Next.js vs React- An In-Depth Comparison for Modern Web Development

React and Next.js are the most talked about tools in web development. Even though they have a parent-child relationship each has its own set of strengths and is best suited for different types of projects. In this article, we’ll look at these two tools, what they are, compare them, and know their use cases.

What is React?

React is a JavaScript library for building user interfaces in software applications interfaces. In React, user interactions don’t require a full page reload and it is actively developed and maintained by Facebook, in collaboration with a dedicated community of developers and companies.

React applications use a component-based architecture design, which is reusable and independent. This approach fosters code reusability and maintainability.

How Does It Work?

React allows us to create modular and reusable user interfaces using its component-based architecture, breaking down the UI into distinct and manageable components.

These components can be class components that include state and lifecycle methods or functional components that use hooks for state management.

React uses JSX to define the structure of its components, allowing developers to write code that closely resembles HTML.


Another feature that makes React stand out is the use of a virtual DOM is one of React’s key optimizations. This lightweight representation of the actual DOM allows React to update the user interface efficiently by identifying and applying only the necessary changes. This process is known as reconciliation. It minimizes the number of manipulations needed in the real DOM, contributing to enhanced performance.


Features of React

Some key features of React include:

  • Declarative Syntax: React uses a declarative syntax, allowing developers to specify how the UI should look and behave. This makes the code more intuitive and understandable.
  • Component-Based Architecture: React uses a component-based architecture, which divides the UI into reusable and independent components. Each component manages its state. This makes it easier to maintain and update specific parts of the application.
  • Virtual DOM: React uses a virtual DOM to optimize the rendering process. Instead of manipulating the actual DOM directly, React creates a virtual representation and updates it efficiently. This improves performance and efficiency by minimizing unnecessary DOM manipulations.
  • Unidirectional Data Flow: React enforces unidirectional data flow, ensuring that data flows in just one direction in an application. This makes it easier to understand how data changes over time and helps prevent two-way data binding issues.
  • JSX (JavaScript XML): React utilizes a syntax extension for JavaScript that looks similar to XML or HTML. JSX allows developers to write UI components in a way that closely matches the final output, enhancing code readability.
  • Reusable Components: React’s component-based architecture promotes code reusability. With this, developers can create modular components that can be reused across various parts of the application, leading to more maintainable and scalable code.

Installing React

Create a new React application by running the command below:

npm create-react-app my react-app

Replace “my-react-app” with the desired name for your React application. Navigate to the React project directory and start the development by running the below command.

cd my-react-app
npm start

You can view your React app by opening http://localhost:3000 in your browser.

Next.js vs. React

It is worth noting that create-react-app depreciated. However, alternative tools, such as Vite or Remix, are recommended for creating new React projects.

Run the code snippet below to install the latest version of React:

npm create vite@latest

Start the development server by running the code snippet below within your terminal:

npm run dev

Project Structure

The project structure of a typical React application can vary depending on the project’s requirements and the team’s preferences.

However, there are several best practices for structuring a React application.

A React application’s ideal project structure would look like this:

my-react-app/

├── node_modules/

├── public/
│   ├── favicon.ico
│   ├── index.html
│   ├── logo192.png
│   ├── logo512.png
│   ├── manifest.json
│   └── robots.txt

├── src/
│   ├── App.css
│   ├── App.js
│   ├── App.test.js
│   ├── index.css
│   ├── index.js
│   ├── logo.svg
│   ├── reportWebVitals.js
│   └── setupTests.js

├── .gitignore
├── package.json
├── package-lock.json
└── README.md

Let’s go over the directory and files in the structure above:

  • node_modules/: This directory contains auto-generated files that your project relies on such as npm packages.
  • public/:  This directory includes static assets required by the web server, such as web icons and the index.html file.
  • src/: This directory includes your application’s source code. It includes sub-directories containing components, states and state management libraries and utility functions
  • package.json: This is the manifest file for your project, which contains information such as metadata (name, version) and the list of dependency packages.
  • package-lock.json: This file is automatically generated and contains the precise version of your installed dependencies for consistent installs across environments.
  • README.md: This is a markdown file that contains information about your project.

Please keep in mind that this is simply a sample framework that can be tailored to the demands of the project.

Some projects, for example, may have additional directories for utilities, hooks, or context providers.


React and ClientSide Rendering

Client-side rendering in React starts with a basic HTML page that is sent from the server to the client’s browser. This page is typically minimalistic, primarily containing a div element where the React application will be attached.

For example, the initial HTML might look something like this:

<!DOCTYPE html>
<html>
<head>
<title>Your React App</title>
<!-- Other head elements like meta tags, stylesheets, etc. -->
</head>
<body>
<div id="root"></div>
<!-- JavaScript files -->
<script src="path/to/your/react-app.bundle.js"></script>
</body>
</html>

The <div id= "root"></div> is where the React components get rendered into. Once the browser loads this HTML and the JavaScript files, React takes over.

The JavaScript executes, and React begins the process of rendering the application within the browser.

This is where the magic of CSR happens: React dynamically generates the HTML content and inserts it into the ‘root’ div.


Use Cases of React

Use cases of React are pretty numerous; below are some use cases of React:

  • Single-Page Applications (SPAs): React is extensively used for building interactive and dynamic SPAs where a seamless user experience is essential. Its component-based architecture and virtual DOM make it ideal for quickly managing complex UIs.
  • User Interfaces in Web Applications: React is commonly used to develop UIs for web applications, especially those with dynamic content that requires frequent updates. Its declarative syntax and quick rendering make it a popular choice for developing modern and responsive user interfaces.
  • E-commerce Platforms: React is widely used to create e-commerce websites and platforms. Its capacity to handle dynamic data, maintain states, and create a seamless user experience aligns well with the requirements of online shopping applications.
  • Content Management Systems (CMS): React is used to improve the user interfaces of content management systems, allowing content creators to interact with and manage their content seamlessly. Its modular structure is useful for building customized and user-friendly CMS interfaces.
  • Data Dashboards and Analytics Platforms: React is suitable for building data dashboards, analytics platforms, and solutions that require updates and interactive visualization. Its ability to efficiently handle state management and UI updates makes it well-suited for such applications.
  • Collaborative Tools and Applications: React can be used in building collaborative tools, such as project management apps, communication platforms, and collaborative document editing tools. Its real-time rendering capabilities and smooth UI updates help to create a positive user experience in collaborative environments.

To learn more about React, check “The Complete React Handbook”


What is Next.js?

Next.js is an open-source JavaScript framework for creating web applications and websites, particularly those that require server-side rendering (SSR) and efficient client-side navigation. It is built on top of React.

The React Framework for the Web

Next.js was created by Vercel, a platform for deploying web projects, and it has gained widespread adoption in the web development community.

Next.js simplifies the process of developing React applications by providing tools for handling common tasks such as routing, data fetching, and server-side rendering.


Features of Next.js

Some features of next.js include:

  • Server-Side Rendering (SSR): Next.js supports server-side rendering, which allows pages to be rendered on the server and sent as HTML to the client. This improves performance and SEO.
  • Static Site Generation (SSG): Next.js allows static site generation, which allows pages to be pre-rendered at build time, leading to faster loading times and reduced server load.
  • Automatic Code Splitting: Next.js automatically splits JavaScript code into smaller chunks, optimizing loading times by only fetching the code required for a specific page.
  • Client-Side Routing: It provides a simple and intuitive way for handling client-side navigation across pages, improving the user experience
  • API Routes: Next.js allows developers to define API routes within the project, making it easier to develop serverless functions and backend logic.

How it Extends react.js

Next.js extends React.js by building on its foundation and introducing additional features and conventions:

  • Server-Side Rendering (SSR): While React primarily renders on the client side, Next.js introduces server-side rendering, which provides a server-rendered HTML response for enhanced performance and SEO.
  • Static Site Generation (SSG): Next.js extends React by introducing static site generation, which allows developers to pre-render pages at build time, a feature that React does not have by default.
  • File System-Based Routing: Next.js extends React’s routing capabilities by introducing a file-system-based routing system, which simplifies page organization and navigation.

Installing Next.js

To install Next.js, open your terminal and navigate to the folder directory where you want to create your Next.js app. Then, run the following command :

npx create-next-app your-app-name

Don’t forget to replace “your-app-name” with the actual name you want to name your project.

Running this command will create a new Next.js app:

After running the command, navigate to the just installed folder:

cd your-app-name

To start the development server, run this command:

npm run dev

You can view your Next.js app by going to http://localhost:3000 in your browser.

Nextjs vs React

Next.js Folder Structure

In a typical Next.js project, the structure is quite distinct because of the nature of how Next.js works.

Below is a common next.js project structure:

my-next-app/

├── node_modules/

├── pages/
│   ├── api/
│   │   └── hello.js
│   ├── _app.js
│   ├── index.js
│   └── ...

├── public/
│   ├── favicon.ico
│   └── ...

├── styles/
│   ├── Home.module.css
│   └── globals.css

├── .gitignore
├── next.config.js
├── package.json
├── package-lock.json
└── README.md
  • node_modules/: This directory contains all of the code modules that your project relies on (npm packages), which are installed automatically.
  • public/:  This directory contains static resources that the web server can access directly.
  • pages/: This is a special directory. Each file inside this directory corresponds to one of your application’s routes. An example is pages/index.js, which corresponds to the / route, and pages/about.js, which corresponds to the /about route. The pages/api directory is used for defining API routes.
  • styles/: This directory contains the global styles for your application.
  • package.json: This is the manifest file for your project, which contains information such as metadata (name, version) and the list of dependency packages.
  • package-lock.json: This is a file that is automatically generated and contains the precise version of your installed dependencies for consistent installs across environments.
  • README.md: This is a markdown file where you can document information about your project

Next.js and Server-Side Rendering

Server-Side Rendering (SSR) in Next.js offers a different approach to rendering web pages compared to Client-Side Rendering (CSR) in React. It involves rendering the full HTML of a page on the server before then sending it to the client’s browser. This method offers a lot of advantages, especially in terms of initial page loading speed and search engine optimization.

When you access a Next.js application using SSR, the server processes your request and executes the React components to generate the HTML content of the page.

This process includes handling data-fetching operations, often using functions like getServerSideProps. The server then sends a fully formed HTML page to the browser, which includes the complete content of the page. When you inspect the source of a server-rendered Next.js page, you’ll see an HTML structure that might look like this:

<!DOCTYPE html>
<html>
<head>
<title>Your Next.js App</title>
<!-- Head content like meta tags, stylesheets, etc. -->
</head>
<body>
<div id="__next">
<!-- Fully rendered HTML content of your React components -->
<header>...</header>
<main>
<!-- Content specific to the page -->
</main>
<footer>...</footer>
</div>
<script src="path/to/your/next.js.bundle.js"></script>
</body>
</html>

In this structure, the div with the id __next is where the server-rendered React components reside. Unlike in CSR where this div would initially be empty and filled in by the client’s browser, in SSR, it contains the full HTML content as rendered by the server.

After the initial load, Next.js performs a process called “hydration” on the client side. During hydration, the React code takes over and attaches event handlers and other interactive elements to the server-rendered HTML, making the page fully interactive like a standard React app. This process allows subsequent user interactions to be handled client-side, providing a dynamic user experience akin to CSR.


Comparing React.js vs Next.js

Let’s directly compare various aspects of React.js and Next in this section:

React.js vs Next.js: Routing

In a React application, routing is handled on the client side using a library like react-router-dom. You can set up routing in a React application like so:

import { BrowserRouter as Router, Routes, Route } from 'react-router-dom';

export default function App() {
    return (
        <Router>
            <Routes>
                <Route path="/" element={<HomePage />} />
                <Route path="/about" element={<AboutPage />} />
            </Routes>
        </Router>
    );
}

In Next.js, routing is built-in and file-based. Each file inside the page’s directory corresponds to a route in your application. An example is a file named about.js in your pages directory; it would correspond to the /about route in your application.

You might link to different routes in a Next.js application like so:

import Link from "next/link";

const Header = () => {
  return (
    <nav>
      <Link href="/">Home</Link>
      <Link href="/about">About</Link>
    </nav>
  );
};

export default Header;

React.js vs Next.js: Data Fetching

In a React application, data fetching is handled in the component lifecycle using a method like fetch or a library like axios.

You can use the useEffect hook to fetch data when the component mounts like so:

import { useEffect, useState } from 'react';

const MyComponent = () => {
  const [data, setData] = useState(null);

  useEffect(() => {
    fetch('/api/my-data')
      .then(response => response.json())
      .then(data => setData(data));
  }, []);

  return (
    // render your data here
  );
};

In Next.js, data fetching can be handled in several ways depending on the needs of your application. You can choose to fetch data on the server side using getServerSideProps, or statically at build time using getStaticProps. You can fetch data at build time in a Next.js application like so:

export async function getStaticProps(context) {
  const res = await fetch('https://api.example.com/posts');
  const posts = await res.json();
  return {
    props: {
      posts,
    },
  };
}

export default function Blog({ posts }) {
  // render your posts here
}

React.js vs Next.js: State Management

State management can be handled in a React application using the built-in useState and useReducer hooks or external libraries like Redux.

You can use the useState hook to manage the state like so:

import { useState } from 'react';

const MyComponent = () => {
  const [count, setCount] = useState(0);
  
  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>
        Click me
      </button>
    </div>
  );
};

Next.js, being built on top of React, also supports the same state management methods as React. However, because it supports server-side rendering, using global state management frameworks like Redux might be difficult, as the state must be serialized and deserialized from the server to the client. But it’s not impossible, and there are examples showing how to integrate Redux in the Next.js repository.

Hey, before moving ahead, if you’re getting into the details of React and want to get a grip on managing state in React, I’ve got just the thing for you. I wrote a full guide on how to use Hooks, the Context API, and Redux. It’s super helpful for getting things clear in your head. Check out my In-Depth Guide to React State Management – it’s a great read if you’re looking to up your React game.”


React.js vs Next.js: Pre-rendering

By default, React doesn’t support pre-rendering, as it’s a client-side library. This means that all of your content is rendered in the browser, which can lead to slower load times and can make SEO less optimal.

Next.js, on the other hand, supports both server-side rendering (SSR) and static site generation (SSG), which are examples of pre-rendering. This means that your content can be rendered on the server before reaching the browser, resulting in improved SEO and faster load time.

Below are examples of how pre-rendering works through both server-side rendering and static site generation.

For SSR:

// pages/index.js

import React from 'react';

const HomePage = ({ serverRenderedData }) => {
  return (
    <div>
      <h1>Hello, Next.js SSR!</h1>
      <p>{serverRenderedData}</p>
    </div>
  );
};

export async function getServerSideProps() {
  // Fetch data from an API or database during server-side rendering
  const serverRenderedData = 'This content is rendered on the server-side using SSR.';

  // Pass data to the page via props
  return {
    props: { serverRenderedData },
  };
}

export default HomePage;

For SSG:

// pages/index.js

import React from 'react';

const HomePage = ({ staticGeneratedData }) => {
  return (
    <div>
      <h1>Hello, Next.js SSG!</h1>
      <p>{staticGeneratedData}</p>
    </div>
  );
};

export async function getStaticProps() {
  // Fetch data from an API or database during static site generation
  const staticGeneratedData = 'This content is statically generated at build time using SSG.';

  // Pass data to the page via props
  return {
    props: { staticGeneratedData },
  };
}

export default HomePage;

React.js vs Next.js: SEO Optimization

In traditional React, SPAs may face SEO challenges as search engines might struggle to index content rendered on the client side.

For example:

// Traditional React.js Component without Server-Side Rendering
import React, { useEffect, useState } from 'react';

const SinglePageApp = () => {
  const [data, setData] = useState(null);

  useEffect(() => {
    // Fetch data from an API (Client-Side)
    fetch('/api/data')
      .then(response => response.json())
      .then(data => setData(data));
  }, []);

  return (
    <div>
      {/* Render your data here */}
    </div>
  );
};

In the code above, we have a basic React component for a Single Page Application (SPA).

The data is fetched on the client-side using the fetch function inside the useEffect hook.

This demonstrates a typical approach in traditional React applications.

Next.js: With server-side rendering (SSR) and static site generation (SSG), Next.js on the other hand, improves SEO by providing pre-rendered HTML content that search engines can easily crawl and index.

For example:

// Next.js Component with Server-Side Rendering
import React from 'react';

const ServerSideRenderedPage = ({ data }) => {
  return (
    <div>
      {/* Render your pre-fetched data here */}
    </div>
  );
};

export async function getServerSideProps() {
  // Fetch data from an API or database (Server-Side)
  const data = /* ... */;
  return {
    props: {
      data,
    },
  };
}

export default ServerSideRenderedPage;

In the code above, we have a basic React component for a Single Page Application (SPA).

The data is fetched on the client side using the fetch function inside the useEffect hook.

This demonstrates a typical approach in traditional React applications.


React.js vs Next.js: Popularity and Community

React has a massive and active community with many resources, tutorials, and third-party libraries available. It boasts over 200,000 stars on GitHub. Making it one of the most used tools for web development.

The popularity of Next.js has grown significantly in recent years.

It has become a widely recognized framework with an impressive count of over 115,000 stars on GitHub, a thriving and expanding community, and a diverse range of available resources.


React.js vs Next.js: Availability of Plugins, Libraries, and Tools

React has a rich ecosystem of libraries and tools, including state management libraries (e.g., Redux), testing tools (e.g., Jest), and a variety of UI component libraries. Next.js has its ecosystem, including plugins and tools specifically designed for server-side rendering, routing, and deployment on platforms like Vercel. It also leverages the broader React ecosystem.


Pros and Cons of React.js and Next.js

In this section, we’ll examine their pros and cons.

Let’s start with React:

React.js

Below are some of the pros and cons of React.js:

Pros

  • Rich Ecosystem: When it comes to ecosystem, React has a vast and mature ecosystem featuring a wide range of libraries, tools, and community support.
  • Flexibility: React provides a high degree of flexibility, allowing developers to select their preferred state management, routing, and other tools.
  • Virtual DOM: The virtual DOM helps in rendering optimization by only updating the parts of the UI that have changed, improving performance.

Cons

  • SEO Challenges: Traditional React SPAs may face SEO challenges as search engines might struggle to index client-rendered content.
  • Boilerplate Code: Large React applications can accumulate boilerplate code, and setting up a project from scratch might require more configuration.
  • Learning Curve: For beginners, the learning curve can be steep, most especially when concepts like state management and hooks are introduced.

Next.js

Below are some of the pros and cons of Next.js:

Pros

  • Server-Side Rendering (SSR): Next.js provides built-in support for server-side rendering, improving performance and SEO.
  • Static Site Generation (SSG): The ability to generate static sites at build time can lead to faster loading times and reduced server load.
  • File-System Based Routing: Next.js makes routing more intuitive by simplifying it through a file-system-based approach.

Cons

  • Learning Curve: There might be a learning curve for developers new to the framework, especially if they are unfamiliar with server-side rendering techniques and concepts.
  • Less Flexibility: Next.js imposes more conventions and structure, which might be limiting for those who prefer more flexibility in choosing tools and configurations.
  • Complexity: As the application grows, the conventions and automatic features might add complexity that some developers might find unnecessary.

When to Use Them

In this section, we’ll take a closer look at when to use any of them.

React.js

When you need maximum flexibility and control over your project’s architecture, then you should consider using React. Also, you should opt for React if you are building a single-page application (SPA) and SEO is not a primary concern.

Another aspect is If you prefer a more lightweight solution without the additional features provided by frameworks like Next.js.

Next.js

Next.js is ideal if you want to benefit from server-side rendering and built-in static site generation. Also, If SEO is a critical factor for your application, Next.js is a strong choice. Another angle you should look at is when you prefer a more opinionated framework that streamlines the development process, then opt for Next.js.

Lastly, if you are building a full-stack application and want a more integrated solution for both frontend and backend development, choose Next.js.


Conclusion

In this article, we looked at React and how it works. We also looked at Next.js and how it works and compared them side by side according to factors like performance, community, SEO optimization routing, etc.

React.js and Next.js are powerful frameworks with distinct capabilities and use cases. Next.js extends React with server-side rendering and routing, making it an excellent choice for SEO-optimized applications. Choose the framework that best fits the needs of your project and your development philosophy.

References and Further Reading

Thanks for reading. If you enjoyed this blog and want to learn more about ReactJS and JavaScript, check out my recent articles.