Simplifying Authentication: A Comprehensive Guide to Implementing Auth0 with React and Next.js

As web applications become more complex, user authentication and access control become critical components. However, building a scalable, secure, and easy-to-use authentication system can be a daunting task. Fortunately, Auth0 provides a powerful and flexible identity management platform that makes implementing authentication solutions a breeze. In this tutorial, we will explore how to integrate Auth0 with React and Next.js to simplify and streamline your application's authentication process.

What is Auth0?

Auth0 is a cloud-based identity management platform that provides authentication and authorization solutions for web, mobile, and legacy applications. With Auth0, you can easily add social and enterprise identity providers, such as Google, Facebook, and Microsoft, to your application without having to deal with the complexities of each individual integration.

Getting Started with Auth0

Before we dive into integrating Auth0 with our React and Next.js application, we need to set up an Auth0 account and create a new application.

  1. Navigate to the Auth0 website and create an account if you don't already have one.
  2. Create a new application by clicking on the "Applications" tab in the dashboard and selecting "Create Application".
  3. Choose "Single Page Web Applications" as the application type.
  4. Provide a name for your application, and make sure the "Development" environment is selected.
  5. Under the "Settings" tab, configure the following fields:
    • Allowed Callback URLs: set this to "http://localhost:3000/callback" (assuming you are running your application locally on port 3000). This URL will be used by Auth0 to redirect the user after authentication.
    • Allowed Logout URLs: set this to "http://localhost:3000" (assuming you are running your application locally on port 3000). This URL will be used by Auth0 to redirect the user after logging out.
  6. Save your changes to the application settings.

Integrating Auth0 with React and Next.js

Now that we have our Auth0 account and application set up, let's integrate it with our React and Next.js application.

First, we need to install the necessary Auth0 packages:

    npm install --save auth0-js react-auth0-wrapper

Next, we need to create a configuration file for our Auth0 setup. Create a new file called `auth0.js` in your project's root directory and add the following code:

    import auth0 from 'auth0-js';

    class Auth0 {
      constructor() {
        this.auth0 = new auth0.WebAuth({
          domain: '',
          clientID: '',
          redirectUri: 'http://localhost:3000/callback',
          responseType: 'token id_token',
          scope: 'openid profile email'

      login = () => {

      handleAuthentication = () => {
        return new Promise((resolve, reject) => {
          this.auth0.parseHash((err, authResult) => {
            if (authResult && authResult.accessToken && authResult.idToken) {
            } else if (err) {

      setSession = (authResult) => {
        // Set the time that the access token will expire at
        let expiresAt = JSON.stringify(
          authResult.expiresIn * 1000 + new Date().getTime()

        localStorage.setItem('access_token', authResult.accessToken);
        localStorage.setItem('id_token', authResult.idToken);
        localStorage.setItem('expires_at', expiresAt);

      isAuthenticated = () => {
        let expiresAt = JSON.parse(localStorage.getItem('expires_at'));
        return new Date().getTime() < expiresAt;

      logout = () => {
          returnTo: window.location.origin

    const auth0Client = new Auth0();

    export default auth0Client;

Make sure to replace `` and `` with the corresponding values from your Auth0 application settings.

This code sets up an `Auth0` class with methods for logging in, handling authentication, checking authentication status, and logging out. It also uses `localStorage` to store the user's access and ID tokens.

Next, we need to create a higher-order component (HOC) that will wrap our application and provide access to the `Auth0` methods. Create a new file called `withAuth.js` in your project's root directory and add the following code:

    import React, { useState, useEffect, useContext } from 'react';
    import auth0Client from './auth0';

    const AuthContext = React.createContext(null);

    export const useAuth = () => useContext(AuthContext);

    function AuthProvider({ children }) {
      const [isAuthenticated, setIsAuthenticated] = useState(false);
      const [user, setUser] = useState(null);
      const [authLoading, setAuthLoading] = useState(true);

      useEffect(() => {
        const initializeAuth = async () => {
          try {
            if ('code=')) {
              await auth0Client.handleAuthentication();


            if (isAuthenticated) {
          } catch (error) {
          } finally {

      }, [isAuthenticated]);

      const login = () => auth0Client.login();
      const logout = () => auth0Client.logout();

      const contextValue = {

      if (authLoading) {

Loading authentication...

; } return ( {children} ); } export default AuthProvider;

The `AuthProvider` component uses React's `useEffect` hook to initialize the authentication state. It also provides a `useAuth` hook for accessing the authentication methods and state from within child components. The `authLoading` state is used to display a loading message while the authentication state is being initialized.

Now that we have our Auth0 setup and authentication provider in place, we can start using it in our application. In your `pages/_app.js` file, wrap your application with the `AuthProvider` component:

    import AuthProvider from '../components/AuthProvider';

    function MyApp({ Component, pageProps }) {
      return (
          <Component {...pageProps} />

    export default MyApp;

Now, any component in your application can access the authentication state and methods using the `useAuth` hook:

    import { useAuth } from '../components/AuthProvider';

    function Profile() {  
      const { isAuthenticated, user, login, logout } = useAuth();

      if (!isAuthenticated) {

Please login to view your profile.

; } return ( <div> <h1>Welcome, {user.nickname}! <button onClick={() => logout()}>Logout </div> ); }

Security Best Practices

When implementing user authentication, it is essential to follow security best practices to protect your application and user data. Here are some tips to keep in mind:

  1. Use HTTPS: All traffic between your application and the Auth0 servers should be encrypted using HTTPS. Make sure to use SSL certificates issued by trusted certificate authorities.
  2. Validate input: Always validate user input to prevent attacks such as SQL injection and cross-site scripting (XSS).
  3. Encode output: Encode any data sent to the user to prevent XSS attacks.
  4. Limit access privileges: Limit user access to only the necessary parts of your application. Use roles and permissions to control access to resources and actions.
  5. Use two-factor authentication: Enable two-factor authentication (2FA) to add an extra layer of security to your application.
  6. Store user data securely: Passwords should be hashed and salted before storing them in your database.


Auth0 provides an easy and secure way to implement user authentication in your React and Next.js applications. By following the steps outlined in this tutorial, you can quickly set up an Auth0 account and integrate it with your application. Remember to follow security best practices when implementing authentication and access control, and always keep user data safe.