Redux / NgRx State Management in Angular

Bhargav Patel — Thu, 07 May 2026 23:38:36 +0000

Managing state in Angular applications becomes difficult as applications grow larger and more complex. Redux and NgRx provide a structured and predictable way to handle shared application state.

This article explains:

What Redux/NgRx solves
Core concepts
When to avoid it
When it becomes useful
Why established libraries are preferred

Understanding State in Angular

State in Angular applications can be anything like:

Router state
Component-local state
Shared state between components

In small applications, services are often enough for sharing data. However, as applications scale, several problems begin to appear:

Complex component relationships
Difficult state synchronization
Duplicate state across components
Unpredictable updates

Redux-style architecture solves this problem by introducing a centralized global store.

The store becomes the single source of truth for application state.

Core Redux / NgRx Concepts

Redux/NgRx is built around a few important concepts:

Store
Actions
Reducers
Effects
Selectors

Store

The store contains the entire application state in one centralized location.

Benefits of using a store:

Single source of truth
Predictable data flow
Easier debugging
Better state sharing

Components subscribe only to the state they need instead of maintaining separate copies.

Actions

Actions describe events that happen inside the application.

Actions are plain JavaScript objects that usually contain:

type
optional payload data

Example:

{
  type: 'LOAD_USERS',
  payload: users
}

Actions help create a clear and trackable update flow.

Reducers

Reducers are functions that receive:

Current state
Action

Reducers return a new updated state.

Important rules for reducers:

Must be pure functions
Must not contain side effects
Should not perform:
- API calls
- Local storage operations
- Async tasks

Reducers should only focus on transforming state.

Effects (NgRx)

Reducers should only update state and remain pure functions. They should not perform API calls, async operations, or side effects.

NgRx uses Effects to handle side effects separately.

Common use cases for effects:

API requests
Authentication
Local storage updates
Async operations
Notifications

Effects help keep components clean and business logic centralized.

Selectors

Selectors are functions used to read data from the store.

Instead of directly accessing store data inside components, selectors provide a reusable and organized way to retrieve state.

Benefits of Selectors:

Cleaner components
Reusable queries
Better maintainability
Derived/computed state
Improved performance through memoization

Selectors make store access predictable, reusable, and easier to maintain in large applications.

Example Flow of Redux / NgRx

Understanding Redux/NgRx becomes easier by following a simple flow.

Example scenario:
A user opens a page and clicks Load Users.

Step 1 — Component Dispatches Action

The component does not directly call the API.

Instead, it dispatches an action.

this.store.dispatch(loadUsers());

Action:

export const loadUsers = createAction('[Users] Load Users');

Purpose:

Describe what happened
Start the state update process

Step 2 — Effect Handles API Call

The effect listens for the dispatched action.

loadUsers$ = createEffect(() =>
  this.actions$.pipe(
    ofType(loadUsers),
    switchMap(() =>
      this.userService.getUsers().pipe(
        map(users => loadUsersSuccess({ users }))
      )
    )
  )
);

Purpose:

Perform async operations
Call APIs
Keep reducers pure

Step 3 — Success Action Is Dispatched

After data is received from the API, another action is dispatched.

export const loadUsersSuccess = createAction(
  '[Users] Load Users Success',
  props<{ users: User[] }>()
);

Purpose:

Notify application that data was loaded successfully

Step 4 — Reducer Updates Store

Reducer receives:

Current state
Action

Then returns updated state.

on(loadUsersSuccess, (state, { users }) => ({
  ...state,
  users
}))

Purpose:

Update application state
Keep state immutable and predictable

Step 5 — Selector Reads Data

Selectors provide clean access to store data.

export const selectUsers = createSelector(
  selectUserState,
  state => state.users
);

Purpose:

Read state
Reuse state queries
Keep components clean

Step 6 — Component Receives Updated Data

Component subscribes to selector data.

users$ = this.store.select(selectUsers);

Purpose:

Automatically receive updated state
Keep UI reactive

Complete Redux / NgRx Flow

Component
   ↓
Dispatch Action
   ↓
Effect Handles API Call
   ↓
Success Action
   ↓
Reducer Updates Store
   ↓
Selector Reads State
   ↓
Component Updates UI

This predictable flow is one of the biggest advantages of Redux/NgRx in large Angular applications.

When NOT to Use Redux / NgRx

Redux/NgRx is not always the right solution.

In many projects, it can introduce unnecessary complexity and slow development.

1. Small Projects or Prototypes

Avoid Redux/NgRx when:

Applications are small
Requirements change frequently
Features are experimental

Reasons:

Too much boilerplate
Slower development
Architecture overhead is unnecessary

2. Shared UI or Component Libraries

Avoid embedding Redux inside reusable component libraries.

Reasons:

Forces every consuming project to use Redux
Different projects may not require global state management
Reduces flexibility

3. Teams Without Redux Experience

Avoid Redux/NgRx in important projects if the team lacks experience.

Possible issues:

Difficult debugging
Poor architecture decisions
Hard-to-maintain code
Incorrect implementation patterns

State management libraries require strong architectural understanding.

4. Applications Already Using Apollo Client

Apollo Client already provides state management for GraphQL applications.

Using Redux together with Apollo may create:

Multiple sources of truth
Synchronization issues
Extra complexity

In many GraphQL applications, Apollo alone is enough.

Common Drawbacks of Redux / NgRx

Even small features may require:

Actions
Reducers
Effects
Selectors
Store updates

This increases:

Boilerplate
Development time
Learning curve

For simple applications, this overhead may not be worth it.

When Redux / NgRx Makes Sense

Redux/NgRx becomes valuable in large and state-heavy applications.

1. Large Applications

Good fit for applications with:

Hundreds of components
Deep component trees
Complex shared state

Benefits:

Centralized architecture
Predictable updates
Easier debugging
Better maintainability

2. Undo / Redo Functionality

Redux works well for applications requiring:

Undo functionality
Redo functionality
Reverting changes
Optimistic UI updates

Reason:

State history can be tracked and restored easily

3. State Persistence

Redux is useful when applications need to:

Save application state
Restore sessions
Synchronize state across clients
Store state in local storage

Redux naturally supports state serialization.

4. Large Legacy System Migrations

Redux can help when:

Migrating large systems
Scaling existing applications
Replacing fragile custom state patterns

Using a structured architecture early helps reduce long-term complexity.

Signs That Redux May Be Needed

Redux/NgRx becomes worth considering when:

Multiple services start coordinating state manually
State synchronization becomes difficult
Custom state patterns begin appearing
Debugging shared data becomes painful

These are common indicators that application complexity is increasing.

Why Established Libraries Are Better

Using mature libraries like Redux/NgRx provides:

Community support
Better documentation
Standardized architecture
Easier onboarding
Long-term maintainability

Custom in-house state solutions often become:

Poorly documented
Difficult to scale
Hard for new developers to understand

Established libraries reduce long-term architectural risk.

Final Thoughts

Redux/NgRx should be treated as an architectural decision rather than a default choice.

Avoid Redux/NgRx When

Applications are small
Rapid development is important
Requirements change frequently
Apollo Client already manages state

Consider Redux/NgRx When

Applications are large and complex
Shared state becomes difficult to manage
Predictability is important
Undo/restore features are required
Long-term scalability matters

The additional complexity of Redux/NgRx is justified only when application scale and state management needs become significant.

DEV Community: Bhargav Patel

Redux / NgRx State Management in Angular

Understanding State in Angular

Core Redux / NgRx Concepts

Store

Actions

Reducers

Effects (NgRx)

Selectors

Example Flow of Redux / NgRx

Step 1 — Component Dispatches Action

Step 2 — Effect Handles API Call

Step 3 — Success Action Is Dispatched

Step 4 — Reducer Updates Store

Step 5 — Selector Reads Data

Step 6 — Component Receives Updated Data

Complete Redux / NgRx Flow

When NOT to Use Redux / NgRx

1. Small Projects or Prototypes

2. Shared UI or Component Libraries

3. Teams Without Redux Experience

4. Applications Already Using Apollo Client

Common Drawbacks of Redux / NgRx

When Redux / NgRx Makes Sense

1. Large Applications

2. Undo / Redo Functionality

3. State Persistence

4. Large Legacy System Migrations

Signs That Redux May Be Needed

Why Established Libraries Are Better

Final Thoughts

Avoid Redux/NgRx When

Consider Redux/NgRx When