Is it possible to build modern, interactive web applications in C# and .NET without using JavaScript? Microsoft proves that it is – thanks to Blazor. This relatively young framework is gaining increasing popularity among .NET developers, offering an approach that truly changes the rules of the game.
In this article, I’ll explain what Blazor is, why many people call it a game changer, and I’ll show simple examples of how it works. You’ll also learn how Blazor simplifies web development and what opportunities it offers to those who decide to explore it further.
What Is Blazor?
Blazor is a modern framework for building interactive web applications using C# and the .NET platform instead of JavaScript. Simply put – it allows you to write both front-end code (running in the browser) and back-end logic in one language, which greatly simplifies application development.
Blazor was created by Microsoft as part of ASP.NET Core and uses Razor syntax to define UI components. The name Blazor is a wordplay combining “Browser” and “Razor”, highlighting its web nature and the use of Razor-based UI.
The key concept in Blazor is the component – a piece of UI (a page, form, button, etc.) with its own logic. A component is written in a `.razor` file, where HTML and C# coexist seamlessly thanks to Razor.
Below is a simple example of a Blazor component showing a button that increments a counter:
@page "/"
<h1>Welcome to Blazor!</h1>
<button class="btn btn-primary" @onclick="IncrementCount">Click me</button>
<p>Counter: @currentCount</p>
@code {
private int currentCount = 0;
private void IncrementCount()
{
currentCount++;
}
}This component corresponds to the root page of the application (@page "/"). Inside, you’ll see standard HTML tags (<h1>, <button>, <p>) as well as Blazor-specific constructs:
• @onclick="IncrementCount" binds a C# method to the click event,
• @currentCount injects the current C# variable value into the HTML.
When the user clicks the button, the `IncrementCount` method updates the counter, and Blazor automatically refreshes the relevant part of the DOM. No JavaScript is needed – the entire interaction logic is written in C#.
This component-driven approach is similar to frameworks like React or Angular, but here everything happens in a unified .NET stack.
How Does Blazor Work? Blazor Server vs Blazor WebAssembly
Now that you know Blazor can run .NET code in the browser, the next question is: how is that possible?
Microsoft offers two main hosting models:
• Blazor WebAssembly (WASM)
In this model, the entire application (plus a minimal .NET runtime) is downloaded to the browser and runs in the WebAssembly sandbox.
• C# code is compiled to WebAssembly or interpreted through it,
• the application runs fully on the client side,
• it can work offline,
• communication with the server happens only when needed (e.g., data fetch).
This feels like a typical SPA running locally.
Advantages:
• Offline support
• Uses client’s CPU/resources
• Highly responsive interactions
Drawbacks:
• Initial download size may be larger
• First load can be slower on weak devices or connections
• Blazor Server
In this model, the app runs entirely on the server, and the browser acts as a thin client connected via SignalR/WebSockets.
• Every user action is sent to the server,
• The C# logic executes there,
• Only UI diffs are sent back to the browser.
The result: a fully interactive UI with almost no JavaScript and extremely small payload.
Advantages:
• Very fast initial load
• Full .NET power available on the server
• Works even on older devices/browsers
Drawbacks:
• Requires a stable network connection
• Scaling can be more complex (server maintains session state)
Both models use the same Blazor components – the difference is only where the code executes.
There’s also Blazor Hybrid (via .NET MAUI), allowing Blazor components to run in desktop and mobile apps.
Why Blazor Is a True Game Changer
Here are the reasons why Blazor feels revolutionary to so many .NET developers:
• One Language, One Codebase (Full-Stack C#)
You can write *everything* in C#, both front end and back end. No switching between ecosystems, no constant juggling between C# and JavaScript.
This is huge for productivity, debugging, and overall developer experience.
• Shared Models and Logic
Validation, domain models, business logic – all of that can be shared between server and client.
No code duplication, no inconsistencies between backend C# and frontend TypeScript.
• Full Power of the .NET Ecosystem in the Browser
Blazor integrates seamlessly with the entire .NET ecosystem:
-Entity Framework Core
-identity/auth
-logging
-LINQ
-ML.NET
You can leverage familiar tools and libraries inside a browser app – something that wasn’t possible before WebAssembly.
• High Performance with WebAssembly
Blazor WebAssembly compiles C# to WebAssembly – a fast, low-level, near-native binary format.
This means:
-very fast computations
-responsive UI
-minimal JS glue code
• Offline Apps & PWA
With Blazor WebAssembly:
-the app can run offline,
-can be installed as a PWA,
-can store data locally and sync when back online.
• Component-Based UI Architecture
Blazor uses reusable components:
-encapsulated logic
-parameters
-events
-child components
-state management
This helps keep the app structured, maintainable, and modular.
• Strong Backing From Microsoft + Growing Community
Blazor receives continuous improvements with every .NET release (especially in .NET 7 and .NET 8).
The community is growing fast, and vendors provide mature UI component libraries (Telerik, Syncfusion, MudBlazor…).
Blazor is no longer an experiment – it’s a serious web technology.
Summary
Blazor is one of the most exciting web technologies in the .NET ecosystem. It allows C# developers to enter the world of front-end development without learning JavaScript, which is a genuine breakthrough.
Thanks to:
-a unified technology stack,
-WebAssembly performance,
-component-driven architecture,
-strong Microsoft support,
Blazor simplifies many aspects of web development and opens new possibilities — from SPA apps, to PWAs, to hybrid desktop/mobile apps.
As of .NET 8, Blazor has matured significantly, and more and more companies are adopting it in production.
If you’re a C# developer (beginner or intermediate), Blazor is absolutely worth trying.
A simple “Counter” app is enough to feel the magic: interactive UI powered entirely by C#.
And if you want to learn Blazor properly and avoid common pitfalls, there are full online courses such as Blazor School, designed to help .NET developers master real-world Blazor development.
Blazor is a true game changer bringing .NET to the front end on a scale never seen before.
Will it become as popular as React or Angular? Time will tell — but many developers already believe it’s the future of .NET web development.
If you're starting a new project or modernizing an old one, Blazor is definitely worth keeping an eye on.
