Server-Sent Events in .NET 10: Do You Really Need SignalR?

Real-time updates have become a default expectation in modern web applications. Dashboards refresh automatically, notifications arrive instantly, and long-running operations stream progress back to the UI. In the .NET ecosystem, SignalR has traditionally been the go-to solution for these scenarios.

However, with .NET 10, Server-Sent Events (SSE) have become a first‑class, production-ready option that deserves serious consideration. In many cases, SignalR may actually be overkill.

This post explores:

• What Server-Sent Events are

• How SSE works in .NET 10

• The benefits of SSE over SignalR

• When SignalR is the right choice

• How to decide which approach fits your application

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What Are Server-Sent Events (SSE)?

Server-Sent Events provide a simple, standards-based way for a server to push data to a browser or client over HTTP.

Key characteristics:

• One-way communication (server → client)

• Built on plain HTTP

• Uses the text/event-stream content type

• Automatically reconnects if the connection drops

Unlike WebSockets, SSE does not require a protocol upgrade. It works over normal HTTP connections and is supported natively by modern browsers.

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SSE in .NET 10

.NET 10 significantly improves the developer experience for streaming responses, making SSE straightforward and efficient.

A minimal SSE endpoint looks like this:

app.MapGet("/events", async (HttpContext context) =>

{

context.Response.Headers.Add("Content-Type", "text/event-stream");

for (var i = 0; i < 10; i++)

{

await context.Response.WriteAsync($"data: Update {i}\n\n");

await context.Response.Body.FlushAsync();

await Task.Delay(1000);

}

});

On the client side (browser):

const source = new EventSource("/events");

source.onmessage = e => console.log(e.data);

That’s it—no hubs, no negotiation, no extra libraries.

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Benefits of SSE Over SignalR

1. Simplicity

SSE is dramatically simpler than SignalR:

• No hubs

• No connection negotiation

• No transport fallbacks

• No client libraries required in browsers

For use cases like live dashboards, status updates, or streaming progress, this simplicity reduces both development and maintenance cost.

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2. Native HTTP and Infrastructure Friendly

Because SSE runs over standard HTTP:

• Works seamlessly with reverse proxies (YARP, NGINX, Azure Front Door)

• Plays nicely with Kubernetes ingress

• Easier to observe, debug, and trace

• No sticky sessions required

SignalR often requires additional configuration for scale-out scenarios, especially when WebSockets are involved.

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3. Lower Server Overhead

SignalR provides a lot of functionality:

• Bi-directional messaging

• Group management

• Connection state tracking

• Automatic transport selection

If you don’t need these features, you’re paying for them anyway.

SSE:

• Keeps minimal per-connection state

• Avoids hub abstractions

• Scales well for read-heavy, broadcast-style workloads

This makes SSE ideal for high-fanout scenarios such as analytics dashboards or monitoring screens.

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4. Built-in Reconnection Semantics

SSE automatically reconnects when a connection drops and supports Last-Event-ID out of the box.

This is particularly useful for:

• Unreliable networks

• Mobile clients

• Long-running streams

SignalR can do this too, but again, with more complexity.

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5. Perfect Fit for Event-Driven Backends

If your backend already produces events (Kafka, Redis Streams, Azure Service Bus, outbox patterns), SSE maps naturally to this model.

You can:

• Stream domain events directly to clients

• Avoid translating events into SignalR-specific abstractions

• Keep your API surface HTTP-first

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Is SignalR Overkill?

Sometimes, yes.

SignalR shines when you need:

• Bi-directional communication

• Client-to-server messaging at high frequency

• Group or user-specific routing

• Rich client SDKs across many platforms

But many applications don’t actually need those capabilities.

If your requirements are primarily:

• Server → client updates

• Read-only or command-based writes via normal APIs

• Streaming data or notifications

Then SignalR may be adding unnecessary complexity.

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When SignalR Is the Right Tool

You should still reach for SignalR when:

• Building chat applications

• Collaborative editing tools

• Multiplayer or highly interactive experiences

• Scenarios requiring low-latency two-way messaging

In these cases, SSE simply isn’t designed to compete.

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A Practical Rule of Thumb

Ask yourself one question:

Do my clients really need to talk back in real time?

If the answer is no, start with Server-Sent Events.

You can always introduce SignalR later, but removing it once embedded in your architecture is far harder.

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Final Thoughts

.NET 10 makes Server-Sent Events a compelling, modern choice for real-time updates. They align perfectly with HTTP-first architectures, cloud-native infrastructure, and event-driven systems.

SignalR remains a powerful tool but power comes with cost.

For many applications, SSE is not a compromise it’s the correct solution.

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If you’re building dashboards, forecasting platforms, monitoring tools, or event-driven SaaS systems, SSE should be your default starting point in .NET 10.