Angular

Angular + WebAssembly or Angular + Blazor Interop: When and How

As web applications become more complex, developers are always looking for ways to improve performance, flexibility, and reusability.
Two modern technologies — WebAssembly (WASM) and Blazor — have opened up new possibilities for integrating .NET and Angular together.

This article explains when and how to use Angular with WebAssembly or Angular with Blazor interop, depending on your project needs.

1. Understanding the Key Technologies

Before comparing them, let’s first understand what each technology does.

a) Angular

Angular is a powerful front-end framework built on TypeScript, designed for building dynamic, single-page web applications (SPAs).
It handles UI, routing, forms, and state management on the client side.

b) WebAssembly (WASM)

WebAssembly is a binary instruction format that runs directly in the browser at near-native speed.
It allows languages like C#, C++, or Rust to run on the web, alongside JavaScript.

Key benefits

  • High performance (near-native execution)

  • Runs inside modern browsers securely

  • Works with JavaScript and frameworks like Angular

c) Blazor

Blazor is a .NET-based framework from Microsoft that can run C# code in the browser using WebAssembly (Blazor WebAssembly) or on the server (Blazor Server).
It allows developers to build full-stack web apps using C# instead of JavaScript.

2. The Integration Scenarios

When combining Angular with .NET technologies, two popular approaches appear:

  1. Angular + WebAssembly

  2. Angular + Blazor Interop

Let’s explore what they mean and when to use each one.

3. Angular + WebAssembly

When to Use

This combination is ideal when you need performance-heavy logic or native speed inside an Angular app.

You might use it when:

  • You have complex mathematical or graphics operations

  • You want to reuse existing C++/C# logic

  • You need fast data processing in the browser

  • You want to avoid sending large computations to the server

How It Works

  1. Your Angular app runs as usual in the browser.

  2. You compile C++ or C# code into WebAssembly (.wasm).

  3. The Angular app loads the .wasm file and calls its exported functions using JavaScript interop.

Example: Calling WebAssembly from Angular

// wasm.service.ts@Injectable({ providedIn: 'root' })
export class WasmService {
  private wasm: any;

  async loadWasm() {
    const response = await fetch('assets/myModule.wasm');
    const buffer = await response.arrayBuffer();
    const module = await WebAssembly.instantiate(buffer);
    this.wasm = module.instance.exports;
  }

  calculateSum(a: number, b: number): number {
    return this.wasm.add(a, b);
  }
}

C++ Example

extern "C" {
    int add(int a, int b) {
        return a + b;
    }
}

Compile this using Emscripten to generate myModule.wasm.

Benefits

  • Super fast for CPU-intensive tasks

  • Works with any modern browser

  • Keeps Angular UI responsive

Limitations

  • Harder debugging and tooling

  • Not ideal for basic web logic

  • Requires compiling and managing .wasm files

4. Angular + Blazor Interop

When to Use

This combination is useful when your team wants to use C# and .NET logic inside an Angular app — for example:

  • Reusing existing .NET libraries or validation logic

  • Slowly transitioning from Angular to Blazor

  • Building hybrid apps using Angular for UI and Blazor for business logic

How It Works

  1. Blazor runs on WebAssembly or Server mode.

  2. Angular runs in the browser (TypeScript).

  3. You create a JavaScript interop layer where Angular and Blazor share data and call each other.

Architecture Overview

[Angular UI]  ←→  [JavaScript Interop]  ←→  [Blazor Components (.NET)]

  • Angular handles UI, routing, forms

  • Blazor handles C# logic, API calls, or complex operations

  • Both communicate through interop calls

Example: Angular Calling Blazor Component

You can embed a Blazor component inside an Angular app using an iframe or custom element.

Step 1: Build a Blazor Component

<h3>Weather Forecast</h3>
<p>@Message</p>

@code {
    [Parameter] public string Message { get; set; } = "Sunny Day!";
}

Step 2: Expose as a Web Component

In Program.cs (Blazor WebAssembly):

using Microsoft.AspNetCore.Components.WebAssembly.Hosting;
using Microsoft.AspNetCore.Components.Web.Extensions;

var builder = WebAssemblyHostBuilder.CreateDefault(args);
builder.RootComponents.RegisterCustomElement<WeatherForecast>("weather-component");
await builder.Build().RunAsync();

This turns your Blazor component into a custom HTML tag.

Step 3: Use in Angular

<!-- app.component.html --><weather-component message="Live data from Blazor!"></weather-component>

Now, the Angular app renders the Blazor component directly.

Advantages

  • Reuse .NET libraries and models in front-end

  • No need to rewrite existing C# code in TypeScript

  • Easier migration path from Angular to Blazor

Limitations

  • Slightly more complex build and deployment

  • Cross-framework communication can add overhead

  • The browser must support WebAssembly

5. Choosing Between WebAssembly and Blazor Interop

ScenarioRecommended Approach
Need raw performance for heavy computationAngular + WebAssembly
Want to reuse C# business logic in UIAngular + Blazor Interop
Already have large Angular app but plan to move to Blazor slowlyBlazor Interop (hybrid)
Working with C++/Rust librariesWebAssembly
Need tighter .NET ecosystem integrationBlazor

6. Real-World Example

A financial analytics company built a large Angular dashboard but needed to run complex interest rate simulations in real-time.
Instead of running those calculations in TypeScript, they:

  • Wrote the logic in C#

  • Compiled it to WebAssembly

  • Integrated it into Angular using a simple service

The result: 60% faster processing, with no major rewrite of the UI.

7. Best Practices

  • Keep communication between Angular and WASM minimal (data marshalling is expensive).

  • Use WebAssembly only for CPU-heavy logic, not simple CRUD.

  • For Blazor interop, define clear boundaries between Angular (UI) and Blazor (.NET logic).

  • Cache .wasm modules for better load times.

  • Always profile performance before and after integration.

8. Conclusion

Both Angular + WebAssembly and Angular + Blazor Interop offer innovative ways to extend what Angular can do.

  • Use Angular + WebAssembly when you need high performance and want to integrate compiled code like C++ or C#.

  • Use Angular + Blazor Interop when you want to share .NET code, logic, or slowly migrate toward a Blazor-based architecture.

By combining the power of Angular’s UI and .NET’s backend strength, you can build fast, modern, and scalable web applications that work seamlessly across browsers.
Membership not found