xAI launches Grok for Excel, a free Microsoft 365 add-in

xAI has shipped Grok for Excel, a free Microsoft 365 add-in that puts its Grok assistant directly inside spreadsheets. "Today we're bringing Grok into Microsoft Excel," the company said in its announcement, positioning the release as the latest piece of a wider push into Microsoft's Office suite.

What's new

Grok for Excel installs from the Microsoft Marketplace and docks as a panel beside an open workbook rather than opening a separate tab. Users can select a range of cells and ask what changed and why, and the add-in answers with citations back to the specific cells it used, dropping charts directly into the sheet next to the data. It can also write formulas from a plain-English description of the desired outcome, landing real, editable formulas in the formula bar rather than static output, and it can rerun scenarios, such as a downside case or a fresh forecast, while flagging which cells changed.

The add-in can pull in outside context through Grok's connectors, letting it reference recent emails or files stored in SharePoint or Google Drive when building a model. xAI says data stays inside the workbook rather than leaving the user's environment. Excel joins Word, PowerPoint, and Outlook, which already have their own Grok add-ins; xAI shipped the PowerPoint version about a month earlier, on June 16.

Context

The add-ins run on Grok 4.5, which xAI launched July 8. Rolling the same assistant out across the core Office apps mirrors the strategy Microsoft itself has used to embed Copilot everywhere a user works, and it puts xAI in direct competition with both Microsoft's own in-house models and OpenAI's tools, which have long powered various AI features across Office. Getting Grok installed as a first-class Microsoft 365 add-in, distributed through Microsoft's own Marketplace, also gives xAI a distribution channel into enterprise spreadsheets and documents that it doesn't otherwise have through the standalone Grok app or the X platform.

Why it matters

Spreadsheet and document work is one of the most concrete, high-frequency use cases for an AI assistant in a business setting, and it's a market Microsoft has spent years trying to own with Copilot. By shipping free, direct-install add-ins for Excel, Word, PowerPoint, and Outlook rather than trying to pull users into a separate Grok interface, xAI is betting that meeting people inside the tools they already use daily is a faster path to enterprise adoption than building a standalone destination. It's also a sign of how quickly the frontier labs are converging on the same office-productivity battleground, following similar moves by OpenAI and Google to wire their models into everyday work software.