What is Umbraco? A 2026 guide to the open-source .NET CMS, its licensing, products and fit

Umbraco is a content management system (CMS) for Microsoft .NET, and its core is free under the MIT license. It runs on ASP.NET Core, stores content in SQL Server or SQLite, and gives editors a browser-based back office while giving developers full control over content models and code. The project is led by Umbraco HQ, a company headquartered in Odense, Denmark, which funds development by selling hosting (Umbraco Cloud), commercial add-ons and support.

In practice, Umbraco sits between a simple website builder and a large enterprise digital experience platform. Teams pick it when they want a .NET codebase they own, a clean editing experience and no per-seat license fee for the core CMS. This guide covers what Umbraco is as of October 2026: history and licensing, architecture, the commercial products around it, the release cycle, who uses it, and when it is or is not a good fit.

Umbraco in one table

A short history and the licensing model

Danish developer Niels Hartvig started building Umbraco around 2000 and released it as open source in 2004, according to published histories of the project; the company itself gives 2003 as its founding year on its About page. The CMS has been fully under the MIT license since version 4.5. Version 5, an attempted rewrite, was dropped in 2012, and the project continued on the version 4 code line, which became Umbraco 6, 7 and 8 on .NET Framework.

The big technical shift came with Umbraco 9 in 2021, which moved the CMS to ASP.NET Core. In the same year, Swedish software investor Monterro acquired a majority stake in Umbraco HQ, as the company announced on its blog. Umbraco HQ describes itself as having 140+ employees and a community of more than 250,000 developers and users.

Is Umbraco open source?

Yes, without qualification. The full CMS source is on GitHub under the MIT license, which allows commercial use, modification and private hosting without paying anything or publishing your own code. There is no “community edition” with features held back: the free CMS is the same CMS that runs on Umbraco Cloud. The commercial products are separate packages and services built around it.

How Umbraco works: the architecture

A .NET application you own

An Umbraco site is a normal ASP.NET Core project. You create it with dotnet new umbraco, add NuGet packages, write C# for business logic and Razor views for templates, and deploy it like any other .NET web app. Umbraco 17 and 18 require .NET 10 and run on Windows, Linux or macOS, behind IIS, Kestrel or in containers, per the requirements page.

This is the main difference from SaaS CMS products: the CMS is a library inside your application, not a separate service you call. You can add your own controllers, background jobs, database tables and integrations in the same codebase.

Content model: Document Types and Data Types

Developers define the structure. A Document Type describes a kind of page or item (Article, Product, Event) with its properties, and each property uses a Data Type such as text, rich text, media picker or a block editor. Editors then create content inside that structure. This is why Umbraco sites tend to stay consistent over the years: editors can only enter content in the shapes the model allows.

The back office

The back office is the editor interface at /umbraco. Since Umbraco 14 it has been rebuilt as a Web Components application using Lit and TypeScript, and it talks to the server through the Management API, a REST API documented with OpenAPI that external apps can also use with OpenID Connect, according to the Management API documentation. Since Umbraco 16 the rich text editor is based on Tiptap.

Features editors use daily include tree-based content, language variants, scheduled publishing, version history with rollback, user groups with granular permissions, redirect tracking when URLs change, and media management with image cropping.

Block Grid and Block List

Modern Umbraco page building is done with block editors. The Block Grid lets editors place developer-defined blocks (hero, text and image, card list, form) into a grid layout with areas and column spans. Block List is the simpler, linear version. Developers decide which blocks exist and where they can be used, so editors get layout freedom without breaking the design system. Umbraco 18 adds Elements, a library of reusable content items that live outside the page tree.

Headless and hybrid delivery

Umbraco can render HTML itself, serve content as JSON, or do both from the same installation. The Content Delivery API is built in and opt-in: enable it with Umbraco:CMS:DeliveryApi:Enabled and .AddDeliveryApi(), and any front end (Next.js, a mobile app, a kiosk) can query published content and media. It supports preview, protected member content, output caching and, from Umbraco 18, opt-in typed OpenAPI schemas per content type. Webhooks notify other systems when content changes.

We used this on the Omoda Denmark site, where headless Umbraco content is rendered by Next.js and one monorepo serves several differently designed sites.

Data, cache and search

Content, users and settings live in the database, media in a file system or blob storage, and published content is served from HybridCache, a lazy-loaded cache introduced in Umbraco 15. Built-in search, Examine, is based on Lucene. We cover this in detail in where does Umbraco store data.

Umbraco products and how Umbraco makes money

The CMS is free. Umbraco HQ’s revenue comes from products and services around it. Names and pricing models below are taken from umbraco.com in October 2026; check the pricing page for current figures.

Umbraco also runs a partner program for agencies. Its Q1 2026 product update adds Umbraco.AI for governed AI features in the back office, an MCP integration and a new pluggable Umbraco Search package, with Examine remaining the default provider.

Umbraco Cloud vs self-hosting

Umbraco’s own comparison is a fair summary:

Cloud suits agencies and teams that want to focus on the site rather than servers. Self-hosting suits organizations with an existing cloud platform, strict network or data residency rules, or high-traffic setups that need custom scaling. We run both: Disctopia and EducatedOn are on Umbraco Cloud, while Ben-Gurion University’s ~80,000-page site runs self-hosted on AWS ECS Fargate with Amazon RDS and S3, and Alliant’s platform runs on Azure with Blob Storage, a load balancer and Datadog monitoring.

Release cadence: LTS and STS

Umbraco ships a new major version about every six months. The support policy defines three phases: six months of active development with minor releases about every six weeks, then a support phase, then a security-only phase. Short-term support (STS) majors get about a year in total; long-term support (LTS) majors get three years. A new LTS follows each .NET LTS release.

For most organizations the rule is simple: build on the current LTS and upgrade from LTS to LTS. Our Umbraco 13 vs 17 comparison covers that decision, and the Umbraco 8 to 17 upgrade guide covers older sites.

Who uses Umbraco

Umbraco is a niche product by raw numbers. Web technology surveys put it at under 0.1% of all websites in October 2026, far behind WordPress. Its strength is in mid-sized and large organizations rather than small blogs. The case studies Umbraco publishes come mostly from the UK, Northern Europe, the US and Australia, and many are public sector bodies, universities, membership associations, financial firms and manufacturers.

Umbraco’s case study library names, among many others, Primark, Thames Water, Die ZEIT, Ahold Delhaize, the Royal Navy, the British Army, Renault Group UK, Volvo Car Retail Solutions, Edmond de Rothschild and Newcastle International Airport.

Projects we have delivered on Umbraco show the range:

• Ben-Gurion University: about 80,000 pages, around 1,000 editors, Lucene search across more than ten search pages and a daily import of 15,000+ staff profiles. A sister student and staff portal runs on the same Umbraco setup.
• Alliant: a US insurance brokerage’s family of websites rebuilt on one modular, multi-site Umbraco codebase, with Okta sign-in for editors and Umbraco Forms workflows feeding Eloqua.
• Auto.co.il: the third generation of a major Israeli car portal on Umbraco 15 and .NET 9, with about 100,000 records migrated from a legacy CRM and WCAG accessibility work.

What is Umbraco used for?

Typical use cases, in rough order of how often we see them:

1. Corporate and institutional websites with many editors, sections and permission rules.
2. Multi-site and multi-language estates, where several brands or regions share one codebase. See our guide to Umbraco multi-site architecture.
3. Portals and member areas with login, personalized content and integrations with line-of-business systems.
4. Headless content hubs that feed web front ends, apps and other channels through the Delivery API.
5. Content-rich commerce with Umbraco Commerce or an external store connected to Umbraco content.

When Umbraco is a good fit

• Your team or vendor works in C# and .NET, or the site must integrate with .NET, Azure or Microsoft identity systems.
• You need a structured content model that stays tidy as hundreds of editors work on it.
• You want to own the code and data, host where you like and avoid per-user CMS license fees.
• You need both rendered pages and a headless API from one system.
• You run several sites that should share components and editors.

When Umbraco is not the right choice

• A small brochure site with no developer budget. Umbraco needs a developer to set up the content model and templates. A hosted site builder or WordPress with a theme is cheaper to launch.
• You want a large marketplace of ready-made plugins and themes. Umbraco’s package ecosystem is much smaller than WordPress’s, and many features are built rather than installed.
• Your organization has no .NET skills and no plans to hire them. Hosting, upgrades and fixes all need .NET experience.
• You want a fully managed SaaS where upgrades are never your concern. Umbraco Cloud automates minor and patch upgrades, but major upgrades still involve code work every few years.

If you are comparing the two most common options, read our Umbraco vs WordPress comparison.

How to get started

1. Install the .NET 10 SDK and run dotnet new install Umbraco.Templates, then dotnet new umbraco -n MySite. Use SQLite locally to start.
2. Model a few Document Types and a Block Grid before designing templates. The content model is the hardest part to change later.
3. Decide on rendering (Razor, headless or hybrid) and hosting (Cloud or self-hosted) early, because they shape deployment.
4. Plan your upgrade path from LTS to LTS.

If you want a head start, our free umContentCreator package, which has a release line for Umbraco 17, adds AI text and image generation to the back office. Our free OskiStarterKit installs prebuilt page types, Block Grid layouts, menus and SEO fields, but its current 4.x line targets Umbraco 13, so it suits existing 13 sites rather than new builds on 17. For a full build, migration or extra capacity, our Umbraco development team is a registered Umbraco Partner with more than ten years of Umbraco and .NET work.