Microsoft to Retire Office Online Server in December 2026

Microsoft has retired several legacy services this year alone, including the Microsoft Lens app and older components of Skype for Business. Now, the company has confirmed that Office Online Server is also heading for the same fate.

In an announcement published today, Microsoft said it will end support and retire Office Online Server on December 31, 2026. After this date, Office Online Server will no longer receive security updates, bug fixes, or technical support, effectively leaving it unsafe and non-compliant for enterprise use.

Microsoft says the decision will help it achieve its goal to “modernize productivity experiences” and focus fully on cloud-first solutions like Microsoft 365. The company clarified that this announcement doesn’t affect other server products such as Exchange Server Subscription Edition, SharePoint Server Subscription Edition, or Skype for Business Server Subscription Edition.

The company recommends that organizations relying on Office Online Server should begin planning their migration to Microsoft 365 to ensure security and compliance. For businesses that depend on Office Online Server for collaborative document editing or browser-based Office access, Microsoft 365 offers a more advanced replacement.

Organizations using Power BI Report Server with Excel integrations will also need to prepare for change. That’s because hosting Excel workbooks through Office Online Server will no longer be supported after the retirement date. Microsoft suggests using the Excel desktop app or migrating workloads to the Power BI service instead.

Moreover, the company is encouraging customers to start transition planning early, with migration help available through Microsoft FastTrack for organizations with more than 150 licenses.