Ultimate Guide to React.js Web App Development

User experience is now one of the most distinctive features of every business. It also has a tremendous influence on SEO and an indirect impact on traffic. And the quality of your website users’ experience hugely depends on the web technology you apply.

Developers had been trying to find the best ways to create fast and responsive interfaces for years. Finally, in 2013 Facebook engineer Jordan Walke came up with the solution that changed the perception of web development forever — React.js.

Though there might be many controversial opinions about this web technology, the number of React JS developers continues to grow. Do you know that, based on the React.js statistics, it is downloaded 12 193 665 times a week?

These numbers sound crazy, aren’t they?

According to recent statistics, 68,9% of developers that had used React.js before loved it. This article will probably convince you to use it too. You’re going to discover what React.js is, how it is different from other web development frameworks, and how to learn it. 

We will also guide you through the most famous websites built with React.js and review the list of advantages and drawbacks of using it. 

Prepare for the great React.js adventure. 

Intro to React.js

The web development area is constantly evolving. If not in 2013, React.js would have been introduced in 2014 since web development required a more complex solution for creating dynamic interfaces. So without further ado, let us get to the React.js overview.

What is React.js?

React.js or react js is one of the biggest and most popular component-based, open-source front-end Javascript libraries.

What is React.js used for?

React.js is used for both web and mobile development since it handles the view layer of the application. It provides developers with multiple reusable UI components for faster, easier, and more time-effective development. Less coding, more functionality, best rendering performance is what React.js is all about.

However, let’s dive deeper into the peculiarities and specifics of this technology by analyzing its features.

What are the features of React JS?

React.js technology wouldn’t be so popular if it weren’t for the features it provides. They are the reason React.js has a large community that only keeps growing.

JSX — JavaScript Syntax Extension

To avoid using complex JS DOM structures, React.js introduces the JSX (Javascript XML) — syntax extension to HTML. It enables developers to embed the HTML into the JavaScript code and use them in the same file.  

Isn’t it impressive?

Web developers use it to describe the appearance of the UI in the application or, in other words, how the interface should look. Using HTML structures in the same file with JS makes coding effortless and debugging — easier.

vDOM — Virtual Document Object Model

Document Object Model works with the HTML or XML document on the tree structure basis. Correspondingly, when any node representing the object of the web application changes, the whole document is updated. It is how DOM usually operates in most of the front-end development technologies. 

Unlike DOM, React.js keeps the virtual representation of the DOM in memory — vDOM. In other words, React replicates the page in virtual memory. When the component is changed, vDOM re-renders the user interface. 

Then it compares the previous state of the document and updates only those objects in the real DOM that were actually changed. Thus, it simplifies and speeds up the process of web development.

One-way Data Binding

To let developers get better control over the web application, React.js uses the one-way data binding, also known as a unidirectional data flow.  

It means developers can not apply any changes to the components directly. Instead, they add child components into the parent components and use the callback function to edit them.

It not only provides better control, facilitates debugging, and keeps everything structured but makes the application more efficient and flexible. 

React Native

One of the features of React.js we’ve decided to add to this list is React Native. It is a framework for mobile apps building that uses only JS. It has the same design as React and enables developers to use an extensive mobile UI library.

The UI building blocks in React Native are the same as in Android and iOS. So you have full access to their native features. You can even use React Native to utilize the components written in Java, Swift, and Objective-C.

This feature makes React.js an excellent choice for mobile apps development.

Component-based architecture

The development is much easier because of the component-based structure of React.js. It means that the application is divided into multiple maintainable components which have a unique logic. 

Moreover, different developers can work on different components simultaneously. They can pass the data within the app without affecting DOM. The component-based structure allows React.js developers to manage the reusable components and use them to create complex applications.

These features helped React.js make a change and get established as one of the top-notch web development technologies. 

What Is the Difference Between React And React JS?

Everything is very simple. React and React JS are slightly different names for the same thing and can be used interchangeably.

Top React.js Advantages

Now that we covered the basics of React.js and you know the key features that make it stand out, we should move to one of the best parts — React JS advantages. 

React JS is a dream come true for developers since it is fast, responsive, and flexible. However, this is not the only reason to use React JS. We prepared the list of benefits, so you can see why React.js is getting more and more popular each year.

Time-effective development

In some cases, it is crucial to deliver the result as fast as possible. Not to mention that the longer it takes to develop, the more expensive the application turns out to be. Unlike other web development frameworks, React JS allows multiple developers to work on different application components. Besides, they can be implemented without any issues. 

Moreover, compared to the other UI tools, React JS requires the least amount of built-in extra features. This leads to faster page load and fewer risks regarding integration issues. The user gets only what is needed.

Flexible code structure

One of the most significant advantages of React.js is the code structure it provides. All of the components are isolated and have unique logic. It enables easy implementation and faster integration. React.js technology correspondingly makes these components reusable. 

Why invent the wheel if you have it already invented, right?

Web apps are much easier to maintain and customize since developers don’t have to create the same component with the same logic repeatedly. They can just use these objects for different parts of the same application or even various applications.

High-performing application

The purpose of React.js is to provide dynamic and high-performing interfaces for a better user experience. In the DOM model, the CSS is recalculated, the layout is recreated, and the entire page is repainted every time the DOM changes. 

It is not very convenient since it requires some time to update.

React.js, on the other hand, provides virtual DOM and server-side rendering. Thus, when some object is changed, it is changed on the “virtual” side first. Then, only the modified object is re-rendered on the real DOM. This doesn’t take much time and provides faster application.

Custom UI components

Since React.js uses the JSX, it enables developers to create custom components. These components accept the HTML quoting that facilitates the subcomponents rendering. This way, web development on React.js is more diverse and universal.


Performance is known to be the essential SEO ranking factor. That’s what React.js is mainly used for. However, some search engine robots have difficulties analyzing JavaScript-heavy code.

The server-side rendering feature of React.js allows it to provide fast and dynamic interfaces. While the application runs on the server, the vDOM renders and returns the web page to the browser. There is no delay in page loading. The math is simple.

Growing community

One of the top React.js advantages is the community. Over the years, this convenient application development technology has grown dramatically. And hundreds of React JS developers are making it better every day. If you check GitHub, you’ll see that React has almost 36k forks and 177k stars. So if you plan to learn React.js, need advice or want to keep track of the news, there is much content on the topic and multiple specialists to consult.

Handy dev tools

Developing an application is just half the work. Facebook knows that. That is why they provided helpful tools for managing and supporting the apps. 

These React dev tools allow developers to inspect the hierarchy of React.js components, their present state or props, and check the parent and child components. So it is easier to scale and manage the applications in general.

One-way data binding

The structure of the data flow is one of those things that make React JS different. Since it uses a unidirectional data flow, child components can’t affect the parent ones. At the same time, in more complex JS-based frameworks, any change to the child component directly affects the parent. So React.js developers can just apply the changes and update the components without affecting any data, only the specified components. 

The Drawbacks of React.js

Now that you know about the pros of React.js technology, you might be convinced it is the best for the development of your web application. 

Don’t jump to conclusions too fast.

We still have some cons of React.js to consider, so you have a holistic view of this web technology before you consider it for your next project. 

React.js got traction very fast and was implemented by multiple developers over the years. However, some still can’t make their minds about it due to several reasons. So here are the drawbacks of React.js for you to consider:

Fast Development

The modern world is constantly evolving. New technologies appear every year and replace the old ones at a steady pace. And React.js is not an exception. A lot of different features of React.js are released daily, making it better and more stable.

However, it means developers have to learn daily and adjust to the changes really fast too. And while some might be fascinated by it, others consider it a disadvantage. They are not comfortable working with the technology they can never know enough of. 

Even the creators of React.js libraries, Michel Jackson and Ryan Florence, state:

In case you didn’t notice, we’re driving a car here with two flat tires, the hood just flew up in front of the windshield, and we have no clue what’s going on anymore! 


JSX syntax extension is one of the features of React.js you already know about. It simplifies the DOM modification, makes code more readable, and protects it from injections. 

However, while having no influence on user interface or performance, some developers still consider this a disadvantage of React.js. They think JSX is too complex and hard to learn. It is challenging for young developers to master React.js precisely because of the JSX.

Focus on UI

Usually, web applications are built on the MVC — model-view-controller pattern. As we’ve already mentioned, React.js is only responsible for the view part. 

Where are we going with this?

React.js being UI-focused means that you can’t develop a whole application with it. This library provides a lot of tools and components to help you develop the UI. However, you have to implement additional tools to cover the model and controller parts. 

Unlike some other Javascript frameworks, React.js is not a one-size-fits-all answer to your web development questions. And it is an obvious disadvantage.

Fast development, lack of documentation, complex JSX, and UI focus are considered to be the drawbacks of React.js only for some developers. Others continue to grow and create the best web applications and mobile apps following the fast development of React.js.

Top 10 Famous Websites Built with React JS

We’ve said it already but will repeat once more — React.js is becoming one of the leading technologies for web development. It enables developers to create dynamic and fast-performing interfaces.

Though we’ve just covered the disadvantages of React.js, it would be fair to mention that there are plenty of projects using this technology. Thus, to give you a broader picture, we’ve prepared a list of well-known websites that use React JS.


Yahoo is the third world’s largest search engine used by millions of people worldwide. However, the company provides other services as well on the Yahoo portal. One of them is Yahoo Mail. 

It is a React-based website that went a long way from HTML to PHP and Java. To keep up with the modern technologies and boost performance, developers decided to switch to React.js.

Now it is one of the fastest and more reliable mailing services on the web.


Another example of websites built with React.js is Discord. It is a free messaging application with a large audience that provides IP-based calls, video, and texting features. It is a place where people create communities to stay connected. 

Discord is most popular among students and gamers. The application with millions of monthly users benefits from the server-side rendering and vDOM features of React js. This way, no one gets interrupted while developers make changes.


To stay up-to-date with the latest news, people prefer to use trustworthy sources of information. CNN, one of the oldest news websites launched in 1995, fits just well. 

Time passes, and things change, but CNN never fails their users. That is why their website cleverly combines React.js with other web technologies. It provides hundreds of millions of their monthly users with a scalable, fast, and dynamic interface.


BBC is another world-famous news broadcasting company on this list. It also has one of the oldest news websites that gained the trust of millions through the years. 

BBC uses React.js to make sure their readers enjoy the responsive and powerful interface. Besides,React.js makes it easier for developers to come up with new features.


Another well-known React-based website is Paypal — an international electronic payment system that makes shopping and money transfers easier.

People are very serious when it comes to money matters, especially online. That is why they expect extra security from a company of that level. Correspondingly, developers use React.js as one of the most important assets of their tech stack.


Then there goes Airbnb. It is a hospitality service created for the community and around it to prove that travelling could be cheap. It is a website for tenants and landlords where you can list or book a nice place to stay anywhere around the globe.

The Airbnb website has a lot of blocks and sections to keep the interface dynamic. So, the feature React.js Airbnb developers enjoy the most is its component-based structure. Components can be reused, and code is easier to debug and refactor.


If you were to recommend the best streaming service, what would it be?

Undoubtedly, the first that comes to mind is Netflix, one of the best React JS projects. Netflix is popular not only because of the fine selection of TV shows. People enjoy the highly responsive and intuitive design as well. To get the most out of their platform, Netflix implemented React.js to reduce the initial load times, improve scalability, and boost overall performance.


Not surprisingly, Instagram — a photo and video sharing framework — is also on the list of best React JS websites. It is a single-page application with a lightning-fast dynamic interface. But that’s not all.

Instagram was built with React.js from the very beginning. Several Instagram features simply wouldn’t be possible without React. For example, progressive loading, Google Maps APIs, media storage, and geolocations. 


If you are a software developer, you probably know about this one. Atlassian is one of the leading providers of collaboration software for project managers and software developers. It is also a React JS project that uses it both externally and internally.

It would be strange if the software development company didn’t exploit the most popular JavaScript library to provide better solutions. The thing Atlassian benefits from the most is the ability to reuse libraries on different platforms.


As with the previous example, if you are a developer, you are probably familiar with Codecademy. It is a free online educational platform that provides coding courses in multiple languages for web and mobile app developers.

Codecademy developers try to keep up with the leading technologies. That is why they built a platform with React.js. Moreover, they are not afraid to experiment and implement consecutive parts to the existing React.js codebase. Besides, a component-based structure allows them to update separate UI components without disturbing the app’s work in general.


Angular vs React js. What is the difference?

React.js is a young technology that gained popularity fast. However, it is not the only one. There are multiple other Javascript frameworks developers use to create fully-featured web applications. Angular is one of them.

However, many developers can’t decide which one to use. So we decided to help you out and provide the comparison overview of React JS and Angular. Let’s dive deeper into the specifics of these two development tools.

React Vs Angular: Technical Overview

If you decide to choose between Angular and React js simply by consulting someone, it would not be a very wise decision. Each person has different opinions and preferences, and this also applies to web applications. 

To decide which technology to choose for the development, first of all, you have to analyze the technical side to make sure it suits your application best.


  • Angular is a fully-featured framework that comes with a lot of in-built features. This enables you to start the application development faster.
  • React JS is not a framework; it is an open-source JavaScript library that requires you to add other component libraries for testing, managing dependencies, calling APIs and more.

Data Binding 

  • Angular uses two-way data binding. It connects the DOM with model data, which results in updating both view and model. However, it negatively influences performance.
  • React JS uses one-way data binding. Developers implement child components within the parent ones. It minimizes the errors and simplifies the debugging. Besides, unidirectional data flow is faster.

Performance and DOM

  • Angular operated within the real DOM. In this case, the whole DOM is updated even with the smallest change. The entire data tree is re-rendered, which causes a delay. Also, additional configurations are required to update a specific element.
  • React JS operated within the virtual DOM. If some changes are added, they are compared with the real DOM. Then, only the changed elements are updated. It is way faster and doesn’t interfere with the app’s functioning.

Dependency Injections

  • Angular supports dependency injections. It provides a clean way of declaring dependencies for units (components, services, pipes etc). It also ensures the correctness of class instances and effective tree-shaking.
  • React JS does not support a dependency injection mechanism. But you always can provide your own implementation (if needed).

As you can see, React.js and Angular have their similarities and differences. However, to get to the point, we have to analyze some other features as well.

Angular Vs ReactJS: General Features 

Both Angular and React.js are powerful web development tools. However, there still are some distinctive features that make them applicable to the same project. Let’s analyze them.


Even though Angular is a more complex solution, React.js is still more popular among developers.

And this is not just word of mouth. According to Stack Overflow, React.js is more loved and used. 74.5% of developers prefer to work with React.js, while Angular has a lower preference of 57.6%. 

Some other statistics are:

Considering this, React wins this round in the React.js vs Angular battle.

Learning Curve

Agular is quite complex. Correspondingly it has a more complex component management system. The framework provides multiple solutions to the same problem. That is why it requires knowledge of the syntax and different concepts.

React.js, on the contrary, is easier to learn since all components are in the same file. Moreover, it is JS-based, so it requires less training than Angular.


Scaling an existing application with Angular is easy since it has plenty of built-in features, including a powerful CLI tool. 

React.js doesn’t have many features itself, which makes you rely on some third-party tools. However, you can still easily maintain the architecture with the React.js server-side rendering.

Development Lifecycle 

In React.js, developers create multiple components with a unique login first and then combine them into more complex ones. This way, when they change one component, the others are not affected.

In Angular, the application is extended from HTML to web development code that reduces the learning dependency.

In both cases, development is seamless and time-effective.


Because Angular is a framework, features are developed in a relatively small variety of approaches.

React, on the other hand, does not have restrictions on the solutions.

Angular VS ReactJS: Popular Use-cases

Though they seem similar, React.js and Angular are used for developing completely different applications. The following Use Cases describe it the best:

  • React.js Use Case
  1. Android and iOS Apps
  2. eCommerce Web Apps
  3. Social Networking Web-Sites & Apps
  • Angular Use Case
  1. PWA - Progressive Web Applications
  2. Enterprise Web Applications
  3. Single Page Apps with Dynamic Content

Angular Vs ReactJS: Who Wins?

After analyzing both sides of the coin, it is hard to come to a concise conclusion about which one is better: a fully-featured Angular framework or a faster and more convenient React.js library.

We know for sure that you should compare the features before choosing the best tool for web application development.


Top 5 Online Courses to Learn React.js 

The community of React.js developers constantly grows because this technology seems to be the future of web development. At this point, after grasping all that information, you might be wondering what the best way to learn React.js is. So we gladly present you the list of the best React JS online courses.

React JS Codecademy Course

Even if you have some basic knowledge of JavaScript and worked with other JS-based frameworks before, it might not be enough. You have to extend your knowledge, and there is no better way to do it than with the React JS Codecademy course.

It is a perfect start for beginners as the course covers React.js basics such as class and function components, lifecycle methods, JSX, and more. You can even get a certificate if you finish with the Pro.

Price: Free

Number of Blocks: 7

Time to Complete: 20 h

Times Completed: 301,129

Egghead.io: The Beginner’s Guide to ReactJS 

The best way to learn React.js is to get a solid basis. Thus, except for the previous course, you can take this beginner’s guide to React JS by Egghead. The instructor, Kent C. Dodds, will cover the essentials for the newbies and walk you through the whole process.

You will start with the blank index.html file and move it to the production-ready environment. Then, you will deploy your app at the end of the course.

Price: Free

Number of Blocks: 28

Time to Complete: 3 h 35 minutes

Times Completed: 6566

React Training: Advanced React.js

To master ReactJS basics might not be enough too, especially with the fast development. Once you know the basics, you have to dive into practice. 

This course includes lectures and exercises on the compound and higher-order components, render prop callbacks, and more.

It is the best React JS tutorial that gives you concise knowledge about multiple React components and their implementation.

Price: $50

Mastering React

If you want to learn more about real-life experience, practical shortcuts, and common mistakes, the Mastering React course is the best choice. Mosh Hamedany, who has more than 20 years of experience in software engineering, will walk you through the basics and provide some pro tips.

In this course, you will cover both theoretical and practical parts and acquire the skills necessary to start a career in React.js web development. You will simultaneously learn and build a video rental app. Mosh will even get you ready for React Native so you could enter the world of mobile development as well.

Price: $89–449

Number of Blocks: 8

Time to Complete: 19 h of video

Times Completed: 7,000

Please, note that the number of workshops and price depends on the package.

Epic React

Unlike other React JS online courses, Epic React is a series of workshops where you practice coding in a real development environment.

They cover the React basics in a course. However, it is mainly concentrated on more advanced topics like React hooks, advanced patterns, performance, building, and testing React apps.

As a bonus, you will get 10 hours of video conversations with top React experts who provide insights beyond the code.

Price: $69

Number of Blocks: 11, 220 lessons

Time to Complete: 13 h of video

Times Completed: 60,850

Each course has its unique benefits and provides you with valuable insight into React.js web development. Of course, one has to keep up and learn about the latest changes and releases since React.js develops by the day.


In Conclusion

Business goals and strategies change. So do the methods for achieving them. If you are in the world of web development but haven’t implemented React.js yet, try it. 

After analyzing all pros and cons, you will see that it truly is one of the leading progressive technologies for dynamic and fast-loading applications. 

JSX, vDOM, server-side rendering, and many other features this technology provides are great assets to your business strategy.

Thus, React.js enables you to boost your web development process that will pay off in the long run.

So why don’t you invest in it?