsoft Frontier Program, the company's track for previewing advanced features with a select group of enterprise customers, and it's available on both the web and desktop versions of Word, Excel, and PowerPoint.
Opt-In Controls and Data Handling
Grok isn't switched on automatically. Organization administrators have to opt in before any corporate data reaches xAI's models, and Microsoft has added xAI to its Online Services Subprocessor List to reflect the change. Frontier customers based in the European Union, the European Free Trade Association, and the United Kingdom are left out of this first preview.
Part of a Wider Multi-Model Strategy
Grok is the latest addition to a Copilot lineup that's been growing for months. Anthropic's models joined Copilot in Word back in August, and Grok 4.1 Fast has already been available to U.S.-based developers in Copilot Studio since a February preview. xAI has also released free Grok add-ins for PowerPoint, Word, and Excel through the Microsoft Marketplace earlier this year, plus a paid Outlook add-in and connectors for Teams, SharePoint, and OneDrive.
Microsoft says it will use customer feedback, usage data, and overall product fit gathered during the Frontier preview to decide whether Grok expands to more Copilot surfaces and wider commercial tiers. Every model added to Copilot, the company notes, goes through security validation and Responsible AI review before release.
What's Next for Grok and Copilot
The Office integration lands as xAI works on its next model. Elon Musk recently said Grok 4.7, reportedly scaling up to 2.1 trillion parameters, needs "a few more days to cook," pushing back a launch that had been expected this week. On Microsoft's side, Nadella confirmed during the company's July earnings call that the various Copilot experiences are being merged into a single, unified "super app."