Next.js

Next.js is a collection of ready-made building blocks for constructing websites. Experts call something like this a framework: a basic structure that has already solved many standard tasks. Anyone who programs a website from scratch has to deal with hundreds of small details. These include things like the addresses of individual subpages or loading images at the correct size. Next.js provides a ready-made solution for all of this. It is developed by the company Vercel, and anyone may use it free of charge.

Why big companies rely on it

Loading time is money. Studies by major online retailers have shown the same connection for years: the longer a page takes, the more visitors abandon it. Even a delay of one second can measurably cost revenue. Next.js is designed precisely so that the first visible version of a page reaches the user very early.

The second reason is search engines. Google sends programs through the web that read the content of pages. On some modern websites, the delivered document initially contains almost nothing, because the content is only assembled in the browser. This can cause search engines to capture the page less effectively. That’s why Next.js already assembles the finished page on the server.

There’s also a practical point: many developers already know the system. Anyone wanting to build a team finds people more quickly. That’s why Netflix, TikTok, and numerous start-ups, among others, rely on Next.js. Many AI companies also build their chat interfaces with it.

Server and browser share the work

Next.js is built on React. React is a library developed by Facebook that is used to assemble interfaces from reusable parts. A menu, a button, a product card are such parts. React alone, however, mainly runs in the visitor’s browser. Next.js adds the server side.

The core issue is the question of where a page is created. With so-called server-side rendering, the server calculates the finished document for every request and sends it off. With static site generation, this happens beforehand, when the page is created. The result is then ready as a finished file and is extremely fast. Next.js masters both approaches and allows them to be mixed within the same project.

A common misconception: that Next.js is a replacement for React. That’s not true. It is an extension that adds server functions, an address system for subpages, and automatic optimizations to React. Images, for example, are automatically resized, and the program code is split into pieces. As a result, the browser only loads what is needed for the current page.

How to recognize a Next.js page

In everyday life, you encounter Next.js all the time without noticing it. Typical behavior when clicking: the page changes instantly, without the browser’s loading bar running through. The content is nonetheless immediately readable and doesn’t flicker afterward. Many online shops, news portals, and the user interfaces of AI services work this way.

In tech news, the name usually comes up in two contexts. One is Vercel, the company behind it, which also operates a hosting platform and earns money there. The other is discussions about dependency: a tool controlled by a single company makes many projects dependent on that company’s decisions. Changes to Next.js therefore regularly trigger heated debates in developer forums.

Anyone wanting to get started themselves doesn’t need any server knowledge. A single command in the terminal creates a ready-to-run project. This low entry barrier explains a large part of its widespread use.