Umbraco 17 migration guide: The .NET 10 foundation for your 2026 AI strategy

What is Umbraco 17?

Umbraco 17 is the Long Term Support (LTS) release of the Umbraco Content Management System, officially launched in December 2025. Unlike previous iterations of the Umbraco CMS system, Umbraco 17 is built entirely on Microsoft .NET 10 and features a completely modernised frontend architecture, removing legacy AngularJS dependencies. 

It is designed as a “model-agnostic” foundation, allowing organisations to integrate AI agents and external systems directly into the back office via the new Management API.

Setting the record straight: .NET 10 vs .NET 8

If you have been searching for information on the new release, you may have encountered conflicting reports suggesting that Umbraco 17 aligns with .NET 8.

Let us be clear: Umbraco 17 is built on .NET 10.

This distinction is critical for your 2026 technical roadmap. By skipping the interim step and aligning with Microsoft’s latest LTS framework (.NET 10), Umbraco ensures:

• Superior performance: Faster memory handling and execution speeds compared to .NET 8.
• Extended longevity: A support lifecycle that secures your digital platform well into the future.
• Security: Native access to the latest security protocols embedded in the .NET 10 ecosystem, ensuring data sovereignty and compliance for regulated sectors.

Comparison: Umbraco 13 (Old LTS) vs. Umbraco 17 (New LTS)

If you are currently running Umbraco 13, here is why 2026 is the year to migrate.

The real risks of technical debt if you delay migration

Staying on older versions like Umbraco 13 or earlier creates several forms of technical debt that increase over time:

1. Security vulnerabilities

• Legacy AngularJS backoffice components are no longer supported.
• Security patches are no longer issued, leaving your system exposed.

2. Rising maintenance costs

• Fewer developers now work with outdated frameworks.
• This makes specialist support harder to find and more expensive.

3. Slow, costly feature development

• New features must be built around old code, increasing development time.
• Testing becomes more complex due to outdated dependencies.

4. Barriers to AI adoption

• Old architecture limits your ability to integrate AI-powered workflows.
• Modern packages and automation features cannot be used efficiently.

5. Higher operational risk

• Ageing dependencies become fragile and prone to breaking.
• This increases the risk of outages, breaking changes and long recovery times.

6. Reduced scalability for 2026 and beyond

• A platform that can’t evolve quickly undermines your long-term digital strategy.
• Delayed migration makes future upgrades even more complicated and expensive.

The AI strategy: Don’t outsource, integrate

The most significant shift in Umbraco 17 is its handling of Artificial Intelligence. Rather than locking you into a specific AI vendor, Umbraco 17 adopts a model-agnostic approach.

Through the new Management API and the Umbraco Developer MCP (Model Context Protocol), we can now build systems where AI services read, write, and act within the back-office securely.

“Long-term digital success isn’t defined only by what comes in the box, but by how well a platform adapts when real-world needs evolve.” — Bolette Kern, Product Manager, Umbraco.

AI is powerful, but it is also energy-intensive. Umbraco 17 introduces the Sustainability Agent Profile (utilising agents.md). This open resource guides AI tools to act as focused, efficient assistants, ensuring that your use of Large Language Models (LLMs) remains cost-effective and environmentally conscious.

Your 2026 migration roadmap

Migrating to Umbraco 17 is a strategic move. At Imobisoft, our Umbraco experts break the process down into four distinct phases for our clients:

1. The audit: We review your existing packages (Forms, Commerce, Deploy) to ensure they are updated to their Umbraco 17-compliant versions.
2. The frontend refactor: This is the biggest technical shift. We migrate any legacy AngularJS property editors to the new UI Builder or standard Web Components. This removes years of technical debt in one go.
3. The cloud setup: We utilise the new CI/CD features in Umbraco Cloud, taking advantage of “Targeted Environment” deployments for safer testing, ensuring audit trails and zero-downtime deployments.
4. The AI layer: Once the platform is stable, we implement the Management API to connect your business workflows.

FAQ’s 

Is Umbraco 17 built on .NET 8 or .NET 10?

Umbraco 17 is built on .NET 10. While previous versions utilised .NET 8, the v17 release aligns with Microsoft’s latest framework for maximum performance and longevity.

Can I migrate directly from Umbraco 13 to Umbraco 17?

Yes. Umbraco provides a direct upgrade path from the previous LTS (version 13) to version 17. However, due to the removal of AngularJS, custom backoffice code will need to be refactored.

Is Umbraco 17 ready for AI integration?

Yes. Umbraco 17 is specifically designed as an “AI-Ready” foundation. It features a Management API that allows AI models to interact securely with your content and data without requiring complex third-party plugins.

How does the cost of Umbraco 17 compare for small businesses? 

While the Core CMS remains free and open-source, Umbraco 17 introduces a shift to subscription-based licensing for add-ons like Umbraco Forms (~$130/year) and Deploy. For small businesses, the most cost-effective comparison is often Umbraco Cloud (starting ~$55/month). This option bundles hosting, automated upgrades, and these licenses into a single predictable monthly fee, removing hidden maintenance costs compared to a standalone setup.

Lay the foundation for your 2026 AI strategy

Umbraco 17 isn’t just a version update; it is a new operating system for your digital content. By combining the power of .NET 10 with a flexible, AI-ready architecture, it sets the standard for 2026.

Are you ready to migrate?

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