Microsoft shifts some Copilot work to its own MAI models
Microsoft has started handling part of the Copilot workload in Excel and Outlook with its own instead of OpenAI and Anthropic models. The models are already taking tens of thousands of prompts each week across the two apps.
Excel and Outlook were previously described as relying heavily on OpenAI and Anthropic models. This change shows Microsoft using its own models as a live re inside real products, not just as a research project or side option.
Microsoft’s stock rose 1.75% that day, suggesting investors saw the news mainly as a cost and margin story. Because Copilot inside Office is one of Microsoft’s highest-use AI surfaces, even a partial switch could change how much Microsoft pays outside AI companies to bundle AI into everyday work tools.
Key points
- Microsoft has moved some Excel and Outlook Copilot work to its own .
- The shift covers tens of thousands of prompts each week across the two apps.
- The work previously relied heavily on OpenAI and Anthropic models.
- This is a live product re, not just an internal research test.
- Microsoft’s stock rose 1.75% on the day, pointing to investor focus on lower AI costs.