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ROHIT SINGH
ROHIT SINGH

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Angular Signals vs RxJS — Do We Still Need Observables?

#angular #discuss #typescript

TL;DR: Angular Signals simplify state management and boost performance, while RxJS still rules async workflows. In 2025, the real power comes from using both correctly, not choosing sides.

Why This Topic Is Exploding in 2025 🔥

If you’re an Angular developer, you’ve probably seen these questions everywhere:

  • Are Angular Signals replacing RxJS?
  • Should I stop using Observables?
  • Is Angular moving away from reactive programming?

With Angular 16+ introducing Signals and Angular 19 making them more mature, the ecosystem is clearly shifting. But many developers are confused — and confusion creates massive search demand.

This article will clear that confusion once and for all.

⏱️ Reading time: ~4–5 minutes

What Are Angular Signals? (Simple Explanation)

Angular Signals are a new reactive primitive designed to manage local and global state more easily.

Think of a Signal as:

A variable that automatically tells Angular “Hey, I changed — update the UI.”

Example: Signal in Angular 

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

const count = signal(0);

count.set(1);
count.update(v => v + 1);
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Whenever count changes, Angular automatically updates only the parts of the UI that depend on it.

Key Features of Signals

  • ✅ No subscriptions
  • ✅ No async pipe
  • ✅ Fine-grained change detection
  • ✅ Better performance than Zone.js-based detection

What Is RxJS? (And Why It Still Exists)

RxJS is a reactive programming library built around streams of data over time.

It shines when dealing with:

  • HTTP requests
  • WebSockets
  • User events
  • Real-time data
  • Complex async flows

Example: RxJS Observable 

this.http.get('/api/users')
  .subscribe(users => console.log(users));
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RxJS isn’t just about data — it’s about time, events, and cancellation.

Signals vs RxJS — Core Differences

Feature Angular Signals RxJS
Primary Use State management Async & event streams
Learning Curve Easy Steep
Subscriptions ❌ No ✅ Yes
Memory Leaks Rare Common if misused
Performance Very high Depends on usage
Best For UI state APIs, events, real-time data

The Biggest Myth: “Signals Will Replace RxJS” ❌

This is completely false.

Angular team’s real vision:

Signals for state, RxJS for async logic

They solve different problems.

Trying to replace RxJS with Signals is like trying to replace SQL with variables — wrong tool.

Real-World Use Cases (Very Important 👇)

✅ Use Signals When:

  • Managing component state
  • Handling UI flags (loading, error, toggles)
  • Storing derived values
  • Optimizing performance-critical screens 
isLoading = signal(false);
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✅ Use RxJS When:

  • Calling APIs
  • Handling debouncing/throttling
  • Managing WebSocket connections
  • Working with streams or Kafka-like flows 
this.search$
  .pipe(debounceTime(300), switchMap(q => api(q)))
  .subscribe();
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Using Signals + RxJS Together (Best Practice 2025) ⭐

This is where modern Angular shines.

Pattern: RxJS → Signal 

users = signal<User[]>([]);

ngOnInit() {
  this.http.get<User[]>('/api/users')
    .subscribe(data => this.users.set(data));
}
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RxJS handles async → Signal handles state.

Performance: Signals vs RxJS

Signals introduce fine-grained reactivity:

  • No full component tree checks
  • No Zone.js dependency
  • Only affected UI updates

This makes Angular:

  • ⚡ Faster
  • 🧠 Predictable
  • 🚀 Ready for zoneless future

Should You Migrate Existing Apps?

❌ Don’t Rewrite Everything

Migration strategy:

  1. Keep RxJS for APIs
  2. Introduce Signals for new state
  3. Gradually refactor heavy UI logic

Angular 19 supports coexistence, not replacement.

Common Mistakes Developers Make

❌ Using Signals for HTTP calls
❌ Removing RxJS completely
❌ Creating Signals everywhere
❌ Ignoring cleanup in RxJS

Balance is the key.

The Future of Angular (2025–2027)

What’s coming:

  • Zoneless Angular by default
  • Signals-based reactivity core
  • RxJS as async backbone
  • Smaller bundles & faster hydration

Angular is not dying — it’s evolving.

Final Verdict 🧠

  • Signals → UI & state
  • RxJS → async & streams
  • Together → modern Angular

If you master both, you are future-proof.

If you found this useful ❤️

  • Share it with your Angular team
  • Save it for interviews
  • Follow for more real-world Angular & Node.js content
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