Choosing Between Opus and GPT── Model choice inside Copilot, and how to choose outside it

Users can select different models using the model selector at the top right of the UI. By default, Copilot uses a real-time router to adjust the underlying model it uses based on your prompt.

On the AI providers operating as Microsoft subprocessors page, under Available subprocessors for your organization, select Anthropic, and Save.

This means that Anthropic (not Microsoft) stores most inputs and outputs for up to 30 days before deleting them.

Anthropic models deployed in Microsoft offerings such as Microsoft Copilot, Researcher, Copilot Studio, Power Platform, and Copilot in Microsoft 365 apps are currently excluded from the EU Data Boundary, and when applicable, in-country processing commitments.

Your admin must first allow access to Anthropic AI models in the Microsoft 365 admin center before you can use Claude in Researcher.

Copilot Cowork ships with several models so you can match the model to the work. Most of the time, leave the picker on Auto so Cowork can choose the model for your task.

Choose from more models. Claude Sonnet 5 and GPT-5.5 Chat are now generally available as primary models, giving you more options to match model capabilities to your agent scenario.

Audit logs for Microsoft Copilot and Microsoft Copilot Chat include the model provider and model name when a request is processed. This information can help support auditing, compliance, and governance requirements in organizations that enable multiple model providers.

If you're unsure which model to use, start with Claude Opus 5 for most workloads. Use Claude Fable 5.1 for demanding reasoning and long-horizon agentic work, or when your evals on Claude Opus 5 at higher effort still fall short.

OpenAI and Microsoft partnered together to optimize GPT-5.6 for knowledge work across Microsoft 365 apps and make it the preferred model for Microsoft 365 Copilot.

Access to SpaceXAI models is managed through a dedicated administrative setting that is disabled by default. Organizations that want to use these models enable the setting first, and administrators keep transparency and control over the data processed by SpaceXAI models in supported Copilot experiences. Access to Grok models is rolling out through the Microsoft Frontier Program in Microsoft Word, Excel, and PowerPoint.

Models are optimized for different purposes. Your agent can perform better when you choose a model with the strengths that fit your agent's purpose. For example, an agent that makes complex decisions can benefit from a deep model, while an agent expected to talk about a wide range of topics could use a general model.

Your agent starts with a default model optimized for most scenarios. To change your agent's model: Go to your agent's Overview page. In the Model section, select your agent's primary model. You can switch between experimental and production models at any time.

You can still use the retired model for up to one month after retirement.

Turn on external models in Power Platform admin center for the environment or the environment group.

Microsoft's safety and responsible AI evaluations found Grok-4.1 Fast (Non-Reasoning) to be less aligned than other models evaluated resulting in (i) higher risks that the model will produce potentially harmful content and (ii) lower scores on safety and jailbreak benchmarks.