SharePoint Online to Use a New Public Content Delivery Service by July 2025: Action Required

SharePoint Online will transition from the current Office 365 content delivery network (CDN) to using Azure Front Door starting June 2025, and the transition is planned for completion by July 2025. The Office 365 CDN is used to host static assets delivered by SharePoint Online pages, such as graphics and documents, closer to the requesting user for improved performance.

This change to Azure Front Door will happen automatically. However, organizations that use network allow lists must ensure the new URL, “public-cdn.sharepointonline.com,” is included. The previous Office 365 CDN URL, “publiccdn.sharepointonline.com,” is still active and should not be blocked until Microsoft provides further guidance. In addition, administrators and developers should be notified about this change if they explicitly refer to the Office 365 CDN URL in any scripts or custom applications and should avoid hardcoding CDN URLs in the future.

SharePoint Online’s use of a new public CDN is documented in the Microsoft 365 Message Center message “MC1066155” (requires access to the Microsoft 365 admin center).