Following·Day 208·first covered 19 Feb 2026·8 sources

Microsoft Copilot Adds Grok and Claude as Selectable Model Options

The gist

Enterprise users of Microsoft 365 Copilot can now choose among models from multiple AI providers within a single platform, though each requires admin action to activate. Data routing to third-party providers introduces privacy considerations that organizations must weigh when enabling these options.

The full picture

Microsoft Copilot now offers xAI's Grok and Anthropic's Claude as selectable alternatives to its default OpenAI models across several products. The Grok rollout into Word, Excel, and PowerPoint began September 12, 2026, as a limited preview for Microsoft Frontier Program customers. Grok 4.6 became available in GitHub Copilot on August 14, 2026, and Grok 4.1 Fast has been available in Copilot Studio since February 2026. Claude is available via a model picker in Microsoft 365 Copilot for specific features, with the Researcher agent described as the clearest place to make that switch. Both third-party options are off by default and require IT administrator enablement. Grok is not available to Frontier customers in the EU, EFTA, or UK during the preview period, and Claude is off by default in the EU and UK. Microsoft notes that using Grok routes data to xAI servers, and xAI has been added to Microsoft's online services sub-processor list.

How it developed

14 September 2026

Reports that Microsoft 365 Copilot's model picker, allowing Claude as an alternative to the default OpenAI model, has been available since earlier in 2026

12 September 2026

Grok models from xAI announced as rolling out in Copilot for Word, Excel, and PowerPoint, starting with Microsoft Frontier program customers

19 February 2026

Grok 4.1 Fast added to Copilot Studio as a preview model, off by default and requiring admin opt-in

Sources

Grok / xAI Twitter