Microsoft has started a limited Frontier-program test that adds xAI’s Grok models to Microsoft 365 Copilot in Word, Excel and PowerPoint. The move broadens Copilot beyond its long-standing association with OpenAI, positioning it as a platform that can offer users a choice of underlying AI models.
- Microsoft Word
- Microsoft Excel
- Microsoft PowerPoint
Microsoft has not said which Grok version is being used in the Office preview. That leaves an important open question, as xAI’s model lineup now includes systems with different capabilities and risk profiles.
Microsoft documentation already references Grok 4.1 Fast, but there is no confirmation that it is the model selected for this rollout. Microsoft’s own safety evaluations found Grok 4.1 Fast to be less aligned than other models it tested, with weaker safety and jailbreak-test results. The company also warns that it may be more likely than evaluated rivals to generate problematic content.
The addition follows Microsoft’s wider effort to support models beyond OpenAI’s, despite its multibillion-dollar investment in the ChatGPT maker. Anthropic’s Claude is already available within Microsoft 365 Copilot, reinforcing the company’s shift toward a multi-model Copilot strategy.
Grok’s Frontier preview is not currently available in the European Union, EFTA countries or the United Kingdom. Microsoft has yet to detail the specific Grok model involved or say when the feature could expand beyond the initial regions.
