Google Authentication

Google Authentication

  • In this tutorial, we will code google authentication using ExpressJs and passport.js
  • Passport. js is a popular Express middleware specifically created to facilitate the login process. It is flexible, trusted by many organizations worldwide, and easy to integrate into your ExpressJS code.
  • Install passport in the project by the following command:
npm install passport passport-local

To start, Firstly register on your google development site and begin with the following steps:

  • Go to the Google platform: Google platform.
  • Create a new Project and call it whatever you want to. 

  • After creating a new project, let's move to create credentials. Click on CREATE CREDENTIALS, then select OAuth client ID, and then select External.

  • Fill in the information to create credentials and then click on save and continue.

  • Now click on credential on the left-hand side and again Click on CREATE CREDENTIALS, then select OAuth client ID. Select an Application type from the options.

  • Lastly, fill out the form accordingly and click on create.


  • Finally, you get your client ID and client Secret.

  • Now, Let's move to the code part. Firstly, create nodejs project:
npm init -y
  • Install required modules
npm install express passport passport-google-oauth2 cookie-session
  • Here is an application file structure

  • In passport.js
const passport = require('passport');
const GoogleStrategy = require('passport-google-oauth2').Strategy;

passport.serializeUser((user , done) => {
	done(null , user);
passport.deserializeUser(function(user, done) {
	done(null, user);

passport.use(new GoogleStrategy({
	clientID:"YOUR_CLIENTID", // Your Credentials here.
	clientSecret:"YOUR_CLIENT_SECRET", // Your Credentials here.
function(request, accessToken, refreshToken, profile, done) {
	return done(null, profile);

In index.js

const express = require('express');
const app = express();
const passport = require('passport');
const cookieSession = require('cookie-session');

	name: 'google-auth-session',
	keys: ['key1', 'key2']

app.get('/', (req, res) => {
	res.send("<button><a href='/auth'>Login With Google</a></button>")

// Auth
app.get('/auth' , passport.authenticate('google', { scope:
	[ 'email', 'profile' ]

// Auth Callback
app.get( '/auth/callback',
	passport.authenticate( 'google', {
		successRedirect: '/auth/callback/success',
		failureRedirect: '/auth/callback/failure'

// Success
app.get('/auth/callback/success' , (req , res) => {
	res.send("Welcome " +;

// failure
app.get('/auth/callback/failure' , (req , res) => {

app.listen(4000 , () => {
	console.log("Server Running on port 4000");

Now start the server by command and the server will start at port 4000: http://localhost:4000/

node index.js

Thus, Google authentication can be added to any website or app using Expressjs and passport.js.