Building a website with React.js: Everything you should know

Building a website with React.js: Everything you should know

Have you noticed how websites these days are so interactive and smooth? They react to every click, tap, and scroll with slick animations and load new content seamlessly without refreshing the entire page. This modern web experience is miles ahead of the static websites from the early days of the internet.

But what powers these websites and web apps? The answer is React.js, a popular open-source JavaScript library. It's used by tech giants like Netflix, Airbnb, and Instagram, as well as thousands of smaller companies worldwide.

But why exactly are websites that use React so well-loved? Buckle up, as this article will walk you through everything you need to know about React.js development.

How does React work?

Have you ever played with LEGO as a kid? The beauty of LEGO is that you can create anything by piecing together little colored bricks in different ways. React.js follows a similar philosophy — it lets you create user interfaces from tiny, reusable building blocks called "components."

You can build a basic UI component for a button or a dropdown menu and then reuse the same component wherever you need it across your application. Cost-efficient, isn’t it? You can keep adding more components, creating a diverse library of reusable UI elements. So, whether you build a complex website or a React single-page app, React.js lets you create UI parts separately. 

But how exactly does React.js enable efficiency with reusable components? Let’s switch to more tech details now.

Enabling component reusability

Each component in React is a self-contained unit that controls its own visuals and logic. When creating a component, you define its structure and any dynamic data it needs. For example, you could have a "Button" component that shows a clickable button with some text on it. 

React passes the necessary data to each component so it knows what to display. It also automatically updates the component whenever that data changes. This way, each component stays separate and focused on its own job.

You can easily customize reusable React components by passing in different data, combine multiple components together, or swap them in and out without breaking the rest of the UI. This modular approach is a core strength of websites that use React.

Reusable React components

Efficient rendering with React virtual DOM

Imagine you have a simple drawing on a piece of paper. It represents what's currently displayed on a website. If you want to make some changes directly on the paper, it can get messy, especially if you make many small changes.

Instead of changing the drawing itself, React creates a lightweight copy called a virtual document object model (DOM). So, when you make changes, React updates this copy first.

After making all the changes to the virtual copy, React can easily transfer them over to the real drawing on the paper (the actual DOM) in one go, keeping it neat and clean. Even with frequent updates, React virtual DOM ensures your app won't feel sluggish or bogged down.

Virtual DOM vs React DOM

Predictable state management

First, what exactly is a state in React? It’s all the data that defines what your app is displaying or doing at any given moment. For example, in a to-do app, the state would include the list of tasks, which tasks are completed, filtering options, and so on.

As we’ve found out, when you build a user interface, you break it down into reusable components. Some of these components naturally contain other components inside them. For example, the parent component would be a web form, while the child components — a submit button and an input field inside this form.

In React, data flows in a single stream, always from the top-level parent components down to the child components. This hierarchy makes it easy to understand where the data is coming from and how it will impact the different components.

As your website gets larger, you can stay in control of how the whole UI behaves and quickly identify and fix issues.

React component hierarchy

Now, let’s translate these React.js capabilities into a business language.

Benefits of React.js for businesses

So, why use React? Here are five big advantages you can get when making a website with React:

  1. Quicker launch. React.js's modular approach saves a ton of time and money. Instead of writing everything from scratch, you can simply customize existing components. The result? Your product hits the market faster.
  2. Speedy user experience. Nobody likes a slow, laggy website or app, right? React.js eliminates the number of redundant updates, ensuring a smooth experience, even for complex websites that use React.
  3. Built to scale and easy to maintain. React.js keeps things organized and manageable. Its component-based structure and predictable data flow prevent chaos. 
  4. Better teamwork and productivity. Different teams can work on separate reusable React components in parallel. No more stepping on each other's toes. New developers can get up to speed quicker, too.
  5. Industry-leading and future-proof. Maintained by Meta, React.js has a massive, active community. In 2022, 67.9% of respondents said they’d use React.js again. You can confidently invest in this framework, knowing it's here to stay.

While React is already pretty good at updating the UI parts, there are still situations where it’s necessary to optimize web development further using special techniques.

Optimizing React.js performance

As your website built with React gets more components and data, it may start to feel a bit slow or sluggish at times. This is where code splitting, lazy loading, React.memo, and useMemo can help.

React code splitting

Say you're building a huge eCommerce website with dozens of React pages and features. Sending the entire application code to the user's browser upfront would result in massive file sizes and slow load times. Not an ideal experience. 

With code splitting, you can break down your React application into smaller code chunks. Instead of serving the entire app at once, React will smartly load only the critical chunks needed for the initial page render. The remaining code is then lazily loaded as the user navigates to different parts of the app.

React code splitting

Lazy loading

Lazy loading takes React code splitting a step further by loading app components only when they're required. Let's say your website has a complex data visualization feature. With lazy loading, you can defer loading heavyweight components until the user actually needs to access them. Just like in a restaurant, you get drinks first and then the main dish. 

Lazy loading ensures users don't waste bandwidth and processing power on features they may never use during their visit.


Now, let’s find out when to use Rect.memo and what it actually is. Typically, a complex UI component doesn't actually need to update every single time your app state changes. For example, an image gallery doesn't change that often — it just shows the same set of images.

So, every time something else on the page updates, React will have to re-render or re-display that image gallery by default. Even though the gallery itself hasn't actually changed, React still has to spend time and effort redrawing those images again. 

React.memo is a built-in tool that helps prevent these unnecessary re-renders. Whenever React is about to re-render the gallery, React.memo checks if the actual image data going into the gallery has changed. If the images are still the same, React.memo simply says, "Hey, nothing important for this gallery has been updated, we don't need to redraw it right now."


While React.memo caches the rendered output, useMemo is used to cache the result of a calculation. Sometimes, parts of your website or app need to do data calculations behind the scenes. The problem is they can be very time-consuming.

If your website built with React had to redo all of those calculations every single time something on the screen updates or changes, it would quickly become slow and sluggish. With useMemo, you can do a calculation only once, and it will write down the solution.

The next time that same calculation needs to happen, instead of redoing all the work, you can simply refer back to the previous solution. A huge time-saver. 

In addition to rendering and calculation optimization strategies, some helpful state management tools exist.

State management tools

One of the biggest challenges front-end developers face with React is state management, especially in applications with many moving parts. React alone isn’t always sufficient to handle this complexity. That’s why some developers offering React.js development services use its built-in hooks, while others turn to a third-party state container, Redux.

React hooks useState and useContext

For smaller websites that use React or individual components that don't need to share a lot of data, you can use React's built-in hooks.

By using useState, you can give every component its own internal data storage. Since that particular component contains its own data, it‘s simpler to understand and update locally. However, if you have multiple components across your app that need to share and access the same data, you can use another hook called useContext. With its help, components can share common data across the entire app, regardless of their position in the family tree.

Using useContext in React

Yet, as more data flows between components, a tool like Redux may become more suitable to handle that increased complexity.


Redux provides a single, centralized location to store and manage the entire state of your website built with React — the Redux store. Whenever you need to change any data, like a user's profile information or items in a shopping cart, you send there a request (called an action).

The Redux store uses reducers to process these actions and determine how to update the data. For example, there might be a "user" reducer that handles all actions related to user data and a separate "cart" reducer that manages actions related to the shopping cart. After the appropriate reducers have processed the action, the Redux store updates its centralized state with the new data.

Redux promotes better code organization and reusability, as different components of your app can share and access the same state.

Redux store explained

While React is used for front-end development, it still needs to communicate with a backend system to fetch and send data. Let’s look at some methods for smoothly integrating your React.js application with the backend.

Seamless integration with backend technologies

The backend can be built using various server-side languages and frameworks, such as Node.js, Ruby on Rails, and Django. For the frontend (React) and backend to communicate and exchange data, they need a common language or protocol., whether when creating an app from scratch or adding React to existing project. 

This is where application programming interfaces (APIs) act as intermediaries. When building React websites, developers often rely on two main types of APIs: RESTful APIs and GraphQL. Let's explore the roles and benefits of each.

RESTful APIs: The tried-and-true way

RESTful APIs are called "RESTful" because they follow a set of principles or constraints known as "REST" (representational state transfer). These principles help ensure that the APIs are simple, scalable, and easy to understand.

Here's how they work: The backend organizes different types of data into separate "resources" or categories. For example, there might be a resource for product data, another for user data, and so on. When your React app needs to access a specific type of data, it sends a request to the corresponding resource's web address or endpoint. 

If your website built with React wants to retrieve or "get" data (like a list of products), it sends a "GET" request to that resource's endpoint. If it needs to add or "create" new data (like a new user signup), it sends a "POST" request along with the necessary details.

Rest API explained

Integrating RESTful APIs with React websites is generally a smooth process, since they follow standard protocols. However, as your React app gets bigger RESTful APIs might sometimes fetch too much or too little data than what's actually needed. This can lead to slower load times and performance issues, as unnecessary data is being transferred back and forth.

GraphQL: The modern approach

GraphQL is a newer approach to working with data in web applications. Unlike RESTful APIs, which have separate "categories" for different data types, GraphQL gives you a single, unified way to get precisely the data you need.

Let’s discover how GraphQL works. First, your React app describes the specific pieces of data it wants using a special query language. The GraphQL server (which is connected to the backend databases) then gathers all those requested pieces of data from various sources and sends back a response tailored specifically for your React app. 

For example, your eCommerce app needs to display product details along with customer reviews and seller information on the same page. With a traditional RESTful API, you might need to make multiple separate requests to fetch all that data.

So, one of the main benefits of GraphQL is that you can define a single query that asks for all those combined pieces of data in one go. The GraphQL server then fetches everything you asked for in that single query, allowing your React app to load faster.

GraphQL server operation scheme

However, since GraphQL is a newer technology, there might be a bit of a learning curve for developers who are used to traditional RESTful APIs. Additionally, setting up and maintaining a GraphQL server can sometimes be more complex than a standard RESTful API server.

Now, how about some examples of React.js in practice?

React.js web development use cases

React’s modular nature has made it applicable to a wide range of web development use cases. Let’s take a look at some of the best React websites. 


Netflix is a perfect React website example. The company made a really good call by using React.js for a huge chunk of their user interface, starting way back in 2015. And here’s why Netflix went with React:

  • Instead of constantly updating the actual website structure, which can get sluggish, the React virtual DOM only updates the parts that absolutely need changing. This makes the user interface smooth and responsive, which is massively important for Netflix's cinematic, visually stunning experience.
  • The component-based architecture in React allows the Netflix team to rapidly build brand-new features and design variations. They can easily test different user interface options through A/B testing. If a new version worked better, they could seamlessly swap it in. If not, they could cleanly remove it. This approach keeps the codebase nicely organized and scalable.
  • Another reason to choose React was that the same code can run on Netflix's servers and on users’ devices like phones or laptops. This eliminated much-duplicated work for their developers.

When you have millions upon millions of users accessing your platform worldwide, using React to build a website can be a valuable decision. Clearly, Netflix investing heavily in React.js has paid off in a big way for keeping their user experience top-notch.

Bus ticket booking software

GrandBus, an international bus company, brought us in to simplify ticket bookings online. Our team delivered a full custom software package — a slick website, an admin panel for the staff, and a mobile app.

For the website and admin panel, we decided React.js was the way to go, and that turned out to be the right move. React gave us everything we needed to check all the boxes for GrandBus:

  • We built them a modern, mobile-friendly website where customers can browse bus routes and book tickets in a few clicks. The React components let us streamline the development process while still keeping code clean.
  • The website loads quickly and performs well, even if someone has a slow internet connection. This is possible because of React virtual DOM feature.
  • We also developed an admin panel that is very powerful but still user-friendly for the GrandBus staff. They can manage everything from bus routes and ticket sales to contractors and reports, all from one central location.

This way, React enabled us to deliver GrandBus this rock-solid product right on schedule, even despite the tight deadlines they had. With the new React-powered website and systems, GrandBus is locked and loaded to start expanding their services down the road.

Online marketplace development services for booking experiential space

Our team at COAX also worked with a company called location:live to build their online marketplace website. For the front-end part of the website, we used React.js, too, and here are the results we got:

  • We were able to create a smooth experience for both the people renting spaces and the people offering their spaces. The smart search tools, handy filters, and simple booking process made it a breeze for renters to find and book the perfect venue for their marketing events. It also became very easy for the location owners to manage their offerings, list spaces, and take care of reservations.
  • React virtual DOM and component setup allowed everything to load quickly and run smoothly on the lo:live website. This meant users could effortlessly browse through the marketplace, even with tons of information and advanced features.
  • We made the code clean and easy to maintain. This was very important for a project with so many complex rules and interconnected pieces.

React.js was used in the development of lo:live to guarantee the marketplace could expand and change in response to future changes. It was a real win-win for everyone involved.

Future-proof your business with React services

A modern, lightning-fast website is no longer just a nice-to-have — it's essential for staying competitive. With React.js in your toolbelt, you'll be well-equipped to deliver engaging web experiences that keep users coming back.

Need a new React app built? Or an existing system modernized? We have a team of experts who’ve worked on various React.js projects and different React frameworks and know its ecosystem inside and out. Our software modernization solution approach ensures we use the latest React best practices.

For custom web development services, we're involved from start to finish. From planning to architecture, development, testing, and launching — COAX does it all.

Contact us to experience firsthand the potential of building a website with React!


1. What is React used for?

React is used for building user interfaces for websites and web applications. It allows developers to create reusable components that make up the UI. React.js makes it easier to build complex, interactive websites and web apps.

2. What is React Redux used for?

React Redux is a tool used along with React for managing the state (data) of a React application. As apps get larger and more complex, Redux helps developers better control and organize the app's state across different components.

3. What is the difference between React.js and Node.js?

React is a JavaScript library for building user interfaces that run in the browser. Node.js is a runtime environment that allows JavaScript to be run on the server-side or backend.

4. What is the difference between React.js and React Native?

 React.js is for creating websites and web applications that run in a browser. React Native uses similar concepts but is a framework for building mobile apps that run natively on iOS and Android devices.   

5. What are props in React?

Props (short for properties) are a way to pass data from a parent component down to a child component in React. They allow components to be reusable with different property values.

6. What are React websites examples?

Many companies use React for their user interfaces. Some examples of popular React websites include Netflix, Airbnb, Instagram, and the Facebook website itself.

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