You've got an idea for an Excel spreadsheet, but building it is another matter. Microsoft's Copilot can help, and now SpaceXAI is offering an alternative: the Grok add-in for Excel.

Available on the Microsoft Marketplace, the add-in places a sidebar in Excel that can "search the web, update spreadsheets, or build powerful financial models," according to the product description

It isn't without cost. The add-in is currently available for SuperGrok, Heavy, Business, and Enterprise plans, although, as xAI states, the Microsoft 365 add-in itself is free.

xAI is parking its tanks on Microsoft's Copilot lawn with the add-in, although the level of integration is quite a bit lower. For example, in 2025, Microsoft announced a COPILOT function in Excel allowing users to invoke its assistant at the workbook cell level. At its most basic, Grok turns prompts into workbook actions. However, we'd strongly recommend that a human review the results, just in case the AI has spewed nonsense.

Grok, the AI that spawned MechaHitler and non-consensual deepfake nudes, hit version 4.5 this month and xAI claimed it was "capable of building complex Excel models." Grok Build was then caught sending entire repositories to the cloud, before boss Elon Musk stated that Grok Build CLI would be open source.

All of which should give users pause before installing the component. Microsoft warns: "When this app is used, it can read and make changes to your document, can send data over the internet."

The add-in inserts a button on Excel's ribbon to show the Grok pane. Text can then be entered. We asked it to "create a chart showing SpaceX stock performance since IPO, with the y axis showing value and the x axis showing time."

Grok said it had reached usage limits and suggested that we upgrade our plan. Thinking that might have been a bit complicated, we tried simpler requests, all of which failed, confirming that a subscription is indeed required.

This puts Grok up against some tough competition. Copilot is deeply entrenched in Microsoft's Office applications, and Google is not shy about promoting Gemini in its productivity tools. Organizations that already have a Grok subscription might get some value from the add-in, but others are spoiled for choice when it comes to AI assistants in their productivity applications.

An Excel esports championship for AI assistants, anyone? ®