How to choose the right Blazor hosting model

Choosing the right Blazor hosting model depends on your application's requirements, infrastructure, and use case. Blazor offers two main hosting models:

1. Blazor Server

2. Blazor WebAssembly (WASM)

Blazor Server

In the Blazor Server model, the application runs on the server, and the UI is updated over a real-time SignalR connection.

Pros:

✅ Faster initial load: The app loads almost instantly because no WebAssembly files are downloaded.

✅ Smaller client size: The browser only downloads a lightweight JavaScript library for SignalR.

✅ Access to server resources: You can directly call server-side code and use server-side APIs.

✅ Full .NET support: No limitations due to browser sandboxing (e.g., file handling, database access).

✅ Reduced client requirements: Works even on low-spec devices since all processing happens on the server.

Cons:

• ❌ Latency: Requires constant communication between the client and server, which can lead to delays in a slow network.

• ❌ Scalability challenges: Each connected user consumes server resources for the SignalR connection.

• ❌ Offline support: Cannot work offline; the app stops functioning if the connection is lost.

Use Cases:

• Apps with real-time requirements (e.g., dashboards, collaborative tools).

• Intranet or enterprise apps where network reliability is high.

• Applications that require server-side security for sensitive data.

Blazor WebAssembly (WASM)

In the Blazor WebAssembly model, the app runs entirely on the browser using WebAssembly. The application and .NET runtime are downloaded to the client.

Pros:

• ✅ Offline support: Once downloaded, the app can run without a server connection.

• ✅ Reduced server load: Processing happens on the client-side, so the server only handles API requests.

• ✅ Better scalability: Since server resources are not tied to user sessions, it's easier to scale.

• ✅ Portable: Runs on any modern browser without dependencies.

• ✅ Static hosting: Can be hosted on a CDN or static file host (e.g., GitHub Pages, Azure Static Web Apps).

Cons:

• ❌ Large initial download: The .NET runtime and app files need to be downloaded, which increases load time.

• ❌ Limited browser API access: Some server-side capabilities are restricted due to browser sandboxing.

• ❌ Dependency on client performance: Demands more resources from the user's device.

Use Cases:

• Public-facing apps with many users.

• Progressive Web Apps (PWAs) requiring offline functionality.

• Scalable applications with static hosting.

Hybrid: Blazor Server + WebAssembly

In some cases, you can combine the two models. For example:

• Use Blazor Server for complex, real-time pages (e.g., admin dashboards).

• Use Blazor WebAssembly for lightweight, client-focused features.

Factors to Consider

• Initial Load Time

  • If quick load time is critical, go for Blazor Server.

  • If users are okay with a larger initial download, use Blazor WebAssembly.

• Network Dependency

  • Need offline support? Use Blazor WebAssembly.

  • Stable network available? Use Blazor Server.

• Scalability

  • Many users? Use Blazor WebAssembly to reduce server load.

  • Controlled user base? Use Blazor Server.

• Server Resources

  • Limited server resources? Use Blazor WebAssembly.

  • High server capacity? Use Blazor Server.

• Security

  • Sensitive business logic or data processing? Use Blazor Server to keep logic server-side.

  • Minimal sensitive data? Use Blazor WebAssembly.

Comparison Table