Angular Signals vs RxJS: Which Should You Use in 2025?

Since the introduction of Angular Signals, the Angular ecosystem has been evolving rapidly toward a simpler, more intuitive way to handle reactivity. Meanwhile, RxJS has been the go-to for reactive programming in Angular for years.

So, what’s the difference? When should you use Signals, and when is RxJS still the better choice?

Let’s break it down 👇

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🧠 What Are Angular Signals?

Signals are a new reactive primitive introduced in Angular. They're designed to track dependencies automatically and re-render components efficiently when values change.

import { signal } from '@angular/core';

const count = signal(0);

function increment() {
  count.set(count() + 1);
}

Unlike RxJS, Signals are pull-based and synchronous. That means changes propagate automatically, and you don’t have to manually subscribe/unsubscribe.

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🔁 What Is RxJS?

RxJS (Reactive Extensions for JavaScript) is a powerful library for working with streams of data. It's push-based, async by design, and perfect for complex data flows like HTTP requests, WebSockets, and time-based operations.

import { BehaviorSubject } from 'rxjs';

const count$ = new BehaviorSubject(0);

function increment() {
  count$.next(count$.value + 1);
}

With RxJS, you get access to a rich set of operators like map, filter, mergeMap, etc.

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✅ Signals: Pros & Cons

✅ Pros

• Simplicity: Easy to use, especially for local state.
• Automatic tracking: No manual subscriptions.
• Great for UI bindings: Perfect in templates and components.
• Sync updates: No async zone issues.

❌ Cons

• Not suitable for streams: Can't handle time-based or event-based data well.
• Limited operators: Lacks the powerful stream operators RxJS provides.

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✅ RxJS: Pros & Cons

✅ Pros

• Powerful: Perfect for complex data flows.
• Mature ecosystem: Tons of operators and support.
• Async-first: Great for HTTP, intervals, and async sources.

❌ Cons

• Steep learning curve: Can be overkill for simple state.
• Manual cleanup: Subscriptions need to be managed.
• Less intuitive for beginners.

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🤔 When to Use Signals

Use Angular Signals when:

• Managing component-local state
• Updating UI from synchronous events
• Building simple, reactive forms
• You want better performance with fine-grained reactivity

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🔄 When to Use RxJS

Use RxJS when:

• Working with async data (e.g. HTTP, WebSockets)
• Needing debouncing, throttling, or merging
• Handling complex streams or event sources
• Building highly reactive services

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🔥 Can You Use Both?

Yes — and you should!

Angular doesn't force you to choose one or the other. In fact, using RxJS for async flows and Signals for reactive UI state is often the best of both worlds.

import { Component, OnInit, computed, signal } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { toSignal } from '@angular/core/rxjs-interop';
import { Observable } from 'rxjs';

@Component({
  selector: 'app-user',
  template: `
    <h1>{{ userSignal()?.name }}</h1>
  `
})
export class MyComponent implements OnInit {
  private user$: Observable<User> = this.http.get<User>('/api/user');
  userSignal = toSignal(this.user$);

  constructor(private http: HttpClient) {}
}

The toSignal() utility helps bridge RxJS Observables to Signals.

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🧪 Performance Comparison

Feature	Signals	RxJS
State reactivity	✅ Blazing fast	⚠️ Needs async pipe
Async data handling	❌ Limited	✅ Best in class
Learning curve	✅ Beginner-friendly	❌ Steep
Template integration	✅ Seamless	✅ With async pipe

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🧠 Final Thoughts

• If you're building UI-heavy apps with mostly synchronous state, Signals will drastically simplify your code.
• If you're building apps with data streams, async calls, or complex pipelines, stick to RxJS.
• The best apps in 2025 will likely use both, where each shines.

💬 What are you using in your Angular projects? Let me know in the comments 👇

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#angular #rxjs #signals #webdev #frontend