Microsoft Routes Excel, Word AI Prompts to In-House Models as Costs Rise

Q: Is Microsoft's new AI model the first step in its strategic pivot away from partner OpenAI?

Yes. Microsoft’s rollout of its in-house MAI models in Excel and Outlook is a clear early sign of a strategic shift toward reducing dependence on OpenAI, even if it does not yet amount to a full break. The strongest evidence is operational. Microsoft has begun routing tens of thousands of weekly AI prompts in core products to MAI models instead of relying as heavily on OpenAI and Anthropic. That is not a small experiment at the margins; it places Microsoft’s own models inside widely used commercial software where cost, reliability and control matter most. The stated motive also points to a broader pivot. Microsoft is using MAI to cut AI operating costs, suggesting it wants more control over the economics of serving AI features at scale. Building and deploying its own models gives it leverage over pricing, product integration and technical roadmaps in ways that dependence on outside partners does not. That said, the move should be seen as a partial diversification rather than definitive separation. The available information shows Microsoft is replacing some workloads, not all of them, and OpenAI remains an important partner in the broader AI ecosystem. What has changed is that Microsoft is no longer treating external models as the default for every major product use case. So this looks like the first concrete step in a strategic rebalancing: less reliance on OpenAI for routine product tasks, more use of Microsoft’s own AI where it can lower costs and tighten control.

3 articles · Updated · TechCrunch · Jul 7

Microsoft has started answering a share of Excel and Word user prompts with its own MAI models, reducing how much those Office features depend on OpenAI and Anthropic systems.
Rising AI costs are driving the shift, with Microsoft joining a broader push by tech companies to trim spending after an earlier burst of heavy model usage.
Seven new MAI models unveiled at Microsoft's Build conference last month show the company is still expanding its internal AI stack, including an agentic coder and a text-to-image generator.
Amazon, Uber, Meta and Accenture have also moved to curb AI spending, while some Silicon Valley companies are weighing cheaper Chinese models despite security concerns.