What is Next.js?

Next.js is a framework built on top of React that gives you the flexibility of building scalable apps by allowing you to render content on the server.

Next.js is a full-stack framework. It helps you build both frontend and backend of an application. It provides node server out-of-the-box for building the backend of the application.

Next.js is The React Framework for Production, this means it provides you with all the features you need for production like hybrid static & server rendering, TypeScript support, smart bundling, route pre-fetching, and more.

Benefits of Next.js

1. Provides different rendering techniques: Libraries like React always perform client-side rendering but Next.js provides you with the additional option of server-side rendering. It provides three additional rendering techniques: Static Site Generation, Server-Side Rendering and Incremental Site Regeneration.

• Client-side rendering: Client-side rendering allows developers to make their websites entirely rendered in the browser with JavaScript. Instead of having a different HTML page per route, a client-side rendered website creates each route dynamically directly in the browser. In client-side rendering, you redirect the request to a single HTML file and the server will deliver it without any content (or with a loading screen) until you fetch all the JavaScript and let the browser compile everything before rendering the content.

• Server-Side Rendering: In Server-Side Rendering, the HTML of the page is generated on a server for each request. The generated HTML, JSON data, and JavaScript instructions to make the page interactive are then sent to the client. On every page refresh, the data is generated in the server and sent to the client. Eg: Dynamic news feed application.

• Static Site Generation: In Static Site Generation, the HTML is generated on the server, but unlike Server-Side Rendering, there is no server at runtime. Instead, content is generated once, at build time, when the application is deployed, and the HTML is stored in a CDN and re-used for each request. Eg: Blog posts and any static marketing websites.

• Incremental Site Regeneration: Incremental Site Regeneration gives you both the capabilities of Static Site Generation and Server-Side Rendering. It caches the result at build-time and shows the result when a request is made to the server. It has a 10-second time window, for any requests to the page after the initial request and before 10 seconds the old cached result is shown, but if the request is made after the 10-second interval still the old cached result is shown but a request is made to the server for new data in the background. When the response is received from the server the page will get updated with the new data and cached data will also be updated but if the response fails then still the old cached data is shown.

1. Built-in Performance improving features: Next.js has several built-in performance-improving features like code-splitting, minifying files, bundling, image-optimization, pre-fetching assets, etc.,

• Code-Splitting: It is a technique that helps you divide your web app into small chunks so you can only load the chunk that is used by the current page.

• Minifying files: Developers write code that is optimized for human readability. This code might contain extra information that is not necessary for the code to run, such as comments, spaces, indents, and multiple lines. Minification is the process of removing unnecessary code formatting and comments without changing the code’s functionality. The goal is to improve the application’s performance by decreasing file sizes. In Next.js, JavaScript and CSS files are automatically minified for production.

• Bundling: Developers break up their application into modules, components, and functions that can be used to build larger pieces of their application. Exporting and importing these internal modules, as well as external third-party packages, creates a complex web of file dependencies. Bundling is the process of resolving the web of dependencies and merging (or ‘packaging’) the files (or modules) into optimized bundles for the browser, with the goal of reducing the number of requests for files when a user visits a web page.

• Image-Optimization: Images make up a lot of our applications. So, optimizing images based on our requirement becomes one of the top priorities for improving the performance of our application. Next.js provides a lot of custom-built components for handling these types of situations and one of them is Image component from next/image. It is a custom-built component that optimizes the images present in the application based on the browser size. This helps in improving the performance of the application.

• Pre-Fetching Assets: Next.js fetches the assets when they are about to come into the viewport display. This helps in decreasing the page load times since the assets needed are already prefetched.

1. File-based routing: Next.js has its own routing system. Whenever we create a Next.js application, there is a folder called pages. The files and folders which are directly present inside the pages folder act as routes of our application.

2. SEO: SEO means Search Engine Optimization. Whenever an app is deployed on the internet, bots related to their respective search engines crawl through our website and try to understand the HTML of the website. Based on their understanding they try to rank our application with similar applications in their search engines and decide a rank for our application. Based on the rank our application would appear in the search results. A good rank means our application will appear in the top search results and will be easy to find. An SEO-optimized site would have the above advantage. Next.js provides various built-in components and techniques to easily optimize our sites for search engines.

3. Serverless function: Serverless functions are functions that start up a server upon function call and automatically shut down the server once the function is executed. In Next.js both the frontend and backend of the application can be coded in the same repository without any extra configuration. Any files which are inside the /pages/api folder act as serverless functions.

Conclusion

If you are a developer and have never used React, then it is better to first learn React. After getting comfortable with React and building some projects with it, you can try Next.js. As Next.js is an opinionated framework based on React, it gives you all the above-mentioned benefits out-of-box and makes your work simpler. It is not that you can't do the above things using plain React, you can achieve these functionalities with React also, but it would take a lot of effort and configurations. If your use case requires any of the above functionalities, then trying Next.js is a must.