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Iryna Deremuk
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Building a Real-time Chat Appwith React JS: Tips and Techniques for a Scalable App

Time to read: 9 min

Communication is the lifeblood of modern businesses, and real-time chat apps have proven to be
powerful tools for engaging customers and fostering connections. But the road ahead can be full
of challenges and complexities for business owners aspiring to create their own scalable chat app.

In this article, we'll guide you step by step through the development of a chat app using React JS.
From setting up the development environment to implementing real-time communication features,
we'll equip you with the knowledge you need to bring your vision of a chat app to life.

Understanding the Requirements of a Scalable Chat App

A scalable chat app is designed to handle a growing number of users, messages and interactions
without compromising performance or user experience. It's about implementing systems that can
handle growing volumes of data, simultaneous user interactions and real-time communications.

Why is building a chat app so complicated?

Many businesses quickly realize that it's a challenge to implement more complex or customized
features in a chat app. Let’s take a look at the main challenges that arise when developing
a real-time application.

Storing and Finding

We need an efficient way to search and edit messages. How should we store them?
What data structures make messages easily searchable? How do we enable users to
edit stored messages and ensure the data is reliably stored?

Chat app's messages storing and finding scheme

Authentication and Authorization

While some chat scenarios involve anonymous users, many require logging in with usernames, avatars
and other credentials. Each user has different permissions depending on their role. For example,
an admin user can create chat rooms, add or block users, delete messages and more.

Chat apps authentication and authorization principle

Complex Messages

Users expect specific actions and formatting when messages contain certain information.
When users are offline, push notifications should be sent. Also, they may want
shortcut commands like 'currently-active' to show the number of active users in the room.

A chat about an upcoming conference meeting

User Information

While a React JS chat app’s presence feature helps determine if a user is online, identifying profile
pictures, bios, and status messages can be more difficult. In addition, certain information about
the chat room needs to be displayed, such as whether a user is typing.


Imagine a chat room with 35,000 users where any status change triggers a message to inform others.
In rapidly switching scenarios, this could result in hundreds of millions of messages being exchanged
in a matter of seconds. Most businesses need help keeping up with such high message rates.

Here are some statistics to illustrate the challenge:
Over 80% of companies use chat apps like WhatsApp
for communication, meaning the competition is high.
Message storage and retrieval can take up to 10 times longer
in a large chat room without optimized data structures.
Chat apps often generate an enormous volume of messages.
For instance, WhatsApp users send over 100 billion messages daily.

As we can see, chat applications require robust solutions to handle
various complexities and scale effectively.

What is React JS, and How Does it Operate?

A scalable chat app is designed to handle a growing number of users, messages and interactions
without compromising performance or user experience. It's about implementing systems that can
handle growing volumes of data, simultaneous user interactions and real-time communications.

React JS popularity statistics
Here are some compelling statistics and examples to highlight the success of React JS
React JS has gained immense popularity, with over 10,245,189 downloads per week.
Facebook, Instagram, Netflix, Airbnb and many other tech giants
rely on React for their user interfaces.
React's virtual DOM updates and renders components efficiently,
resulting in a faster and smoother user experience.
React's component-based architecture promotes code reuse,
which reduces development time and improves maintainability.
React Native has enabled companies like Tesla, Bloomberg
and Instagram
to build powerful and performant mobile apps.

By using React JS, you can optimize your real-time chat app's UI, improve
the user experience and unlock the potential for cross-platform apps.

How to Build a Chat App With React JS

With its simplicity and effectiveness, React provides a robust framework for creating interactive
and engaging chat applications. We'll cover everything you need to know, from setting up the project
to implementing essential features like real-time messaging and user authentication.

By the end, you'll have the knowledge and tools to bring your chat app idea to life with the incredible
capabilities of React JS. Let's get started on your journey to building an impressive chat app.

React JS logo and a smartphone

Choose the Right Tools and Libraries

To develop a high-quality chat app in React JS that meets the diverse needs of users and industries,
chatbot app development companies must make critical decisions about infrastructure, protocols,
frameworks and programming languages. These decisions can either make or break the app
and impact the difficulty level and development time.

Frameworks play a vital role in messaging app development by providing functionality and reducing
manual work. Chat App Protocols and Message Markup Language (MML) are two widely used
frameworks for first-class messaging apps.

Development tools are also essential for efficient app creation. Popular choices among ReactJS
app development services are WebSockets & Socket.io, Chat Messaging APIs & SDKs, and Firebase.

When it comes to programming languages, the decision depends on factors such as development
approach, scalability and purpose. React JS offers a comprehensive library, including React Developer
Tools and Redux Developer Tools, making it ideal for scalable and responsive chat applications
in React JS. Language preferences and convenience are also important considerations.

Python, C#, Go, Java, PHP, Scala, Ruby and JavaScript are available for back-end programming
of messaging apps. For front-end coding, suitable choices are Flutter, Kotlin or Java (Android),
Swift (iOS), React Native (JavaScript) and React (JavaScript).

Among these options, React and React Native are excellent choices. React is great for web-based
messaging apps, while React Native is ideal for mobile versions, allowing code reuse on platforms
like iOS and Android.

React JS featuresReact JS Features

Create the Chat App Architecture

Now let's dive into designing the architecture for a real-time chat application.
It has to cover the following main functions
Chat: users can communicate with each other directly.
Type indicator: Informs the recipient when a user starts typing a message.
User status: Shows whether a user is online or offline.
This architecture is simple and easy to follow
and consists of a few essential components:
WebSocket server serves as the backbone of our application
and handles all communication between clients and chat rooms.
Room manager is responsible for managing the rooms in an application.
It takes care of creating, updating and deleting rooms. This component is located on the HTTP server.
User manager manages users within our application, including creating,
updating and deleting them. It's also located on the HTTP server.
Message manager manages the messages in an application. It exists on both the WebSocket and HTTP servers. This component stores incoming messages from WebSockets and retrieves all existing ones from the database when a user opens a chat room via the Rest API.
Chat ap architecture

With these components, we can build a robust architecture for our real-time React JS chat application
that ensures smooth communication and efficient management of users, rooms and messages.

Implement Real-time Functionality with React JS

Implementing real-time functionality is critical to building a dynamic and engaging chat app using
React JS. We'll go step-by-step on how to integrate these features into your application.

1. Setting up WebSockets

Implementing real-time functionality is critical to building a dynamic and engaging chat app using
React JS. We'll go step-by-step on how to integrate these features into your application.

2. Handling User Authentication

Before you get into real-time functionality, it's important to ensure user authentication and
authorization. Implement a secure system to verify users and grant them access to the chat app in
React JS. JSON Web Tokens (JWT) or other authentication mechanisms can be used for this purpose.

3. Emitting and Handling Events

With WebSockets you can trigger and process custom events for various chat actions. For instance,
when a user sends a message, you pass an event with the data to the server. On its side, you handle
the event by broadcasting the message to the appropriate recipients.

4. Updating the UI in Real Time

React's virtual DOM makes it easy to update the UI in real time when new messages or chat events
occur. Use React's state management capabilities to store and update chat data. Besides, event
listeners or hooks like useEffect help you handle WebSocket events and update the UI accordingly.

5. Typing Indicator and Online Status

Improve the user experience by implementing features like typing indicators and online status. When
a user starts typing, send an event to notify the other participants. Update the UI to show the typing
indicator in real time. Similarly, track and display users' online/offline status based on WebSocket connections.

6. Error Handling and Connection Status

Real-time functions may encounter errors or interruptions. Implement error-handling mechanisms
to solve connectivity problems, server failures or network disruptions. Display appropriate error
messages and give users the ability to reconnect or troubleshoot connection problems.

7. Scalability and Performance Optimization

As your React JS chat app grows, ensure its scalability and performance. Optimize the WebSocket
server and codebase to handle increasing traffic and support a growing number of concurrent users.
Consider load balancing techniques and caching mechanisms to improve performance.

Enhance User Experience with Additional Features

To truly captivate users, it's essential to go beyond the basics and include additional features that
enhance the overall chat experience. With React JS as your framework, you have the opportunity to
take your React JS chat application to new heights. Here are some exciting features that will make
your software stand out from the crowd:

Real-time Notifications
User Presence and Online Status
Message Editing and Deletion
Message Search and Filtering
Conversation History
Dark Mode and Theme Customization
Photos with three chatsEnhanced messenger example

By adding these extra features to your React JS chat app, you can greatly improve the user experience
and create a highly engaging platform. Tailor them to the needs of your target audience for maximum impact.

Test and Debug the Application

Testing and debugging your React JS chat app is vital to ensure smooth operation and optimal
performance. Start with thorough testing, subjecting your app to different scenarios and evaluating its
functionality. Test each component individually and then integrate them to check for compatibility
issues and unexpected behavior. This process puts your app through its paces to make sure it can
handle different situations without any hiccups.

Once testing is complete, you move on to debugging, where you identify and fix any errors or bugs
discovered during testing. This is like detective work, where you carefully examine the code and track
down the causes of problems. Use debugging tools and techniques to trace the data flow and identify
any areas that need attention.

Drawing of a man with a magnifying glass

Deployment and Monitoring

Once your app is ready, it's time to move it to a production environment, so the software is available to
your users. This process includes setting up servers, configuring databases, and deploying your code.
It's like launching a ship and preparing it to sail smoothly and serve its purpose. Make sure all
components are connected and functioning properly, and monitor the deployment process closely to
resolve any issues.

After deployment, monitoring is essential to keep an eye on your React JS chat app's performance
and detect potential problems. Use different tools to track server metrics, user activity and error logs.
By monitoring your app regularly, you can proactively detect and address any issues before they
impact the user experience. This will keep your React JS real-time chat app on track and ensure that it
runs smoothly and provides a reliable communication platform for your users.

Deployment and monitoring of Chat app


Building a scalable chat app with React JS requires a solid understanding of the app's requirements
and the technical skills to implement it effectively. The technology provides a powerful framework for
developing interactive and efficient real-time chat applications.

By following the steps outlined in this article, you can confidently embark on developing your own
chat app using React JS. From understanding the app requirements to leveraging the capabilities of
the technology, you now have the knowledge and tools to develop top-notch software that can
handle high volumes of users.

If you're planning to craft your own WhatsApp,
don’t hesitate to contact us.

Our experienced app developers will deliver a scalable
solution tailored to your business goals.

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