Blazor

Blazor Tutorials: Build Interactive Web Apps in C#

Blazor is the part of ASP.NET Core that lets you build interactive web UIs with C# and Razor components instead of JavaScript. These Blazor tutorials use the Blazor Web App template on .NET 10, with complete code you can run.

Blazor sits on top of ASP.NET Core, so it helps to know the ASP.NET Core basics and solid C# first.

By Bijay Kumar, 13-time Microsoft MVP · Updated October 2026

What Is Blazor?

A Blazor app is built from Razor components: .razor files that mix HTML markup with C# code. The same component model works for server-rendered pages, fully interactive pages and even native desktop and mobile apps through Blazor Hybrid.

  • One language end to end. Your UI logic, validation rules and models are all C#, so you can share code between the browser and the server.
  • Part of ASP.NET Core. Dependency injection, configuration, logging and authentication work the same way as in any ASP.NET Core app.
  • A natural next step for Web Forms teams. Components, events and data binding feel familiar if you’ve built Web Forms pages and user controls.

Blazor Render Modes Explained

Since .NET 8, one Blazor Web App can mix four render modes. You pick a mode per component or for the whole app, and interactive modes prerender on the server by default for a fast first paint.

Render modeWhere it runsInteractiveGood for
Static Server (static SSR)ServerNoContent pages, forms that post back, SEO-friendly pages
Interactive ServerServer, over a SignalR connectionYesInternal line-of-business apps, the closest fit for Web Forms teams
Interactive WebAssemblyBrowser (the .NET runtime runs in WebAssembly)YesApps that should keep working with less server load
Interactive AutoServer first, then the browser once the app bundle is downloadedYesFast first load plus client-side speed afterwards

Not sure which to pick? Start with Interactive Server for internal business apps. It needs no separate client project, and your component code can call the database directly. Switch individual pages to WebAssembly or Auto later if you need them.

Blazor Learning Path

Work through these steps in order. Each step’s tutorials are linked here as they’re published.

  1. Create your first Blazor Web App

    Create a project with dotnet new blazor on the .NET 10 SDK, run it, and learn how Razor components, routing and layouts fit together.

  2. Components, parameters and events

    Build reusable components, pass data in with parameters and raise events back to the parent. Delegates and events in C# are the foundation here.

  3. Forms, validation and data grids

    Use EditForm with data annotations for validation, and QuickGrid to show tables of data. QuickGrid is the usual replacement for a Web Forms GridView.

  4. Call APIs and work with data

    Call an ASP.NET Core Web API from a component with HttpClient, or use EF Core directly in Interactive Server apps.

  5. Authentication and authorization

    Sign users in with ASP.NET Core Identity or Microsoft Entra ID, and protect pages and components with AuthorizeView and the [Authorize] attribute.

  6. Move Web Forms pages to Blazor

    Map Web Forms concepts (pages, user controls, code-behind, ViewState) to Blazor components, and migrate one page at a time.

Before You Start

Brush up on these C# topics first. Blazor components lean on them constantly.

Frequently Asked Questions

Is Blazor worth learning in 2026?

Yes, especially if you already know C#. Blazor is part of ASP.NET Core and gets new features in every .NET release, and many US companies use it for internal business apps and for replacing old Web Forms systems.

Blazor Server or Blazor WebAssembly: which should I use?

Since .NET 8 you don’t have to choose for the whole app. A Blazor Web App can use Interactive Server, Interactive WebAssembly or Interactive Auto per component. Interactive Server is the simplest place to start; WebAssembly runs in the browser and reduces server load.

Do I need JavaScript to use Blazor?

No. You can build complete apps in C#. When you need a browser API or an existing JavaScript library, Blazor’s JavaScript interop lets you call JavaScript from C# and C# from JavaScript.

Can Blazor replace ASP.NET Web Forms?

Yes. Web Forms isn’t available in ASP.NET Core, and Blazor is the closest match: reusable components, event handlers and data binding in C#. Most teams migrate one page at a time.

Which .NET version should I use for Blazor?

Use .NET 10, the current long-term support release, supported until November 14, 2028. See .NET versions and support dates.