Microsoft 365 Copilot: Retirement of the Sites control in Researcher

The Sites control in Microsoft 365 Copilot Researcher for Frontier users will be retired by late September 2026. Users can still specify preferred websites directly in prompts. No admin action or new settings are needed; existing web search controls remain unchanged. Inform users and update documentation accordingly.

[What and why]

We are retiring the Sites control in Microsoft 365 Copilot Researcher for users enabled for Frontier. Today, the Sites control allows users to enter and maintain a list of websites when creating a research request.

After this change, users can continue to guide Researcher to preferred websites by referencing website names or URLs directly in their prompts. For example: "Research this topic using information from contoso.com and fabrikam.com."

This update simplifies the Researcher experience while modernizing the underlying platform. Existing tenant-level web search controls will continue to determine whether Researcher can use web content. Specifying website names or URLs in a prompt indicates a user's preferred research scope and does not function as an administrator-managed allowlist or blocklist.

[Rollout schedule]

• Retirement for Frontier (Worldwide): Beginning in late September 2026 and expected to complete in late September 2026

[Impact on your organization]

Who is affected

• Users with a Microsoft 365 Copilot license who are enabled for Frontier and currently use Researcher

Platforms and services

• Microsoft 365 Copilot
• Researcher
• Frontier

What will happen

• The dedicated Sites control will be removed from the Researcher prompt experience.
• Users will no longer be able to add or manage websites through the Sites control.
• Users can continue to specify preferred websites by including website names or URLs directly in their prompts.
• Existing tenant-level web search settings will continue to govern whether Researcher can access web content.
• No changes are being made to administrator-configured website controls for Researcher with Computer Use.
• No new admin settings are being introduced.
• Existing web search governance and controls remain unchanged.

[Action required and recommendations]

No administrator action is required.

We recommend that you:

• Inform impacted users that the Sites control is being retired.
• Update any internal training or documentation that references the Sites control.
• Remind users that website preferences can continue to be specified directly within Researcher prompts.
• Review existing web search settings if you want to confirm how web content is governed in your organization.

[Compliance considerations]

No compliance considerations identified, review as appropriate for your organization.