An Umbraco 8 upgrade starts with two decisions: which supported version to target, and how to preserve the content and functionality your website already depends on.

Umbraco 8 reached end of life on 24 February 2025. For organisations planning an upgrade now, Umbraco 17 LTS provides a destination with support scheduled until 27 November 2028.

The route depends on your content structure, packages, custom code, integrations and hosting. Some projects suit a staged migration. Others benefit from a new Umbraco application that retains selected content and features.

Phases’ Umbraco upgrade services cover the assessment, migration, development, testing and release work needed for either approach.

What does Umbraco 8 end of life mean for your website?

Your website can continue operating after end of life. However, standard security updates and maintenance from Umbraco HQ have ended.

That changes how you plan ongoing support, package compatibility and future development.

Start by reviewing the CMS alongside its hosting, integrations and custom functionality. This establishes what can be retained and what needs updating, helping your team define an upgrade scope before committing to delivery dates.

Which Umbraco version should you upgrade to?

For organisations seeking a longer support period, Umbraco 17 LTS is the main destination to assess. It runs on .NET 10 LTS, with support scheduled until 27 November 2028.

Umbraco 13 reaches end of life on 14 December 2026. It may form part of a staged migration, but a new upgrade plan should define a supported destination beyond that date.

The decision should account for package compatibility, custom backoffice extensions, content editors, integrations and hosting requirements.

How Phases plans an Umbraco upgrade

We begin with the existing website and the people who manage it.

  1. Assess the implementation. Review content models, packages, custom code, integrations, hosting and editorial requirements.

  2. Choose the migration approach. Identify what can be retained, adapted, replaced or rebuilt.

  3. Rehearse and validate. Test migrated content, media, forms, member access, search and editor workflows in a separate environment.

  4. Prepare the release. Map URLs and redirects, check metadata, agree the deployment window and document recovery steps.

Examples from our Umbraco migration work

These completed projects illustrate different migration approaches. Their destination versions reflect decisions made at the time.

NYC Votes: Umbraco 8 to 13

Phases migrated legacy content components, adapted custom code and updated search and Salesforce integration while maintaining public access.

Read about the NYC Votes Umbraco 8 to 13 upgrade.

In-Kommuner: Content migration with uSync

The project involved migrating an Umbraco 7 website to Umbraco 13 using uSync, transferring content and settings while updating the frontend.

Green Key: Redevelopment across multiple brands

Green Key’s platform was rebuilt from Umbraco 7 into Umbraco 10 in 2023. The work included multilingual content, Podio integration, hotel data feeds and maps.

Selecting Umbraco 13 for Long-Term Support

We worked with an organisation that had just received a new site on Umbraco 15 from another agency. The site was delivered with more than 300 static pages, which meant editors had almost no control over content. Managing updates was slow and difficult.

Our review showed the site would work better on Umbraco 13 LTS, so that became the recommendation. This Umbraco version offered long-term support, a proper content structure, and an editor-friendly back office. The team gained flexibility, and the business gained a platform built to last.

This project shows why the newest release is not always the right answer. The stronger choice is the one that combines stability, support, and ease of use.

Should you migrate the existing application or build a new one?

A staged migration is worth assessing when the existing content structure and functionality still serve the organisation well.

A new application may suit a website that needs substantial changes to its content models, editor workflows or custom features. Selected content and media can then be migrated into the agreed structure.

For Umbraco 8 websites, content migration and application development need separate assessment. Templates, custom code and packages require review because modern Umbraco uses a different underlying application architecture.

Our staged Umbraco database migration guide explains one approach used on an older website.

Plan your Umbraco upgrade with Phases

An Umbraco upgrade is a strategic decision about how your organisation manages content, protects integrations, and prepares for the future. Recognized as the best Gold Partner by Umbraco in 2021, we earned that position by ensuring every build delivered three essentials:

  • Content, SEO, and integrations remain intact.

  • Editors gain a more efficient and reliable platform.

  • The business operates on a foundation supported for years to come.

At Phases, we bring that assurance. Our team includes Umbraco Experts, MVPs and Masters who actively contribute to the platform. As a Gold Contributing Partner, we have direct visibility into the roadmap and close collaboration with Umbraco HQ.

Some organisations will move to 13 this year. Others will wait and plan for Umbraco 17. Both are sound strategies. The difference lies in how the upgrade is managed. Whether it's predictable, safe, and aligned with long-term goals.

If you are considering the future of your Umbraco site, now is the time to plan the path forward.

Get Your Umbraco Audit 

  • Questions about upgrading Umbraco 8

  • Can an Umbraco 8 website be migrated to Umbraco 17?

    Yes. Existing content can be migrated to a newer Umbraco implementation. Templates, custom code, packages and backoffice extensions need assessment to establish the migration scope.

  • Do we have to rebuild the whole website?

    The scope depends on the implementation. Content, media and selected functionality can often be retained. The assessment identifies what can be migrated, adapted or rebuilt.

  • Can we preserve our URLs?

    Existing URLs should be retained where possible. Where URLs change, prepare redirect mappings and update internal links, canonical tags and the sitemap.

  • Will the website remain available during the upgrade?

    Development and testing can take place separately while the existing website serves visitors. Any content freeze or interruption during the final release should be agreed during deployment planning.

  • What determines the cost and duration?

    Content structure, custom code, package compatibility, integrations, member functionality, hosting and testing requirements determine the scope. A technical assessment provides the basis for an estimate.

Related reading

This article was published on 23 September 2025, when Umbraco 13 was the current LTS and Umbraco 17 was still ahead. Preserve that planning context when reading the body.

Current official guidance: Umbraco 8 cannot be upgraded directly to Umbraco 17. Content is typically migrated from Umbraco 8 onto a modern .NET project (commonly via Umbraco 10 database migrations), then upgraded along the supported major path to the current LTS. Custom ASP.NET code and templates must be reimplemented for ASP.NET Core. Confirm the latest path in Umbraco’s documentation.