# Blazor — Build Interactive Web UIs with C# Instead of JavaScript

> Microsoft's web framework for building interactive client-side and server-side web applications using C# and .NET instead of JavaScript.

## Install

Save as a script file and run:

# Blazor — Build Interactive Web UIs with C#

## Quick Use
```bash
dotnet new blazor -o MyApp
cd MyApp
dotnet run
```
Open `https://localhost:5001` to see the app running.

## Introduction
Blazor is a framework within ASP.NET Core that lets developers build interactive web UIs using C# instead of JavaScript. It supports both server-side rendering with real-time SignalR connections and client-side execution via WebAssembly, giving teams a single-language stack for full-stack web development.

## What Blazor Does
- Renders interactive UI components written in C# and Razor syntax
- Runs client-side in the browser via WebAssembly (Blazor WASM) or server-side with SignalR (Blazor Server)
- Supports hybrid rendering modes mixing SSR, streaming, and interactivity per component
- Integrates with the full .NET ecosystem including EF Core, authentication, and dependency injection
- Enables code sharing between client and server with shared .NET libraries

## Architecture Overview
Blazor uses a component model where each `.razor` file defines a reusable UI component with C# logic and HTML markup. In Server mode, UI events travel over a SignalR WebSocket to the server, which computes diffs and sends minimal DOM updates back. In WASM mode, the .NET runtime runs directly in the browser sandbox. .NET 8+ introduced unified rendering that lets each component choose its own render mode.

## Self-Hosting & Configuration
- Install the .NET SDK (8.0+) from `dotnet.microsoft.com`
- Create a project with `dotnet new blazor` for the unified template
- Configure render modes in `App.razor` using `@rendermode` directives
- Deploy as a standard ASP.NET Core app behind Nginx, IIS, or in a container
- Publish WASM apps as static files to any CDN or static host

## Key Features
- Full-stack C# eliminates the need for a separate JavaScript framework
- Component-based architecture with strong typing and IntelliSense
- Hot reload during development for rapid iteration
- Built-in form validation, authentication, and authorization
- AOT compilation for WebAssembly improves runtime performance

## Comparison with Similar Tools
- **React** — JavaScript ecosystem with larger community; Blazor uses C# with smaller but growing ecosystem
- **Angular** — TypeScript-based with similar component model; Blazor integrates natively with .NET backend
- **Svelte** — Compiler-based approach with smaller bundles; Blazor WASM has larger initial download
- **Leptos** — Rust-based WASM framework; Blazor has broader enterprise adoption and tooling

## FAQ
**Q: Does Blazor replace JavaScript entirely?**
A: For most UI scenarios yes, but you can still call JavaScript via JS interop when needed for browser APIs or third-party JS libraries.

**Q: How large is the Blazor WASM download?**
A: The initial download is around 2-5 MB for the .NET runtime, but subsequent loads are cached. AOT compilation and trimming can reduce this.

**Q: Can Blazor be used for mobile apps?**
A: Yes, Blazor Hybrid with .NET MAUI lets you embed Blazor components in native iOS, Android, and desktop apps.

**Q: Is Blazor production-ready?**
A: Yes, Blazor has been stable since .NET Core 3.1 and is used in production by many enterprises.

## Sources
- https://github.com/dotnet/aspnetcore
- https://learn.microsoft.com/aspnet/core/blazor

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Source: https://tokrepo.com/en/workflows/asset-93cad652
Author: Script Depot