What is Blazor?

Blazor is a modern web framework developed by Microsoft that allows developers to build interactive web applications using C# and .NET instead of JavaScript. It supports two hosting models.

  1. Blazor Server: The app runs on the server, and UI updates are sent via SignalR.
  2. Blazor WebAssembly (WASM): The app runs in the browser using WebAssembly, enabling a fully client-side experience.

Blazor provides a component-based architecture similar to React or Angular, but developers write everything in C# instead of JavaScript.

How does Blazor differ from Traditional ASP.NET (MVC/WebForms)?

Feature Blazor ASP.NET MVC ASP.NET WebForms
Language C# (Frontend & Backend) C# (Backend) + JavaScript C# (Backend) + JavaScript
UI Approach Component-based UI Razor Views (MVC-based) Page & Control-based UI
Rendering Client-side (WebAssembly) or Server-side (SignalR) Server-side Server-side
State Management Built-in state management (via Cascading Parameters, Dependency Injection, etc.) Requires TempData, ViewData, Session ViewState, Session, Cache
JavaScript Dependency Minimal (only when needed via JSInterop) High (for AJAX, interactivity) High (PostBacks & JavaScript)
Performance Faster for real-time apps (Blazor Server) & fully offline support (Blazor WebAssembly) Requires page reloads & API calls for interactivity ViewState-heavy, causing performance issues
Modern Development Uses Razor components, dependency injection, and WebAssembly Follows the MVC pattern but relies on JavaScript for interactivity Uses PostBacks and ViewState, which are outdated
Mobile-Friendly Better support for responsive UI Needs additional frameworks like Bootstrap Less mobile-friendly (due to ViewState)


Key Advantages of Blazor Over Traditional ASP.NET

When to Use Blazor?