Umbraco CMS is a free and open source content management system built on .NET, designed to empower developers and content editors alike. It provides a flexible, extensible platform for creating custom websites and digital experiences without sacrificing control or performance. Unlike rigid CMS platforms, Umbraco embraces developer freedom—allowing you to extend functionality through C# code, custom data types, and integrations while maintaining an intuitive backoffice interface for non-technical users. It’s ideal for teams building bespoke web applications, marketing sites, or multi-site installations where content structure and editorial experience matter as much as technical architecture.
Umbraco is not just a tool—it’s a community-driven ecosystem. With comprehensive documentation, active Discord and forum support, and a plugin architecture that supports everything from custom editors to headless APIs, Umbraco enables developers to build solutions tailored to specific business needs without being locked into proprietary constraints.
What You Get
- Easy installation via .NET templates - Install Umbraco with a single command:
dotnet new install Umbraco.Templates followed by dotnet new umbraco --name MyProject, reducing setup time and ensuring consistency across projects.
- Extensible C#-based architecture - Extend functionality using standard .NET Core patterns—create custom content types, editors, and workflows with C# classes, controllers, and views without modifying core code.
- Intuitive backoffice UI - A modern, customizable content editing interface that allows non-technical users to manage pages, media, and structured data with drag-and-drop simplicity.
- Headless CMS capabilities - Expose content via REST and GraphQL APIs to power mobile apps, SPAs, or third-party systems without requiring a traditional server-rendered frontend.
- Full source code access - Open source under MIT license, allowing inspection, modification, and contribution to the core platform for enterprise-grade customization and security audits.
Common Use Cases
- Building a multi-site corporate website with localized content - Organizations manage multiple regional websites (e.g., US, EU, APAC) from a single Umbraco instance using content trees and language variants, with unified editorial workflows.
- Creating a digital marketing portal with custom content types - Marketing teams define bespoke content structures (e.g., product comparison tables, campaign landing pages) using Umbraco’s flexible document types and property editors, without developer intervention.
- Problem: Legacy CMS with rigid templates → Solution: Umbraco’s flexible data modeling - Teams tired of inflexible WordPress themes or Drupal modules use Umbraco to model complex content relationships (e.g., events with speakers, locations, and tickets) using custom doctypes and media libraries.
- DevOps teams managing cloud-hosted content platforms - Developers deploy Umbraco to Azure App Services or Docker containers using official docs, automate CI/CD with GitHub Actions, and scale horizontally while maintaining content consistency across environments.
Under The Hood
Umbraco is a flexible, extensible content management system built with a modular architecture that supports both traditional backend services and modern frontend development. It emphasizes clean separation of concerns, reusable components, and a scalable structure for large-scale content delivery.
Architecture
The system adopts a layered architecture with clear divisions between API services, UI components, and core logic.
- The backend is organized around a management API layer that exposes content and configuration endpoints through controllers and base classes.
- The frontend follows a package-based structure with well-defined exports, supporting plugin-style extensions via manifests and context APIs.
- Design patterns such as dependency injection, controller composition, and component-based UI development promote decoupling and testability.
- A centralized extension registry and event-driven architecture enable runtime customization and dynamic behavior registration.
Tech Stack
The project leverages modern technologies for both backend and frontend development, with a strong emphasis on web standards.
- Built primarily in C# for backend services and TypeScript/JavaScript for the frontend, using Lit web components and a modular package system.
- Integrates with RxJS for reactive programming, Monaco Editor for rich text editing, and Tiptap for content formatting capabilities.
- Development tools include Vite for fast builds, TypeScript for type safety, and ESLint for code quality enforcement.
- Testing is supported through Playwright for end-to-end validation and Web Test Runner for component-level testing.
Code Quality
The codebase reflects a mature development approach with consistent patterns and strong testing practices.
- Comprehensive test coverage and linting configurations ensure code reliability and maintainability across modules.
- Error handling is implemented through widespread use of try-catch blocks and custom exception types for better diagnostics.
- Code consistency is maintained through established conventions and architectural patterns, though some technical debt exists in controller complexity.
What Makes It Unique
Umbraco distinguishes itself through its deeply integrated and extensible management API, tailored for content-rich CMS environments.
- The Management API provides a domain-driven REST interface that enables rich content operations within a broader CMS ecosystem.
- It uniquely balances extensive functionality with modular design, supporting flexible backoffice extensibility and runtime customization.
- The system’s ability to support plugin-style extensions through manifests and context APIs sets it apart from more rigid CMS architectures.