Introduction

Modern web development is moving toward faster, more interactive, and scalable applications. Developers want the flexibility to choose between server-side rendering and client-side rendering without rewriting their applications.

Blazor United in .NET 10 is designed to solve this exact problem. It combines the power of Blazor Server and Blazor WebAssembly into a single unified model. This allows developers to build flexible, high-performance web applications using C# instead of JavaScript.

In this article, we will understand Blazor United in simple words, explore how it works, and see how it improves developer productivity and application performance.

What is Blazor United?

Blazor United is a unified web framework in .NET 10 that allows developers to use multiple rendering modes in the same application.

Instead of choosing between:

You can now use both together in a single app.

This means your application can:

This hybrid approach gives the best of both worlds.

Understanding Rendering Modes in Blazor

To understand Blazor United, we need to first understand the existing rendering modes.

1. Blazor Server

Blazor Server runs your application logic on the server.

How it works:

Example:

<h3>Hello from Server</h3>
<button @onclick="Increment">Click me</button>

@code {
    int count = 0;
    void Increment() => count++;
}

Benefits:

Limitations:

2. Blazor WebAssembly

Blazor WebAssembly runs directly in the browser.

How it works:

Benefits:

Limitations:

How Blazor United Combines Both

Blazor United allows you to mix both rendering modes seamlessly.

1. Server-Side Pre-rendering

The app first loads using server rendering.

Why this matters:

2. Automatic Client-Side Activation

After loading, the app can switch to WebAssembly.

Why this matters:

3. Per-Component Rendering Modes

In Blazor United, each component can choose its rendering mode.

Example:

<Counter @rendermode="InteractiveWebAssembly" />

This means:

4. Shared Codebase

You don’t need separate projects anymore.

Why this matters:

Key Features of Blazor United in .NET 10

1. Flexibility in Rendering

Developers can choose how each part of the app runs.

Impact:

2. Improved SEO Support

Server-side rendering improves SEO significantly.

Impact:

3. Better Performance

By combining both modes:

4. Simplified Development

Single project structure reduces complexity.

Impact:

5. Modern Web Experience

Blazor United enables SPA-like experience with server benefits.

Impact:

Real-World Example

Imagine building an e-commerce website.

With Blazor United:

This creates a balanced and optimized application.

When Should You Use Blazor United?

Blazor United is ideal for:

Limitations to Consider

Summary

Blazor United in .NET 10 is a powerful evolution of the Blazor framework that combines server-side and client-side rendering into one unified model. It allows developers to build flexible, high-performance web applications using C#, while improving SEO, performance, and user experience. By enabling per-component rendering and shared codebases, it simplifies development and makes modern web applications more efficient and scalable.