Office Online Server – Microsoft announces end of support

Microsoft has officially announced that it will discontinue support and further development of Office Online Server on December 31, 2026. This decision is part of Microsoft’s strategy to focus more on cloud-first solutions and modern productivity platforms such as Microsoft 365.

What does the end of support mean?

The Office Online Server has previously enabled browser-based use of Office applications (Word, Excel, PowerPoint) in local environments. After December 31, 2026, continued use will result in significant potential risks:

• Security risks: Without security updates, systems are vulnerable to new threats.
• No technical support: Errors or stability issues can no longer be resolved.
• Compliance risks: Using unsupported software may violate regulatory requirements.

How does this affect you in practice?

For companies and users, the end of support will bring noticeable changes to their everyday work.
Specifically, this means:

• Documents can no longer be opened directly in the browser as usual.
• All documents available online must be manually converted or migrated in order to continue to be edited.
• Employees will have to install local Office applications in the future, as direct access via the browser will no longer be possible.
• Organizations with an on-premises SharePoint farm will no longer be able to work on documents simultaneously in SharePoint and edit them collaboratively from the end of 2026.

Although locally installed Office programs offer more features and functionality, the familiar browser-based working environment will be lost – a noticeable change, especially for teams that have previously worked entirely online. Since Microsoft will not be offering an equivalent successor solution for on-premises customers from 2026 onwards and will only be referring to cloud-based alternatives, this is often not a realistic option for security-critical environments.

What are the consequences for companies?

For organizations, the end of support for Office Online Server means more than just technical adjustments—it affects entire processes, projects, and licensing structures. In practice, this is particularly evident in the following areas:

• Time-consuming adjustments: Existing documents, processes, and integrations must be reviewed and adapted.
• Potential financial burdens: The additional effort may lead to project delays or additional costs.
• Special features in Citrix environments: Here, Office licenses must be reassigned and activated in accordance with security requirements—a process that takes additional time.

Experience shows that user adoption, the complete transition to and acceptance of the new way of working, takes at least six months, depending on the size, complexity, and applications used.

What are the alternatives?

Microsoft recommends switching to Microsoft 365, where future developments and investments will be bundled. The focus here is on Office for the web as a modern, secure, and collaborative solution with advantages such as:

• Real-time collaboration and automatic updates
• Seamless integration with Teams, SharePoint, and OneDrive
• Advanced security and compliance features
• Access to Microsoft 365 Copilot for AI-powered productivity

However, for companies that want to continue working on-premises, there are alternatives to Office Online Server, such as OnlyOffice Docs or Collabora Online. When making your selection, you should pay particular attention to the following aspects:

• Compatibility with your SharePoint version – The SharePoint version you are using must be supported – an upgrade may be necessary.
• Browser-based document editing – Word, Excel, and PowerPoint files should be usable directly in the browser.
• Integration with SharePoint libraries – Seamless integration with SharePoint libraries ensures a consistent user experience.
• Data sovereignty and hosting options – Whether cloud or on-premises, the solution must fit your infrastructure.
• Migration effort and feature comparison – The change should be made with as little effort as possible and without additional processes.
• Performance and scalability – Important Office Online Server features as well as stability and scalability must be guaranteed.

If you are looking for a long-term solution that works optimally with your on-premises SharePoint, it is worth taking a strategic look at possible alternatives.

Act now: Plan your migration in good time and implement it efficiently

Support will end irrevocably on December 31, 2026. Timely planning is the key to a smooth transition. It is important to take stock of the situation:

• Which systems and applications currently use Office Online Server?
• What measures need to be taken with regard to compatibility?
• What dependencies exist with SharePoint, Power BI, or other services?
• Which Microsoft 365 or hybrid solution best fits your long-term IT strategy?

It is also important to consider user acceptance at an early stage: the transition will only be successful if employees are well trained and supported.

Setting the course for future-oriented IT

SPIRIT/21 supports you in analyzing your existing systems, develops a suitable migration strategy, and accompanies you from planning to successful implementation -
so that your IT environment remains secure, stable, and future-proof even after 2026. Taking action now will not only cushion the financial impact, but also provide an opportunity to modernize your IT landscape for the long term.

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