GPT-5.6 becomes default model powering Microsoft 365 Copilot

Microsoft 365 Copilot users are now getting responses powered by OpenAI’s GPT-5.6 model, marking a significant upgrade to the AI assistant that millions use daily across Office applications. OpenAI announced the integration today, positioning GPT-5.6 as the preferred model for delivering faster and higher-quality AI assistance.

The change affects Copilot functionality across Word, Excel, PowerPoint, Chat, and the newer Cowork collaboration features. Users won’t need to take any action to access the upgraded model — it’s rolling out automatically as the new default.

Enhanced Performance Across Office Apps

GPT-5.6 brings measurable improvements to common Copilot tasks like document drafting, data analysis, and presentation creation. The model processes requests faster while generating more contextually relevant suggestions, particularly for complex multi-step workflows that span multiple applications.

In Excel, this translates to better formula suggestions and more accurate data interpretation. Word users will see improved writing assistance that better maintains document tone and style consistency. PowerPoint gets smarter slide generation that aligns more closely with existing presentation themes and content flow.

Stronger Integration with Cowork Features

Microsoft’s Cowork functionality, which enables real-time AI collaboration across teams, receives particular attention in this update. GPT-5.6’s improved reasoning capabilities help the AI better understand project context when multiple team members are working simultaneously on shared documents.

The model can now track conversation threads more effectively and provide suggestions that account for different team members’ roles and contributions. This addresses previous limitations where Copilot sometimes offered generic advice that didn’t fit specific collaborative workflows.

Chat and Communication Improvements

The Chat component of Microsoft 365 Copilot now leverages GPT-5.6’s enhanced natural language understanding to provide more nuanced responses to workplace queries. The model better interprets requests that reference multiple data sources or require cross-application knowledge.

Users asking questions that involve both calendar data and email context, for example, should see more comprehensive and actionable responses. The upgrade also improves Copilot’s ability to maintain conversation context across longer chat sessions.

Bottom Line

This represents the largest AI capability jump for Microsoft 365 Copilot since its initial launch. GPT-5.6’s integration should make the assistant noticeably more useful for complex knowledge work, particularly for teams already using Cowork features. The automatic rollout means existing Copilot subscribers get immediate access to improved performance without additional costs or setup requirements. Watch for Microsoft to highlight specific productivity metrics as the deployment completes across their user base.