State management libraries are essential in modern web development, particularly in React applications, as they help manage the state of an application in a predictable and efficient manner. These libraries provide various approaches to handle state, side effects, and form management, making it easier for developers to build scalable and maintainable applications. Each library has its unique features and design principles, catering to different use cases and developer preferences.
Redux is a predictable state container for JavaScript apps.
It helps you write applications that behave consistently, run in different environments (client, server, and native), and are easy to test. On top of that, it provides a great developer experience, such as live code editing combined with a time traveling debugger.
You can use Redux together with React, or with any other view library. The Redux core is tiny (2kB, including dependencies), and has a rich ecosystem of addons.
Redux Toolkit is our official recommended approach for writing Redux logic. It wraps around the Redux core, and contains packages and functions that we think are essential for building a Redux app. Redux Toolkit builds in our suggested best practices, simplifies most Redux tasks, prevents common mistakes, and makes it easier to write Redux applications.
Installation
Create a React Redux App
The recommended way to start new apps with React and Redux Toolkit is by using our official Redux Toolkit + TS template for Vite, or by creating a new Next.js project using Next's with-redux template.
Both of these already have Redux Toolkit and React-Redux configured appropriately for that build tool, and come with a small example app that demonstrates how to use several of Redux Toolkit's features.
# Vite with our Redux+TS template
# (using the `degit` tool to clone and extract the template)
npx degit reduxjs/redux-templates/packages/vite-template-redux my-app
# Next.js using the `with-redux` template
npx create-next-app --example with-redux my-app
We do not currently have official React Native templates, but recommend these templates for standard React Native and for Expo:
- https://github.com/rahsheen/react-native-template-redux-typescript
- https://github.com/rahsheen/expo-template-redux-typescript
npm install @reduxjs/toolkit react-redux
For the Redux core library by itself:
npm install redux
For more details, see the Installation docs page.
Documentation
The Redux core docs are located at https://redux.js.org, and include the full Redux tutorials, as well usage guides on general Redux patterns:
The Redux Toolkit docs are available at https://redux-toolkit.js.org, including API references and usage guides for all of the APIs included in Redux Toolkit.
Learn Redux
Redux Essentials Tutorial
The Redux Essentials tutorial is a "top-down" tutorial that teaches "how to use Redux the right way", using our latest recommended APIs and best practices. We recommend starting there.
Redux Fundamentals Tutorial
The Redux Fundamentals tutorial is a "bottom-up" tutorial that teaches "how Redux works" from first principles and without any abstractions, and why standard Redux usage patterns exist.
Help and Discussion
The #redux channel of the Reactiflux Discord community is our official resource for all questions related to learning and using Redux. Reactiflux is a great place to hang out, ask questions, and learn - please come and join us there!
Before Proceeding Further
Redux is a valuable tool for organizing your state, but you should also consider whether it's appropriate for your situation. Please don't use Redux just because someone said you should - instead, please take some time to understand the potential benefits and tradeoffs of using it.
Here are some suggestions on when it makes sense to use Redux:
- You have reasonable amounts of data changing over time
- You need a single source of truth for your state
- You find that keeping all your state in a top-level component is no longer sufficient
Yes, these guidelines are subjective and vague, but this is for a good reason. The point at which you should integrate Redux into your application is different for every user and different for every application.
For more thoughts on how Redux is meant to be used, please see:
Basic Example
The whole global state of your app is stored in an object tree inside a single store. The only way to change the state tree is to create an action, an object describing what happened, and dispatch it to the store. To specify how state gets updated in response to an action, you write pure reducer functions that calculate a new state based on the old state and the action.
Redux Toolkit simplifies the process of writing Redux logic and setting up the store. With Redux Toolkit, the basic app logic looks like:
import { createSlice, configureStore } from '@reduxjs/toolkit'
const counterSlice = createSlice({
name: 'counter',
initialState: {
value: 0
},
reducers: {
incremented: state => {
// Redux Toolkit allows us to write "mutating" logic in reducers. It
// doesn't actually mutate the state because it uses the Immer library,
// which detects changes to a "draft state" and produces a brand new
// immutable state based off those changes
state.value += 1
},
decremented: state => {
state.value -= 1
}
}
})
export const { incremented, decremented } = counterSlice.actions
const store = configureStore({
reducer: counterSlice.reducer
})
// Can still subscribe to the store
store.subscribe(() => console.log(store.getState()))
// Still pass action objects to `dispatch`, but they're created for us
store.dispatch(incremented())
// {value: 1}
store.dispatch(incremented())
// {value: 2}
store.dispatch(decremented())
// {value: 1}
Redux Toolkit allows us to write shorter logic that's easier to read, while still following the original core Redux behavior and data flow.
Logo
You can find the official logo on GitHub.
Change Log
This project adheres to Semantic Versioning. Every release, along with the migration instructions, is documented on the GitHub Releases page.