Real-Time Web Applications using SignalR

 Request-and-response communication is no longer the only communication method used by contemporary web apps. These days, users anticipate real-time dashboards, chat capabilities, live notifications, and quick changes. An ASP.NET Core package called SignalR makes it easier to incorporate real-time capabilities into online apps.

Without requiring clients to query the server frequently, SignalR allows server-side code to instantaneously push content to connected clients. It automatically selects the optimal transport by abstracting sophisticated real-time communication strategies like WebSockets, Server-Sent Events, and Long Polling.

The client submits a request and awaits a response in conventional web apps. The client must resubmit the request if the server's data changes. By enabling the server to proactively broadcast updates to all connected clients or to individual users, SignalR reverses this flow.

Live chat apps, stock price updates, live dashboards, notification systems, multiplayer games, and teamwork tools are a few examples of real-time use cases.

The Hub is the central component of SignalR. A hub is a high-level pipeline that enables method calls between the client and server.

Creating a SignalR Hub

using Microsoft.AspNetCore.SignalR;

public class NotificationHub : Hub
{
    public async Task SendMessage(string user, string message)
    {
        await Clients.All.SendAsync("ReceiveMessage", user, message);
    }
}

C#

This hub exposes a method, SendMessage, that clients can call. The server then broadcasts the message to all connected clients using Clients.All.

Registering SignalR in Program.cs

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddSignalR();

var app = builder.Build();

app.MapHub<NotificationHub>("/notificationHub");

app.Run();

C#

Here, SignalR services are registered and the hub is mapped to a specific endpoint. Clients will connect to /notificationHub.

Client-Side JavaScript Integration

<script src="https://cdnjs.cloudflare.com/ajax/libs/microsoft-signalr/7.0.5/signalr.min.js"></script>

<script>
    const connection = new signalR.HubConnectionBuilder()
        .withUrl("/notificationHub")
        .build();

    connection.on("ReceiveMessage", function (user, message) {
        const msg = user + ": " + message;
        document.getElementById("messages").innerHTML += "<li>" + msg + "</li>";
    });

    connection.start();

    function sendMessage() {
        const user = document.getElementById("user").value;
        const message = document.getElementById("message").value;
        connection.invoke("SendMessage", user, message);
    }
</script>

HTML

This client code establishes a real-time connection with the SignalR hub. When the server sends a message using ReceiveMessage, the client immediately updates the UI without refreshing the page.

HTML UI Example

<input id="user" placeholder="User name" />
<input id="message" placeholder="Message" />
<button onclick="sendMessage()">Send</button>

<ul id="messages"></ul>

HTML

Once connected, multiple users can open the page and see messages appear instantly when someone sends a message.

SignalR supports multiple communication patterns. Broadcasting sends messages to all connected clients, while targeted messaging can send data to specific users, groups, or connections. Group messaging is especially useful for chat rooms, notifications by role, or department-based updates.

Another powerful feature of SignalR is automatic reconnection. If the connection drops due to network issues, SignalR can reconnect clients seamlessly, improving reliability.

SignalR also integrates well with authentication and authorization. You can restrict hub access using policies or roles, making it secure for enterprise applications.

Creating a SignalR Hub

using Microsoft.AspNetCore.SignalR;

public class NotificationHub : Hub
{
    public async Task SendMessage(string user, string message)
    {
        await Clients.All.SendAsync("ReceiveMessage", user, message);
    }
}

C#

This hub exposes a method, SendMessage, that clients can call. The server then broadcasts the message to all connected clients using Clients.All.

Registering SignalR in Program.cs

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddSignalR();

var app = builder.Build();

app.MapHub<NotificationHub>("/notificationHub");

app.Run();

C#

Here, SignalR services are registered and the hub is mapped to a specific endpoint. Clients will connect to /notificationHub.

Client-Side JavaScript Integration

<script src="https://cdnjs.cloudflare.com/ajax/libs/microsoft-signalr/7.0.5/signalr.min.js"></script>

<script>
    const connection = new signalR.HubConnectionBuilder()
        .withUrl("/notificationHub")
        .build();

    connection.on("ReceiveMessage", function (user, message) {
        const msg = user + ": " + message;
        document.getElementById("messages").innerHTML += "<li>" + msg + "</li>";
    });

    connection.start();

    function sendMessage() {
        const user = document.getElementById("user").value;
        const message = document.getElementById("message").value;
        connection.invoke("SendMessage", user, message);
    }
</script>

HTML

This client code establishes a real-time connection with the SignalR hub. When the server sends a message using ReceiveMessage, the client immediately updates the UI without refreshing the page.

HTML UI Example

<input id="user" placeholder="User name" />
<input id="message" placeholder="Message" />
<button onclick="sendMessage()">Send</button>

<ul id="messages"></ul>

HTML

Once connected, multiple users can open the page and see messages appear instantly when someone sends a message.

SignalR supports multiple communication patterns. Broadcasting sends messages to all connected clients, while targeted messaging can send data to specific users, groups, or connections. Group messaging is especially useful for chat rooms, notifications by role, or department-based updates.

Another powerful feature of SignalR is automatic reconnection. If the connection drops due to network issues, SignalR can reconnect clients seamlessly, improving reliability.

SignalR also integrates well with authentication and authorization. You can restrict hub access using policies or roles, making it secure for enterprise applications.

In terms of performance, SignalR scales efficiently when combined with backplanes like Redis or Azure SignalR Service, allowing thousands of concurrent connections across multiple servers.

When to use SignalR

• Live chat systems

• Real-time notifications

• Stock market or crypto price updates

• Live dashboards and monitoring systems

• Collaborative applications

In conclusion, SignalR dramatically simplifies real-time web development in ASP.NET Core. By abstracting low-level communication details, it allows developers to focus on business logic while delivering fast, interactive, and modern user experiences.

In terms of performance, SignalR scales efficiently when combined with backplanes like Redis or Azure SignalR Service, allowing thousands of concurrent connections across multiple servers.

When to use SignalR

• Live chat systems

• Real-time notifications

• Stock market or crypto price updates

• Live dashboards and monitoring systems

• Collaborative applications

In conclusion, SignalR dramatically simplifies real-time web development in ASP.NET Core. By abstracting low-level communication details, it allows developers to focus on business logic while delivering fast, interactive, and modern user experiences.

SignalR Hosting Recommendation

One of the most important things when choosing a good SignalR Hosting is the feature and reliability. HostForLIFE is the leading provider of Windows hosting and affordable SignalR Hosting, their servers are optimized for PHP web applications. The performance and the uptime of the hosting service are excellent and the features of the web hosting plan are even greater than what many hosting providers ask you to pay for. 

At HostForLIFE.eu, customers can also experience fast SignalR hosting. The company invested a lot of money to ensure the best and fastest performance of the datacenters, servers, network and other facilities. Its datacenters are equipped with the top equipments like cooling system, fire detection, high speed Internet connection, and so on. That is why HostForLIFE guarantees 99.9% uptime for SignalR Hosting. And the engineers do regular maintenance and monitoring works to assure its SignalR hosting are security and always up.