NgRx vs Signal: Key Differences and When to Use Each

NgRx is a powerful state management library using a Redux pattern with actions and reducers, ideal for complex apps. Signals are a new Angular reactive primitive for fine-grained reactivity and simpler state updates without boilerplate.

Quick Comparison

This table summarizes the main differences between NgRx and Angular signals.

Aspect	NgRx	Signals
Type	State management library (Redux pattern)	Reactive primitive built into Angular
Complexity	Higher, with actions, reducers, effects	Lower, simple reactive variables
Boilerplate	More code for setup and updates	Minimal code, direct state mutation
Use case	Large apps with complex state and side effects	Small to medium apps or local component state
Reactivity	Observable-based, uses selectors	Fine-grained, automatic dependency tracking
Learning curve	Steeper due to concepts and patterns	Gentle, easy to adopt

Key Differences

NgRx uses a Redux-inspired pattern with a global store, actions, reducers, and effects to manage state changes predictably. It relies heavily on RxJS observables and selectors to react to state updates, making it suitable for large-scale applications with complex state logic and asynchronous side effects.

In contrast, Angular signals are a new reactive primitive introduced to simplify reactivity by tracking dependencies automatically. Signals allow direct mutation of state with immediate updates to any dependent computations or UI, reducing boilerplate and improving performance for simpler or local state management.

While NgRx enforces immutability and strict unidirectional data flow, signals offer a more flexible and fine-grained approach that fits well with Angular's template system and standalone components. Choosing between them depends on app complexity and developer preference for explicit patterns versus simplicity.

Code Comparison

Here is how you manage a simple counter state increment using NgRx with actions and reducers.

typescript

import { createAction, createReducer, on, Store } from '@ngrx/store';
import { Component } from '@angular/core';

// Action
export const increment = createAction('[Counter] Increment');

// State
export interface CounterState {
  count: number;
}

const initialState: CounterState = { count: 0 };

// Reducer
export const counterReducer = createReducer(
  initialState,
  on(increment, state => ({ count: state.count + 1 }))
);

// Component
@Component({
  selector: 'app-counter',
  template: `
    <button (click)="increment()">Increment</button>
    <div>Count: {{ count$ | async }}</div>
  `
})
export class CounterComponent {
  count$ = this.store.select(state => state.count);

  constructor(private store: Store<{ count: number }>) {}

  increment() {
    this.store.dispatch(increment());
  }
}

Output

A button labeled 'Increment' and a text showing 'Count: 0' initially, increasing by 1 each click.

Signals Equivalent

The same counter using Angular signals is simpler and requires less setup.

typescript

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

@Component({
  selector: 'app-counter',
  template: `
    <button (click)="increment()">Increment</button>
    <div>Count: {{ count() }}</div>
  `
})
export class CounterComponent {
  count = signal(0);

  increment() {
    this.count.update(c => c + 1);
  }
}

Output

A button labeled 'Increment' and a text showing 'Count: 0' initially, increasing by 1 each click.

When to Use Which

Choose NgRx when building large Angular applications that require a predictable, centralized state management system with clear action flows and side effect handling. It is ideal for apps with complex state interactions and asynchronous operations.

Choose Angular signals for simpler or medium-sized apps where you want minimal boilerplate and fine-grained reactivity. Signals work great for local component state or when you want fast, direct updates without the overhead of a full state management library.

In some cases, you can combine both: use NgRx for global state and signals for local reactive state inside components.

Key Takeaways

NgRx is best for complex, large-scale state management with strict patterns.

Angular signals offer simple, fine-grained reactivity with less code.

Use NgRx for predictable global state and side effects.

Use signals for local state and fast UI updates.

You can combine both approaches depending on app needs.