What is ReactJS? (Uses, Features, and Examples)

Juan SalasJuan Salas

Juan Salas

ReactJS is a Javascript Library for building user interfaces. The library, backed by Facebook, became in open-sourced at JSConf US in May 2013. Being now the #1 frontend library for Web development, ReactJS' popularity is due to its relatively small learning curve, ease of dynamic app creation, versatility, adoption by leading companies around the world, and a robust and ever-growing ecosystem.

What is React.js and how to use it?
React JS makes it easy to keep track of changes made to the codebase.

Mobile and web applications are essential in our daily lives. Businesses worldwide use ReactJS and other coding tools daily to carry out any operation, from internal communications and sales to monetary transactions.

To be satisfactory in terms of user experience, web developers use tools that allow them to create websites that are as intuitive and agile for interaction as they are easy to code.

Among these tools is ReactJS: a robust open-source framework and library that enables the creation and modification of digital products through simple and efficient coding.

¿What is ReactJS?

ReactJS is an open-source, declarative JavaScript library that facilitates efficient user interface development and the creation of reusable components. It enables developers to create interactive web applications and helps businesses deliver high-quality, engaging customer experiences.

React component-based structure allows developers to break down complex UIs into easily manageable pieces. This way, they can customize them to fit the user’s needs.

It also has built-in optimization tools, such as React Fiber and React Native. Both tools help developers to create faster and more reliable applications.

ReactJS makes it easy to keep track of changes made to the codebase, allowing developers to identify and address any issues that may arise quickly.

A Brief History of ReactJS

ReactJS was created by Jordan Walke, a software engineer at Facebook, who released an early prototype of React called “FaxJS.” Tools like XHP, a straightforward PHP HTML component system, motivate React.

React's newsfeed was its debut application in 2011. Later, Instagram picks it up and incorporates it into its platform.

Over time, React creators and Facebook decided to release it as open source at JSConf US in May 2013. In 2015 JSConf, React Native was announced, enabling easy Android and iOS development. That year, developers made React Native an open source to support its expansion.

Features of ReactJS

React is the most extensively used library for building front-end mobile applications because of its exceptional features. Here is a list of those features:

1. Virtual DOM

The Document Object Model (DOM) is an essential part of the web since it divides it into modules and executes the code. Usually, the JavaScript Frameworks update the entire DOM at once, which causes slowness in the web application.

When not using React, websites often update the DOM through HTML. Although this system works well for static and simple sites, it is not for web pages and dynamic applications that require much user interaction.

In this sense, ReactJS uses a Virtual DOM, an exact copy of the real DOM. Developers use the Virtual DOM to see which parts of the real DOM should change when an interaction occurs (for example, when a user presses a button).

If a digital product doesn’t use ReactJS, the entire DOM would have to be updated to reflect even a small change (like a user comment), which means increased computing power and load time.

2. Reusable Components

In React JS, developers can reuse components (for example, pieces of UI) in various parts of an application to build more than one UI instance.

Reusable components allow developers to use an element without defining it multiple times. For example, a header or a button displayed on different pages.

These elements may be imported into current or future apps by building a library. Having the possibility of using reusable components is key to saving time and effort since these components are already created and tested.

3. Easy Debugging

Due to its popularity - and many developers using it - applications built with ReactJS are usually simple to build and easy to test. In fact, Facebook has enabled a browser extension that makes debugging React faster.

This extension within the Google Chrome web browser, which includes a React tab in the developer tools option, allows people to inspect the React components of the pages they visit directly.

4. Easy to start

React is designed for gradual adoption so that developers can use it according to the needs of each project.

Its dynamism allows developers to add to HTML pages in no time; furthermore, React’s presence can be expanded or limited to a few dynamic widgets.

One of the most significant advantages of this tool is that it has an Online Playground that allows developers to get familiar with its features in a safe environment with assistance.

In addition, it has a practical tutorial to learn by doing and a concept guide for those who prefer to understand the theory first.

Take a look at some examples of apps built with ReactJS.

5. Popularity among Developers and Adoption

React is relatively easy to learn, quickly making it a popular tool in the developer community. Those who want to learn how to use it only need a basic understanding of CCS and HTML.

Another significant advantage of React is that Facebook continues to maintain it. Therefore, it is constantly updated to speed up the interaction with its elements.

These advantages have led to a large community of developers using React. Simultaneously, it means constant support for new users to become familiar with this tool and easily find all the information they need.

A Statista study shows that ReactJS became one of the most requested web frameworks in 2022. Currently, 42.62% of web developers worldwide use it to develop web applications. Developers' demand for React will continue to grow in the following years.

According to The State of JS, React JS is the Front-End Framework with the highest retention ratio, interest, usability, and awareness. More and more people want - or need - to learn how to use it, and those who already know it would use it again.

What is ReactJS?
Ranking of Front-end frameworks and libraries by The State of JS.

Which companies are using ReactJS?

ReactJS has been the top choice for companies developing sustainable, reliable, and high-performance applications.

Thanks to this framework, many applications, and web pages have reached the top. The list of major companies using ReactJS is practically endless, but some are Facebook, Instagram, Dropbox, Netflix, Airbnb, Uber, Walmart, Rappi, etc.

For example, Dropbox built all its web and mobile apps using the React Native framework and ReactJS. This cloud storage and file synchronization service have benefited from the significant advantages of React, which has allowed them to:

  • Reduce file sizes
  • Increase reload speed
  • Develop user-friendly applications
  • An attractive appearance

Instagram started using ReactJs in 2015. Thanks to this tool, IG developers could improve the user interface and add a host of new features, including:

  • Search Engine Accuracy
  • Hashtag monitoring
  • Update and notifications in real-time

In short, React works perfectly to develop almost any digital product. From hospitality applications to e-commerce, websites, or social networks, this "all-terrain" tool allows to create of multi-platform applications that provide a satisfactory and adequate user experience.


1. What is ReactJS used for?

Developers use ReactJS to create online apps and interactive user interfaces (UI) faster and more effectively with less code than with just vanilla JavaScript.

2. Is ReactJS Front-end or Back-end?

React is a Front-end JavaScript library. It can create API calls that deal with the data and submit the request to the backend. React cannot process the data source or the database itself.

3. Which is Better: React or Angular?

ReactJS is easier to learn than Angular and provides a superior mobile cross-platform framework.

In addition, React is better than Angular due to its Virtual DOM.

Also, migrating between React's versions is very easy, unlike Angular, which demands installing updates one by one.

4. Which is Better: React or Vue?

Vue is better for building complex web apps for new developers than ReactJS. Besides, React documentation is a bit more challenging to read than Vue documentation.

However, both JavaScript frameworks have similar results. But React is still the most wanted web framework by experienced developers.


ReactJS is a safe bet to modernize your existing apps or create them from scratch.

Finding Talented ReactJS Developers and assembling a team for Web and Mobile Applications Development is simple.

Also, the features, existing ecosystem, and tools help cut costs and time-to-launch, solving many of the main challenges of Software Architecture.