Odense, Denmark, November 27, 2025, open-source web platform provider, Umbraco, has announced the general availability of Umbraco 17, the long-term supported (LTS) release of its core CMS platform built on the Microsoft .NET 10 framework.

Umbraco’s CMS platform underpins the websites and digital services of enterprises including Carlsberg Group, Thames Water, Baker Tilly, and Rubbermaid, and public sector organisations, including The Council of the European Union.

The latest iteration of the CMS platform continues to provide developers with the freedom to work with their preferred technologies and frameworks to extend and customise sites.

Importantly, Umbraco 17 introduces comprehensive load balancing, and enhanced search functionality, which allows customers to use their preferred search provider with the CMS platform.

Commenting on the new LTS, Umbraco CTO, Filip Bech Larsen said, “One of the features that I’m most excited about is load balancing. Starting with Umbraco 17, users can now load balance their Umbraco projects, including the back office. This will be a game-changer for enterprises that need to have several content editors working on their website at the same time.”

Explaining the benefits of the enhanced search capabilities, Filip Bech Larsen said, “Where our digital agency partners are being asked to include semantic search in customers’ sites, Umbraco 17 will enable them to plug in abstractions that deliver those capabilities.”

“Organisations that have built projects on Umbraco 13, our previous LTS version, will have a direct upgrade path to Umbraco 17,” adds Bolette Kern, senior product manager on Umbraco’s CMS team.

Features retained from Umbraco 13 LTS include:

  • Headless functionality in the core CMS.
  • Webhooks to enhance integration and allow website functionality to be extended.

“Organisations upgrading to Umbraco 17 LTS will also benefit from the new backoffice architecture, extensibility, security, headless capabilities, scalability, and performance enhancements brought into the core CMS over the past two years,” says Bolette Kern.

She points out that .NET 10 is also an LTS version of Microsoft’s software, observing that, “Being on the latest .NET version ensures that any optimisations and improvements incorporated into .NET 10 are also reflected in Umbraco 17. Both are LTS versions, which means that your Umbraco 17 projects will be future-proofed for at least three years.”

Umbraco is designed for customisation of projects built on the CMS platform and Filip Bech Larsen emphasises that this guides the product release strategy, saying, “We are committed to our CMS platform strategy of providing an extendable, future-proof foundation that grows and scales with your organisation. Umbraco takes a unique extension-first approach, where customisation is a first-class citizen. Umbraco 17 strengthens this aspect with even more extension points that are registered, documented, and supported, to ensure that organisations’ customisations are robust.”

The Umbraco 17 LTS also benefits from HybridCache for optimised content loading, and multi-site support features that were introduced in Umbraco 15, including:

  • Block Level Variations that allow international organisations to make local language content changes, while maintaining global brand consistency.
  • Role-based permissions controlled using the Client Credentials feature.
  • The replacement of Tiny MCE with a new text editor based on open-source rich text editor, TipTap, improves content editing and ensures license compliance out-of-the-box.

Additional information for organisations planning to migrate to Umbraco 17 can be found in Bolette Kern’s blog post here: https://umbraco.com/blog/umbraco -17-beta-is-out/

About Umbraco

Founded in 2003, Umbraco is the most widely-used open-source content management system built on Microsoft .NET. Umbraco’s user-friendly CMS seamlessly integrates with third-party applications to provide unparalleled flexibility and extensibility, empowering organizations to create bespoke websites and digital solutions tailored to their exact needs. Its intuitive interface simplifies web content management for editors. The combination of open-source, usability, extensibility, and scalability provides organizations of all sizes with a cost-effective, future-proof platform that grows with their business and offers impressive time-to-market for new digital solutions. Umbraco Cloud offers enterprise-level scalability, with regional hosting.

Umbraco’s success lies in the open-source model, a highly-engaged community of more than 250,000 developers and users, and a well-established global partner network of digital agencies.

Headquartered in Odense, Denmark, Umbraco employs 150+ people.