Microsoft retires Office Online Server
Microsoft is shutting down Office Online Server, the on-premises version of Word, Excel, PowerPoint, and OneNote that organizations could host in their own data centers. It was mostly used by governments and industries with strict security rules, places where cloud storage wasn’t allowed. That era now has an expiration date: support ends on December 31, 2026, and after that, there will be no updates, no security patches, and no support.
Officially, Microsoft says it wants to focus on “modern productivity tools” and streamline investments into cloud-first products like Microsoft 365. In reality, Office Online Server has been fading for years as fewer companies used it, and Microsoft clearly wants everyone inside its cloud ecosystem where subscriptions and AI features live.
Once support ends, organizations that stick with Office Online Server will be running unsecured software, making them easy targets for cyberattacks. The practical outcome is simple: most users will be forced to migrate to Microsoft 365. AI is also part of the story here. Microsoft is investing heavily in Copilot and other AI integrations, but none of these advancements are being applied to legacy on-premises products. To access the latest tools, you must move to the cloud.
Still, not everything is disappearing. SharePoint Server Subscription Edition and Exchange Server will continue to be supported for now. Companies using those can still view and edit documents using Microsoft 365 Apps for Enterprise or Office LTSC 2024. However, there are casualties. For example, Power BI Report Server will no longer support Excel workbooks hosted via Office Online Server. The only alternatives are using desktop Excel or moving to Power BI in the cloud.
For many companies, migration won’t be quick. Those using Office Online Server often did so precisely to keep control over data. Moving to the cloud means rethinking security policies, internal workflows, and compliance requirements. Microsoft advises starting planning now, because after 2026, staying on Office Online Server becomes too risky.
To make the move, companies will have to pick from Microsoft 365 plans:
Business Basic – $6/user/month (web apps only)
Business Standard – $12.50/user/month (adds desktop apps)
Business Premium – $22/user/month (adds security and device management)
The message from Microsoft is clear: the future of Office is subscription-based, cloud-connected, and AI-driven, and there’s no path backward.
