What’s New in Umbraco 17?

Umbraco 17 is one of the most significant releases in the history of the Umbraco CMS, introducing a completely modern back office, support for .NET 10, enhancements powered by C# 14, improved editor experience, enterprise-ready load balancing, and long-term product support across the entire Umbraco ecosystem.

Umbraco 17 Overview: Why This Release Matters

Umbraco 17 delivers major improvements across performance, scalability, cloud-native readiness, and developer productivity.

Highlights include:

• New Web Components–based back office
• .NET 10 for unmatched speed
• C# 14 for cleaner coding
• Enhanced Backoffice load balancing
• Modern block-level variations
• Updated Umbraco Cloud, Forms, Engage, Deploy & Workflow

This version sets a new foundation for the future of Umbraco and is the ideal choice for businesses planning long-term digital experiences.

1. Umbraco 17 Runs on .NET 10: The Fastest and Most Secure .NET Runtime

Performance Improvements with .NET 10

Umbraco 17 benefits from major .NET 10 upgrades:

• Faster runtime, GC, JIT, and networking
• Better async performance
• Reduced memory usage

Native AOT Support for Umbraco

Native AOT delivers:

• Ultra-fast startup
• Smaller application footprint
• Better cloud hosting performance

This makes Umbraco 17 the best version for microservices, headless CMS, and containerized deployments.

Cloud-Native Enhancements

.NET 10 introduces deeper support for:

• Kubernetes deployments
• Open Telemetry
• Distributed tracing
• Built-in diagnostics

Perfect for enterprises scaling Umbraco Cloud or self-hosted cloud environments.

AI-Optimized Development

With .NET 10’s AI-friendly improvements:

• Better ONNX Runtime integration
• Faster AI/ML library execution
• Improved AI workflows

This enables businesses to build AI-powered digital experiences on Umbraco 17.

2. C# 14 Features That Improve Umbraco Development

Key Highlights:

• Primary constructors reduce boilerplate in Umbraco code
• Enhanced lambda expressions make inline logic cleaner
• Collection expression shortcuts like [...] simplify array/list creation
• Next-gen pattern matching improves data processing logic

These language improvements accelerate development for teams adopting Umbraco 17.

3. The New Umbraco 17 Backoffice: Faster, Extensible & Built for the Future

Modern Architecture Shift:

Benefits:

• Faster load times: Umbraco 17’s modern front-end architecture and optimized back office significantly reduce rendering and response times. Editors experience quicker navigation, faster content loading, and a smoother overall workflow, improving both productivity and user satisfaction.
• Easier customizations: With the new Extension API and Web Components–based backoffice, developers can build and integrate custom features more efficiently than ever. The modular design allows cleaner, more predictable customizations without complex workarounds or breaking core functionality.
• Better long-term maintainability: The updated technology stack removes outdated frameworks and ensures your implementation stays aligned with modern development standards. This results in cleaner code, fewer technical dependencies, and easier long-term maintenance as your project evolves.
• Stable architecture for future upgrades: Umbraco 17 introduces a future-proof foundation designed to support seamless updates in the coming versions. With standardized APIs and a more consistent structure, upgrades become less disruptive, reducing both risk and time spent on technical transitions.

UI & Accessibility Enhancements

• New custom entity icons: Umbraco 17 introduces new custom entity icons that clearly indicate states such as “Unpublished Changes” or “Restricted Node.” These visual cues improve clarity, helping editors quickly understand content status and navigate the back office with a more intuitive and user-friendly experience.
• Improved “Create” actions in lists, trees & collections: The updated “Create” actions allow editors to add new items directly from list views, trees, and collections without navigating through multiple screens. This streamlines content creation workflows, reduces clicks, and speeds up day-to-day publishing tasks.
• Deep links for editor navigation: Deep linking enables editors to bookmark and share precise locations in the back office. Whether it’s a specific content node, settings page, or dashboard, deep links make collaboration easier and allow teams to jump directly to the exact view they need.
• Strong accessibility improvements: Enhanced keyboard navigation, improved contrast, screen-reader-friendly markup, and compliance-focused updates make the Umbraco 17 back office more accessible for all users. These improvements support inclusive content management and align with modern accessibility standards.

This makes the Umbraco 17 back office more user-friendly and editor-focused.

4. Backend Improvements in Umbraco 17

Updated Models Builder

In Umbraco 17, runtime Razor compilation has been removed. Instead, a new library — Umbraco.Cms.DevelopmentMode.Backoffice — handles model generation. This modern approach speeds up model creation, simplifies development workflows, and provides a more efficient alternative to the old runtime compilation process.

New DateType Editor & Consistent UTC Handling

Umbraco 17 introduces a foundational improvement that significantly enhances reliability across global editorial teams: consistent UTC date handling. All system dates—such as creation, updates, publishing schedules, and logs—are now stored and interpreted in UTC. This ensures that every server and editor, regardless of location, works with the same exact timestamp.

This change eliminates common issues like regional time drift, inconsistent scheduling, and mismatched logs. For example, an editor in London can schedule content to publish at 09:00 UK time, while a colleague in New York sees the correct equivalent time in their own time zone. Because the underlying value is stored in UTC, the server publishes at the exact expected moment.

To support this shift, Umbraco 17 also introduces an improved Date Time Picker. It includes:

• Date, time, and time zone selection
• Customizable time zone lists to simplify options for editors
• Clearer visual design for more intuitive scheduling

This new editor is especially beneficial for global websites and distributed teams, as it reduces confusion and ensures accuracy when managing time-sensitive content.

5. Editor Experience Upgrades: Block-Based Editing in Umbraco 17

Key Updates

Nested Content → Block List (modern alternative)

• Umbraco 17 continues the evolution toward a fully block-based editing experience by replacing the older Nested Content with the more powerful Block List Editor. Block List offers richer configuration, better UX, structured data consistency, and improved design flexibility. Editors gain a cleaner, more visual way to manage repeatable content, while developers benefit from a more maintainable and future-proof architecture.

Grid Layout → Block Grid Editor

• The classic Grid Layout has now been upgraded to the Block Grid Editor, giving editors a modern, intuitive way to build page layouts using flexible blocks. With improved drag-and-drop controls, visual previews, and customizable block types, Block Grid brings layout building closer to actual content design—making complex layouts easier to create, maintain, and reuse.

Macros → RTE Block-based embeds

• Traditional Macros have been replaced with RTE block-based embeds, providing a cleaner, more structured way to insert interactive or dynamic elements inside rich text. This modern approach aligns RTE behavior with the rest of Umbraco’s block architecture, resulting in better consistency, stronger validation, and an improved editing experience free from legacy macro limitations.

This creates:

• Better content flexibility
• Better structured content
• Easier page-building for editors

6. Umbraco Backoffice Load Balancing

Enhancements Include

Updated repository caching: Cache Versioning

• Each server tracks a cache version number
• Changes increment the version identifier
• Servers automatically detect outdated caches
• Out-of-sync caches are invalidated and refreshed on demand

Reliable background tasks

Umbraco 17 introduces IDistributedBackgroundJob, which uses database coordination to ensure jobs run on only one server at a time, even in a multi-server environment.

Stability for long-running operations

Long-running operations, such as publishing large content structures or performing bulk updates, receive significant stability improvements in Umbraco 17. These operations are now better managed and monitored, reducing the risk of timeouts or failures. Teams working with large datasets or complex workflows benefit from a smoother and more dependable publishing experience.

Reduced dependency on local file systems

When the Backoffice is load-balanced, Umbraco relies on shared temporary files for uploads and processing.

SignalR improvements for real-time communication

The Umbraco Backoffice uses SignalR extensively for real-time updates, such as: Content editing notifications, User activity indicators, Publishing status updates, and Cache refresher events.

Ensure SignalR is configured correctly for distributed environments.

7. Upgrade Considerations: Before You Move to Umbraco 17

Important Changes

System dates now default to UTC:

• All system timestamps are now stored and interpreted in UTC, ensuring consistent scheduling and logs across regions. Validate any custom date logic that previously relied on local server time.

If Your Models Builder is set to InMemory-only, then

• As Runtime Razor compilation is removed, and InMemory model generation is now the default. Review your development workflow to ensure compatibility with this updated model-building approach.
• Projects upgrading from v13 must install the external Models Builder package Umbraco.Cms.DevelopmentMode.Backoffice as it’s no longer included by default. Missing this step prevents content models from being generated.
• If this package is not installed, Umbraco will fail during startup with boot errors.

Single Block Property automatically migrated

• Umbraco 17 has introduced the new Single Block Property Editor, and any blocks with a maximum set to 1 will be upgraded automatically. Test custom setups to ensure that rendering and validation behave as expected after the migration.

Version-specific upgrade notes required

• Upgrading across multiple major versions requires reviewing notes for versions 14 to 17. Skipping them may cause unresolved API changes, compile issues, or breaking behavior.

Backoffice customizations must be updated

• AngularJS-based customizations will no longer work in Umbraco 17. All custom backoffice components must be adapted to the new Web Components architecture.
• Custom property editors, dashboards, and UI elements must be rebuilt using the new Extension API. This ensures compatibility and stability with the re-engineered v17 back office.

8. Umbraco Product Updates for Version 17

Highlights

• Umbraco Developer MCP → Final version released
• Umbraco Cloud → Version 17 available on launch day
• Umbraco Engage → Fully aligned with Umbraco 17 LTS
• Umbraco Forms → Licensing & subscription updates
• Umbraco Workflow → New Release Sets (plan, group & publish content)
• Umbraco UI Builder → Now the perfect time to adopt
• Umbraco Deploy → Engage support now available

This ecosystem ensures businesses get a future-proof CMS platform.

Why Upgrade to Umbraco 17?

• Significant performance boost with .NET 10
• More stable, modern, maintainable back office
• Better developer experience with C# 14
• Improved editor workflows with block-based editing
• Enterprise-grade scalability and load balancing
• Long-term support and product ecosystem compatibility
• Perfect foundation for headless CMS, cloud-native hosting, and AI-powered experiences

Conclusion: Umbraco 17 Is the Most Future-Ready Version Yet

Umbraco 17 sets a new benchmark for speed, scalability, and modern content management. With its .NET 10 foundation, new backoffice, enhanced editor tools, and enterprise-ready features, it’s the ideal platform for businesses looking to future-proof their digital presence.

And, if you are considering upgrading or starting a new project on Umbraco 17, then Giriraj Digital has got you covered. We are a leading Umbraco Gold partner with a team of Certified Umbraco developers and experts who understand your needs and offer you personalized services.

For further discussion, book a free consultation call now!