Grok is now a selectable model family inside Microsoft 365 Copilot for Word, Excel and PowerPoint, but only for eligible Microsoft Frontier Program customers and only after a tenant administrator turns it on. Microsoft announced the change on its Copilot blog on 12 September 2026, framing it as the next step in a multi-model strategy rather than a change of default: the dedicated SpaceXAI setting ships disabled, and access is being released in a focused preview so the company can see how customers use it for everyday productivity work.
Key facts
| Fact | Detail |
|---|---|
| Question answered | Microsoft 365 Copilot Adds Grok for Word, Excel and PowerPoint |
| Short answer | Microsoft has added Grok models from SpaceXAI to Copilot in Word, Excel and PowerPoint through the Microsoft Frontier Program. |
| Reading time | ~4 min |
| Last updated | 2026-09-14 |
What Microsoft actually announced
The official post confirms four things that matter more than the headline. First, Grok models from SpaceXAI are being added to Copilot, which turns the assistant into a genuinely multi-vendor surface rather than an OpenAI-only one. Second, SpaceXAI has been added to Microsoft’s Online Services Subprocessor List, which is what makes the administrative toggle possible in the first place. Third, the rollout is limited to Word, Excel and PowerPoint for now, and Microsoft says it will evaluate feedback, usage patterns and product fit before widening availability to other Copilot experiences and surfaces. Fourth, before any model reaches customers it goes through testing, safety validation and Responsible AI reviews.
There is a regional carve-out during the preview. Microsoft states that Grok is not available to Frontier customers in the European Union, the European Free Trade Association countries, or the United Kingdom.
Chinese tech outlet ITHome, which reported the same announcement, adds two useful details. Microsoft did not disclose which specific Grok model is being served - xAI’s current flagship is Grok 4.6 - and the vendor has previously brought Anthropic’s Claude into Researcher and Copilot Studio, which is why the model picker is no longer a single-vendor menu.
Why the administrator gate is the real story
For anyone deploying software inside a company, the interesting part is not the model name. It is that a third-party model can now be reached from a document, and that the data path is treated as a subprocessor relationship. Administrators get both the switch and the visibility: they can see and control the Copilot features where data is processed by SpaceXAI models, and nothing happens until they opt in. That is a reasonable default, but it also means two people on the same Microsoft 365 tenant can have completely different experiences in the same Word document.
What this means if you run an AI agent on your own PC
Model choice inside a rented productivity suite is someone else’s decision: it depends on your tenant’s region, your administrator’s toggle, and which preview programme you are enrolled in. On your own Windows machine the trade-off is different, because the choice belongs to you - along with the question of what the agent is allowed to touch.
That is the design MOOGH is built around. Instead of reaching into your documents from a cloud tenant, MOOGH runs as a desktop client on Windows 10 and 11: you describe a task, it plans the steps, asks for your approval, and then executes locally - file operations, command execution, coding fixes and routine automation. Nothing is decided by a tenant administrator, and there is no separate preview queue for a model toggle. If you want that kind of local, approval-first control over what an agent does on your PC, you can download MOOGH from the official page and try it on your own machine.
The broader direction is clear either way. Microsoft is normalising the idea that one assistant should be able to call several vendors’ models, and enterprises are being asked to manage that as a data-processing question rather than a feature flag. Desktop agents will be held to the same standard, which is why local approval steps and a visible record of what ran where are worth more than a longer model list.
FAQ
Is Grok available to everyone in Word, Excel and PowerPoint? No - it is a Frontier Program preview, and it is disabled at tenant level until an administrator enables the SpaceXAI setting.
Which model version is it? Microsoft has not said. The announcement describes Grok as the SpaceXAI model family, and ITHome notes the current xAI flagship is Grok 4.6.
Where is it blocked? The EU, EFTA countries and the UK are excluded during the preview.
Sources: the Microsoft Copilot Blog post Expanding model choice in Copilot with Grok (12 September 2026) and ITHome (14 September 2026).
Download: MOOGH
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