How To Build A Real-Time Chat App With MERN Stack?


The demand for real-time communication applications continues to surge, prompting developers to seek efficient and scalable solutions. Leveraging the MERN stack—MongoDB, Express.js, React.js, and Node.js—offers a robust framework for crafting such applications.

In this guide, we’ll explore the step-by-step process of building a real-time chat application using the MERN stack, empowering developers to create interactive and dynamic platforms that meet the evolving needs of users in today’s digital landscape.

Building A Real-Time Chatting App With MERN Stack

Building a real-time chat application with the MERN (MongoDB, Express.js, React.js, Node.js) stack is an exciting project that combines both front-end and back-end technologies.

Let us walk through the steps to create a simple real-time chat app using these technologies.

1.    Setup your Development Environment

Make sure you have Node.js and npm (Node Package Manager) installed on your system. Also, ensure MongoDB is installed or you have access to a MongoDB database.

2.    Initialize Your Project

Create a new directory for your project and navigate into it. Then, initialize a new Node.js project using npm:

“mkdir mern-chat-app

cd mern-chat-app

npm init –y”


3.    Set Up the Backend

First, let’s set up the backend using Node.js, Express.js, and for real-time communication.

Install required packages:

“npm install express mongoose”

Create a server.js file and set up Express server:

“const express = require(‘express’);

const http = require(‘http’);

const socketIo = require(‘’);

const mongoose = require(‘mongoose’);


const app = express();

const server = http.createServer(app);

const io = socketIo(server);


// MongoDB connection

mongoose.connect(‘mongodb://localhost:27017/chatApp’, { useNewUrlParser: true, useUnifiedTopology: true });


// Define MongoDB schema and models


 //Define routes


// logic


const PORT = process.env.PORT || 5000;


server.listen(PORT, () => {

  console.log(`Server running on port ${PORT}`);



4.    Set Up the Frontend

Now, let’s set up the frontend using React.js.

Create a React app:

“npx create-react-app client

cd client:”

Install required packages:

“npm install”

Replace contents of src/App.js with your chat application logic using React and

5.    Connect Frontend to Backend

In your React app, connect to the backend using client. Emit events to send messages and listen for events to receive messages in real-time.

6.    Style Your App

Use CSS or a CSS framework like Bootstrap to style your chat application and make it visually appealing.

7.    Test Your App

Test your chat application locally by running both the backend and frontend servers. Ensure that messages are sent and received in real-time.

8.    Deploy Your App

Once you’re satisfied with your chat application, deploy it to a hosting service like Heroku for the backend and Vercel/Netlify for the frontend. Make sure to set up environment variables for production.

9.    Enhance Your App

Consider adding features like user authentication, message encryption, file sharing, or message notifications to enhance the functionality of your chat application.

Building a real-time chat application with the MERN stack requires careful planning, attention to detail, and a solid understanding of both frontend and backend development. By following these steps and continuously iterating on your project, you can create a robust and scalable chat application to meet your users’ needs.

Benefits Of Using MERN Stack For App Development

The MERN Full Stack Developer Course offers several benefits for app development:

  1. Full JavaScript Stack: MERN stack allows developers to use JavaScript for both client-side and server-side development. This unified language approach simplifies development, reduces context switching, and promotes code reusability.
  2. Scalability: MERN stack is highly scalable, allowing applications to handle a large number of users and data. Node.js provides non-blocking I/O operations, making it suitable for building highly scalable and performant applications.
  3. Real-Time Web Applications: With technologies like, developers can easily implement real-time features such as chat, notifications, and live updates in MERN stack applications. This capability is crucial for building interactive and engaging web applications.
  4. Rich Frontend Experience: Js, a powerful JavaScript library for building user interfaces, is a key component of the MERN stack. React’s component-based architecture and virtual DOM enable developers to create dynamic, responsive, and feature-rich user interfaces.
  5. NoSQL Database: MongoDB, a NoSQL document database, is the default database choice for the MERN stack. Its flexible schema design, scalability, and ability to handle large volumes of unstructured data make it well-suited for modern web applications.
  6. Community and Ecosystem: The MERN stack has a large and active community of developers, which translates to extensive documentation, tutorials, and third-party libraries. This rich ecosystem simplifies development, accelerates the learning curve, and provides support for developers.

Overall, the MERN stack offers a powerful combination of technologies that streamline development, promote code efficiency, and enable the creation of robust, scalable, and feature-rich web applications.


In summary, building a real-time chat app as a Mern Stack Developer offers a dynamic and scalable solution for modern communication needs. By integrating MongoDB, Express.js, React.js, and Node.js, developers can create a feature-rich application with real-time messaging capabilities, providing users with a seamless and engaging experience.