Umbraco 13 vs. Umbraco 17: Should You Upgrade Now?

What is Umbraco 13?    

Umbraco 13 is a long-term support (LTS) version of a popular open-source content management system (CMS), released in December 2023. It’s a reliable, tried-and-true tool built on .NET 8 and C# 12. On December 14, 2026, Umbraco 13 reaches its end of life. That means no official support, security patches, or bug fixes from Umbraco HQ by the end of this year, making the Umbraco 13 upgrade inevitable.

What is Umbraco 17?

Umbraco 17 is the latest LTS version of the Umbraco CMS, released in November 2025. This is the current supported platform baseline for long-term planning, as it will ensure a stable support until late 2028. Umbraco 17 runs on .NET 10 LTS, including a mature version of the new backoffice architecture.

Key changes in Umbraco 17

Here is the list of Umbraco 17 new features and how they affect your operations:

• Modern backoffice architecture. Introduced in version 14, it was stabilized in v17. The new architecture makes building custom UIs easier, enables deeper customization of the admin interface, and provides editors with a faster, more stable multi-user workflow.

• Latest .NET LTS release as the cornerstone. Umbraco 17 is based on .NET 10 LTS, which will receive security patches and updates until late 2028. That means a single, predictable upgrade will help your team stay compliant and secure across the technical stack for years.

• Improved horizontal scaling. The administrative interface can run across multiple servers simultaneously, which removes the previous single-server limitation for editorial teams.

• UTC-based date handling with migration. Umbraco 17 automates migrating local server times to UTC, ensuring data consistency for global teams and scheduled publishing.

• Updated extension model and removed obsolete code. With the new manifest-driven extension model and less legacy code, Umbraco 17 offers better performance and security. At the same time, if you aim to upgrade Umbraco 13 to 17, this change means a full review of custom implementations. This is where Umbraco CMS development services can make the process smoother.

Umbraco 13 vs. Umbraco 17: key differences

The Umbraco CMS comparison below shows how the CMS has evolved from version 13 to 17.

Architecture

Umbraco 17 replaces the legacy AngularJS backoffice of version 13 with a modern TypeScript/Web Components architecture. That means that the Umbraco site upgrade will likely entail custom backoffice logic redesign. Moreover, the latest version's extension-first approach means your UI must be re-architected.

Infrastructure and platform baseline

.NET 10 LTS alignment and improved backoffice scalability result in better support for larger editorial teams. In Umbraco 17, you can run a single unified application that scales horizontally, changing how you architect and host it. With an experienced Umbraco development team at your side, you can reap the full benefits of this change.

Content and editor experience    

The new backoffice is more structured and consistent, offering improved navigation and accessibility. On the flip side, the Umbraco 17 upgrade will likely require your editorial team to validate their workflows or even conduct some additional training.

Developer Experience

The developers will benefit from the modernized tech stack, improved tooling and API interaction, as well as operational and infrastructure flexibility. Still, changes to the extension model, removal of deprecated APIs, and variable package compatibility mean that custom code and dependencies must be reviewed.

Pros and cons: staying on Umbraco 13 vs. upgrading to Umbraco 17    

While sticking with version 13 has short-term advantages, Umbraco migration has significant merits in the long run.

What are your options if you're on Umbraco 13?

If your site still runs on Umbraco 13, you can choose among the following options:

• Umbraco migration to supported LTS. It is the best long-term option. This move eliminates the risk of relying on an outdated CMS that will soon become unsupported and, with time, may introduce more and more bottlenecks.

• Staying on 13 with XLTS or Extended Long-Term Support — a paid service offered by Umbraco HQ that provides security patches and compliance updates for older CMS versions even after EOL. It will buy you some time. However, it does not remove tech debt and the associated risks or limitations.

• Do nothing and accept an unsupported state after EOL. While it’s the easiest way, it introduces security and compliance risks. Moreover, it means escalating technical debt and missing out on innovation and performance.

When Should You Upgrade to Umbraco 17 — and When Can You Wait?    

As you can see, the question you face is not why upgrade Umbraco 13, but rather when. The answer depends on:

• Proximity to the end of life. The closer you are to EOL, the greater the associated risks and, consequently, the more urgent the need for an upgrade.

• Dependency readiness. A critical shift to .NET 10 requires your internal libraries and third-party packages to be in line with the new framework. Otherwise, the upgrade can be blocked or cause major stability issues. 

• Ability to adapt to new architecture. Moving from version 13 to 17 means you are adopting a fundamentally re-engineered system. While planning the upgrade, you should factor in time to rebuild custom components for the new backoffice.

• Availability of internal resources. A migration will put extra strain on your in-house team — make sure they are ready to handle it.

All that considered, there may be situations when starting a CMS upgrade ASAP is not a good idea. For instance, if you are planning a major rebuild, but are not ready to kick it off right away. Another case is when current dependencies may hinder migration, and you need time to change them. Or you are unsure how your system will handle the upgrade and need to audit it first.

Not sure which scenario fits your site?

Our Umbraco team will review your setup and tell you exactly what a migration involves — no sales pitch, just a technical assessment.

How to Migrate from Umbraco 13 to 17

We’ve prepared a brief, step-by-step description of the process to help you understand what you’ll need to do.

1. Audit

Start by inventoring your current setup to identify potential blockers. Check for legacy Property editors that do not exist in the newer version's codebase and must be converted. Also, flag deprecated database queries or internal Umbraco APIs. Verify if your essential plugins have stable releases for Umbraco 17.

2. Environment Prep

Prepare for the new tech stack. Install .NET 10 SDK and update IDE: you need Visual Studio 2026 or the latest version of VS Code/Rider. Backup your database and repository. 

3. Incremental Version Steps

As an experienced CMS migration services provider, we recommend an incremental approach to minimize the “migration debt.” First, move from version 13 to 14. Migrate your custom backoffice extensions (JavaScript/TypeScript) here. Once the site is stable on the new UI framework, proceed from 14 to 17. Run the project to trigger the final database schema migrations.

4. Validate Packages

Once the core is updated, fix your dependencies. Update all third-party packages and conduct license migration — move your Umbraco product keys so that the new version of the software can recognize them. Regenerate classes that represent your Umbraco content types in code to ensure they are compatible with the new version.

5. Test Editorial Workflows

Bear in mind that the backoffice was completely rewritten between v13 and v17. Ensure custom dashboards and property editors appear correctly in the new backoffice. Create, save, and publish a complex page to verify that editors render as expected. Test bulk media uploads and focal point cropping.

6. Go-Live

Deploy to a Staging environment first. Put the live site in maintenance mode, take a final database backup, and deploy the .NET 10 build. Clear server-side caches and verify that the version number in the appsettings.json settings file matches the installed version. If there is a discrepancy, the site may refuse to load properly.

Note that a platform upgrade is not the same as a full system upgrade. Moving from .NET 8 to .NET 10 helps with stability, security, and performance. However, that is not enough. A complete upgrade is a structural and functional transformation of the entire application. That means rewriting custom property editors, migrating data structures, and refactoring the frontend. Otherwise, your custom backoffice tools will break, and you won’t be able to take advantage of the Umbraco 17 features.

What to audit before migrating from Umbraco 13 to 17

To make sure you start your journey from version 13 to 17 fully prepared, use our Umbraco upgrade checklist. Here is what you need to focus on:

• Installed packages. List every plugin you use, and check the Umbraco Marketplace to see whether all of them are supported on the latest version. If not, look for a replacement or prepare to custom-build that functionality.

• Custom backoffice extensions. They are written in AngularJS and therefore must be rewritten in TypeScript/Lit for v17.

• Legacy components/Macros. Check for Macros or old Nested Content data types. To avoid data loss, migrate them to the Block List or Block Grid while you are still on Umbraco 13.

• Content workflows. The architectural shift will significantly alter how content actions are executed and tracked. Test if the "human" process of managing the site may break after the migration.

• Third-party integrations. Check external APIs, such as CRMs and payment gateways, to check if their SDKs are compatible with .NET 10.

• Deployment setup. Ensure your hosting is ready for the .NET 10 Runtime and that your CI/CD pipelines can handle the new build requirements.

• Editor-facing functionality. Note which Umbraco 13 features your editors use and check if using the same functionality in version 17 will require extra training.