Authentication and Authorization in Next.js

In this section, we will guide you through implementing user authentication and access control in your Next.js application. You'll learn how to achieve secure user logins and effective user permission management using services like Firebase or Auth0.

User Authentication with Firebase

Firebase provides a comprehensive set of tools for building authentication systems. Below is an example of how to set up user authentication using Firebase in your Next.js application:

Set up a Firebase project and enable authentication services.

Install the Firebase JavaScript SDK:

npm install firebase

Configure Firebase in your application:

import firebase from 'firebase/app';
import 'firebase/auth';

const firebaseConfig = {
  apiKey: 'YOUR_API_KEY',
  authDomain: 'YOUR_AUTH_DOMAIN',
  projectId: 'YOUR_PROJECT_ID',
  storageBucket: 'YOUR_STORAGE_BUCKET',
  messagingSenderId: 'YOUR_MESSAGING_SENDER_ID',
  appId: 'YOUR_APP_ID',

if (!firebase.apps.length) {

Implement user authentication:

import firebase from 'firebase/app';
import 'firebase/auth';

// Sign up with email and password
const signUpWithEmail = async (email, password) => {
  try {
    await firebase.auth().createUserWithEmailAndPassword(email, password);
  } catch (error) {

// Sign in with email and password
const signInWithEmail = async (email, password) => {
  try {
    await firebase.auth().signInWithEmailAndPassword(email, password);
  } catch (error) {

User Authentication with Auth0

Auth0 is an authentication and authorization platform that makes it easy to integrate secure user authentication into your application. Here's how you can use Auth0 for user authentication in your Next.js app:

Sign up for an Auth0 account and create an application.

Install the Auth0 SDK:

npm install @auth0/auth0-react

Configure Auth0 in your application:

import { Auth0Provider } from '@auth0/auth0-react';

const Auth0ProviderWithHistory = ({ children }) => {
  const domain = 'YOUR_AUTH0_DOMAIN';
  const clientId = 'YOUR_CLIENT_ID';

  return (

Implement user authentication:

import { useAuth0 } from '@auth0/auth0-react';

function AuthButton() {
  const { isAuthenticated, loginWithRedirect, logout } = useAuth0();

  if (isAuthenticated) {
    return <button onClick={() => logout()}>Log out</button>;
  } else {
    return <button onClick={() => loginWithRedirect()}>Log in</button>;

Access Control and Authorization

In addition to authentication, access control and authorization ensure that users have the appropriate permissions to access certain parts of your application. You can manage user roles and permissions using Firebase or implement custom authorization logic based on user attributes.


This section has shown you how to implement user authentication and access control in your Next.js application using services like Firebase or Auth0. By ensuring secure user logins and controlling user permissions effectively, you can create a safer and more tailored user experience in your application.