TL;DR: This blog post compares and contrasts the popular JavaScript frameworks React and Next.js. React works well for SPAs and interactive UIs, while Next.js is good for SEO-driven websites and high-performance apps.
JavaScript is the language of the web. Due to its dominance on the web, it has given birth to numerous frameworks that help developers abstract necessary pain points, develop apps faster, and focus on business logic rather than worry about basic issues.
No framework is best; each one has its purpose and its strengths in the different areas of web development. As we say, there are n ways to solve a problem in computer science. Similarly, there are n different libraries or frameworks available, and none is the only one you need.
They can vary in the syntax and the way you will write the code, but the goal for each is to create the web application.
The framework you choose should be based on the nature of your application’s rendering strategy. This is the primary factor out of many others that you will have to consider while choosing a framework.
We can divide the rendering into two major groups:
As a software engineer, your purpose in choosing a framework or library is to get the job done with the fewest hurdles while at the same time meeting the technical requirements and future scalability.
While choosing a framework, you should consider solving engineering challenges like development speed, user experience, scaling, performance, SEO, etc., while considering the business, as well. Ultimately, whatever you do in software engineering will impact the business.
The following are the things that you should look for while choosing a framework:
While these technical factors are necessary to tackle engineering challenges, there are also a few general factors that you must consider while choosing a framework.
Community support comes from the adoption of the framework, and the adoption of the framework comes from the learning curve a framework has. Thus, the learning curve also becomes an important factor on the nontechnical side.
Taking the rendering strategy into consideration, along with all the previously listed technical and nontechnical factors, we are going to make a comprehensive comparison of the two most popular frameworks for web development currently: React.js and Next.js.
React is a powerful JavaScript framework (or library, as React refers to itself) that has changed how web development occurs. Over the years, it has become the foundation of countless websites that generate billions of dollars in revenue, including Facebook, Instagram, Airbnb, Netflix, and the list goes on.
This was made possible by the simplicity, reusability, and efficiency it offered developers through its component-driven development, one-way data flow, and virtual DOM, all of which help to create scalable and maintainable user interfaces.
React’s inception was to solve a core problem of web development that previous frameworks like JQuery could not solve, which was easing the DOM manipulation and boosting performance.
This framework was designed primarily for client-side rendering or the creation of single-page applications (SLAs). An SLA has one single HTML page, and all the page-building, action handling, and UI updates are handled through JavaScript, which is a static asset that is downloaded and cached on the client-side on the initial load along with the other assets such as media, fonts, etc.
There will be only an HTML page, and the routing on the client side is handled through JavaScript. The data from the server is fetched through the XHR request, and then it is re-rendered on the UI with the use of the virtual DOM that boosts the performance.
Using declarative JSX syntax allows us to write JavaScript functions as the HTML markup tag and use a virtual DOM to re-render only current changes to the browser. This syntax makes the website extremely fast and efficient. It makes React a go-to choice for the many developers who are building modern web applications.
Unlike traditional programming, where we follow the imperative approach of manipulating the DOM by accessing it through code and then manipulating it, React allows us to create that automatically updates and renders based on the change in the data.
The components are defined as normal JavaScript functions but can be accessed as regular HTML markup with the help of JSX, which stands for JavaScript XML. This helps developers treat the React components as HTML tags and define the clear purpose of each.
We can render a React custom component along with the native HTML. To use the React function as a JSX component, it should return JSX, which can be another React component or native HTML. Refer to the following code example.
import React from 'react';
const Heading = (props) => {
const {children, color} = props;
return <h1 style={{color}}>{children}</h1>;
};
export function App(props) {
return (
<div className='App'>
<Heading color="red">"Hello World!"</Heading>
<h2>Syncfusion blogs</h2>
</div>
);
}
Attributes passed to the JSX elements can be accessed as properties within the function. As you’ll notice, the color attribute is accessed as a prop used for styling. The children are a special prop that accesses the children passed to the JSX element.
All the JSX components can be self-closing, which is useful when you don’t want to pass the children to the elements. Refer to the next code example.
import React from 'react';
const Heading = (props) => {
const {text, color} = props;
return <h1 style={{color}}>{text}</h1>;
};
export function App(props) {
return (
<div className='App'>
<Heading color="red" text={"Hello World!"} />
<h2>Syncfusion blogs</h2>
</div>
);
}
The smallest block of the UI can be referred to as a component. React is a strong advocate of component-driven development, in which different UI blocks can be converted to components and then put together to create a module. These components can also be extended and behaviorally changed by accepting different properties.
Refer to the following code example.
import React from 'react';
const SocialLinks = () => {
return (
<div>
<ul>
<li>Twitter</li>
<li>Facebook</li>
<li>Linkedin</li>
</ul>
</div>
);
};
const Header = props => {
const { text } = props;
return (
<header>
<h1>{text}</h1>
</header>
);
};
const Footer = props => {
return (
<footer>
<section>
<ul>
<li>About us</li>
<li>Contact us</li>
<li>Privacy policy</li>
</ul>
</section>
<section>
<SocialLinks />
</section>
</footer>
);
};
export function App(props) {
return (
<div className='App'>
<Header text={"HelloW World!"}/>
<Footer />
</div>
);
}
React utilizes the power of the functional programming of JavaScript, in which the smallest piece of logic can be abstracted and encapsulated along with the overriding and overloading of the data.
In a unidirectional flow of data, the data is passed from the top to the bottom. In the case of React, the data is passed from the parent component to the child component, and so on, in a predictable manner.
Refer to the next code example.
import React from 'react';
const SocialLinks = (props) => {
const {color} = props;
return (
<div style={{color}}>
<ul>
<li>Twitter</li>
<li>Facebook</li>
<li>Linkedin</li>
</ul>
</div>
);
};
const Footer = props => {
const { color } = props;
return (
<footer>
<section>
<ul>
<li>About us</li>
<li>Contact us</li>
<li>Privacy policy</li>
</ul>
</section>
<section>
<SocialLinks color={color}/>
</section>
</footer>
);
};
export function App(props) {
return (
<div className='App'>
<Footer color={"red"}/>
</div>
);
}
React components have a lifecycle, where they maintain different stages of components like mounting, unmounting, and updating. React components update when their state or props change. State is what the component maintains itself as, and props are what it receives. As React follows a unidirectional flow of data, it is easier to predict what has caused a change in the component, where the data has come from, and what part it has changed.
What stands out about React is its implementation and usage of a virtual DOM. It uses a reconciliation algorithm in which React maintains an in-memory copy of the DOM. Whenever a React component updates, it takes a snapshot of the current virtual DOM and compares it with the updated virtual DOM to figure out what has changed and then only makes those changes to the actual DOM.
Repainting and reflowing are expensive operations on the webpage, and minimizing them drastically boosts performance. That is exactly what React does with the help of the virtual DOM.
In version 18, React introduced hooks, which are special functions within React components that have certain purposes, such as maintaining the state, handling the lifecycle side effects, and referencing the actual DOM element through JSX.
Refer to the following code example.
import React, {useState} from 'react';
export function Test(props) {
const [count, setCount] = useState(0);
return (
<div>
<button onClick={() => setCount(count+1)}>Click</button>
<div>Count: {count}</div>
</div>
);
}
As React components get re-rendered when they update, we can store values by declaring normal variables, as they will get redeclared every time the component updates. Thus, we have to use the useState() hook, which is specially designed to persist the values in the component.
As you can see in the previous component, we have set the default value 0 to the useState() hook. This hook returns two values, count, which is the current value, and the function setCount, which updates the value.
As the hook returns an array of values, we can define them as normal variables and give them any name.
On the button being clicked, the setCount() is called, which updates the value. Then, when React discovers a change in value, it re-renders the component.
You can also create custom hooks by following the rules defined for hooks:
The React Context API enables the storage and sharing of global data (like theming and user data) with the React components that are wrapped around the context provider without manually passing props down, also known as props drilling.
A module that holds a bunch of components can be wrapped around the context to share the data. The context acts as a centralized unit that manages the state and only the components that access the context will be re-rendered. This helps to avoid the unnecessary re-rendering of the components via which the props are passed around.
Refer to the next code example.
import {
createContext,
useContext,
useState,
} from 'react';
const defaultContextValue = {};
const BuilderContext = createContext(defaultContextValue);
export const BuilderContextProvider = (props) => {
const { children } = props;
const contextValue = useState({});
return (
<BuilderContext.Provider value={contextValue}>
{children}
</BuilderContext.Provider>
);
};
export const useBuilderContext = () => {
const context = useContext(BuilderContext);
if (!context) {
throw new Error(
'`useBuilderContext` must be used inside `BuilderContextProvider`',
);
}
};
While the context API provides more of the central state management capabilities, React comes with two other hooks for local state management:
The context API will maintain the state using these two hooks only, as ultimately we are creating only a component.
This state management is capable enough of scaling for a large enterprise application. You can, however, also use other external libraries, such as Zustand or Redux.
React is a powerful library that can be used for various use cases, but it excels in certain scenarios.
React was designed for creating applications that rely heavily on SEO. In cases where SEO is required, React can be used post-initial load of the HTML with hybrid rendering. React is best for:
Next.js is a React-based framework created by Vercel to provide a powerful and robust front-end framework for complete front-end web development. Where React.js was just a library, Next.js is a framework that enhances React’s capability for server-side rendering (SSR), static content generation (SSG), and API management.
The primary reason behind the creation of Next.js was to address the complexities of creating modern web applications, especially addressing the challenges around server-side rendering, routing, and performance optimization. React was designed only for client-side rendering, which has made developers rely on third-party libraries or external factors for server-side rendering, static content generation, and SEO optimizations. Next.js addresses these pain points by providing a streamlined solution for creating production-grade web applications.
Next.js was primarily designed to enhance React.js and provide features that React was missing.
Next.js provides built-in support for server-side rendering. The HTML page is prerendered on the server with all the content, and then it is returned to the browser, where it is parsed and rendered. This majorly improves the performance for content-heavy webpages and improves the SEO, as the crawlers can read the prerendered content better than the dynamically updated content on a single page.
Next.js also provides support for static content generation, where the pages are generated at building time. This way, when a request is made, the pages will be served instantly. To serve the pages, you can use CDN, as the content is already ready and we just have to serve it. This boosts the performance of the application and can be used for web apps that have content that hardly changes.
What if you want to pre-generate the webpages but still want to partially update the contents dynamically, which means we want to make use of both SSR and SSG capabilities? Next.js provides support for this with incremental static regeneration. This is where a pre-generated webpage can be incrementally updated as per requirement. This is helpful for websites like food delivery, where only partial content changes like the menu items for the restaurants in different outlets.
Next.js’s file-based routing mechanism makes routing easier. Any file defined under the pages/ directory will be treated as a route, and pages in Next.js are mapped to the file structure. This simple way of defining the routes removes the complexity and the overhead of handling the routes. In React, we had to rely on external libraries like React-Router for routing.
For example, if you create pages/contact-us.js, this will be accessible on the route /contact-us.
export default function ContactUs() {
return <h1>Contact Us</h1>
}
Any file named index.js will be available at the root of the directory by the Next.js router.
pages/index.js -> /
pages/contact-us/index.js -> /contact-us
This helps to define the router as a directory and abstracts all the common components within the directory. Similarly, you can also define nested routes, in which the nested file and folder structure will be treated as routes.
pages/blog/hello-world.js → /blog/hello-world
pages/blog/tech/hello-world.js → /blog/tech/hello-world
Next.js also provides a dynamic routing option that can be defined by declaring the file names in square brackets. This helps to avoid redundancy.
pages/blog/[id].js -> blog/1, blog/2
The dynamic routing feature allows more flexible and customizable route paths in the application. The paths can be accessed within the components and can be used to update the content dynamically.
Because Next.js is a server-side framework, it provides features to leverage the power of the server from itself. With API routing, Next.js enables you to develop the back-end APIs natively within the same codebase. These routes enable developers to write server-side logic and database operations, handle form submissions, and create REST APIs without the need for a separate backend, which is why Next.js is also called a full-stack JavaScript framework.
As Next.js supports file-based routing, any file defined under the directory /path/api/ -> /api/* will be treated as an API rather than a page.
export default function handler(req, res) {
res.status(200).json({ message: 'Next.js says Hello World' })
}
These files are excluded from the client-side bundle and are part of the server-side bundles.
Minimizing the initial load size of the bundle is crucial for faster page loading. Next.js automatically splits the code during bundle creation and serves the required JavaScript for each page. It lazy loads the JavaScript bundles on interaction or when required. The bundles are split into smaller chunks and loaded on demand, leading to faster load times and a better user experience.
Another golden feature that Next.js provides is built-in support for automatic image optimization. It handles all the common optimization techniques under the hood, such as automatically compressing images, serving responsive images, and lazy loading. This really helps reduce the load time of the pages, especially on flaky networks and mobile devices.
Next.js has created a custom component called next/image, which is a wrapper around the native HTML img tag that provides all the features out of the box.
import OptimizedImage from "next/image"
import usrImage from "../public/user.png"
const Profile = () => {
return (
<>
<OptimizedImage
src={usrImage}
alt="user profile image"
width={330}
height={330}
loading="lazy"
placeholder="blur"
sizes="(min-width: 60em) 24vw, (min-width: 28em) 45vw, 100vw"
/>
</>
)
}
Following is the list of the features that Next.js image components provide:
Next.js also provides capabilities for intercepting a request and response through the middleware and applying logic like validating the authentication and access token, etc.
Refer to the following code example.
import { NextResponse } from 'next/server'
export const config = {
matcher: '/contact-us/:path*',
}
// You can mark it as `async` if using `await` inside
export function middleware(request) {
return NextResponse.redirect(new URL('/', request.url))
}
Next.js is designed to integrate well with serverless and edge computing, enabling developers to serve the application globally using the CDN edges for lower latency and faster load times.
All paths in Next.js will cause middleware to run; you can configure the matcher to only run it on certain paths.
Middleware provides greater control over the application to manage the authentication, do logging, and handle access. It allows you to define custom logic for different routes or groups of routes.
Next.js has built-in support for SASS and CSS, using which developers can style their app without the need to do any extra setup or include an external library. Next.js takes out the overhead so a developer can focus on styling the app, and Next.js will apply conflict-free styles at both the global and module levels.
TypeScript has become the de facto standard. Its static typing helps to spot errors early and write predictable code, making it easier to develop an enterprise-level application. Next.js detects TypeScript files and compiles them at build time itself.
Internationalization is the practice of creating a multilanguage website and making the website available to different groups of audiences across the globe. Next.js simplifies the process of creating a website with global reach by providing a way to manage locales and configure route-based language handling without any requirement for an external library.
Next.js is a React framework designed to support all the future features of React, including the concurrent rendering in React 18. It allows for automatic batching of updates and features like Suspense and startTransition for a better and smoother user experience.
Next.js is the ideal framework when your project’s focus is on speed, search engine optimization, and ease of development using the capabilities of React. Next.js performs exceptionally well in these scenarios:
It may be a little confusing to decide which framework is right for you. As a developer, you can start with either of the two, as ultimately the syntax will be common, but both frameworks differ in their rendering strategies, performance, and SEO capabilities.
Your decision should be primarily based on the requirements of your projects, your team’s experience, and your long-term objectives.
React.js can be an ideal choice for projects where SEO is not a considerable factor. If you want to create a highly interactive web application quickly, React’s component-driven architecture can help. Also, React has huge community support, and tons of open-source libraries are available that help you create applications in no time with seasoned developers.
Next.js, which is built on top of the React, provides the React developer experience but extends its feature set with multiple rendering technologies such as static content generation (SSG), incremental static regeneration (ISR), and API routing to perform back-end operations within the framework. Next.js is considered a full-stack framework that is ideal for a project that requires performance enhancements, scalability, SEO optimizations, quick load speed, and dynamic data retrieval.
The selection of your framework should be based on the requirements of your project:
Both frameworks are great choices for creating a modern enterprise-grade application with efficient performance. Both have vast communities with excellent resources and a large set of libraries that will assist in getting unblocked on any issues.