Top Next.js Interview Questions and Answers for 2025 Success

If you’re preparing for a web development job, especially one that involves React and server-side rendering, there’s a good chance Next.js will come up. With the rising popularity of this framework, knowing the top Next.js interview questions and answers can give you a serious edge in 2025.

In this blog post, we’ll walk you through commonly asked Next.js interview questions, explain them in plain language, and help you feel confident going into your next big interview. Whether you’re just starting or have a few years of React experience, there’s something here for you.

Let’s get started!

Why Next.js Skills Matter in 2025

Before diving into the questions, it’s essential to understand the “why.”

Next.js has become a go-to framework for building fast, scalable web applications. It’s built on top of React and offers features like server-side rendering (SSR), static site generation (SSG), and API routing, all out of the box. In fact, companies like Netflix, TikTok, and Hulu are already using Next.js to power parts of their platforms.

In 2025, with the launch of Next.js 14 and tighter integration with tools like Vercel, React Server Components, and the App Router, it’s more essential than ever to understand how the framework works.

All right, now let’s jump into the questions!

Common Next.js Interview Questions and Answers

1. What is Next.js, and how is it different from React?

Next.js is a React framework that adds extra functionality for building web applications, including routing, server-side rendering, and static site generation.

React helps you build UI components. But if you want routing, data fetching methods, or optimized performance, you’d have to add those manually. Next.js comes with these features built in.

Think of React as the engine and Next.js as the fully built car with doors, windows, and a GPS.

2. What are the key features of Next.js?

Next.js has several powerful features. Some of the most important ones are:

• File-based routing: Create routes just by adding files in the pages directory.
• Server-side rendering (SSR): Fetch data and render pages on the server.
• Static site generation (SSG): Generate HTML at build time.
• API routes: Build backend functionality right in your app.
• Image optimization: Built-in image component with lazy loading and resizing.
• Built-in CSS and Sass support: Easily add styles with no config.

Each of these helps Next.js stand out for building fast, SEO-friendly web applications.

3. What is the difference between getStaticProps, getServerSideProps, and getInitialProps?

All three are data-fetching methods in Next.js, but they work a bit differently:

• getStaticProps: Used for SSG. Runs at build time. Great for content that doesn’t change often.
• getServerSideProps: Used for SSR. Runs on every request. Ideal for data that needs to be up-to-date.
• getInitialProps: A legacy method that works on both server and client, but is now discouraged in favor of the others.

Tip: For static pages like blog posts, go with getStaticProps. For dashboards or user profiles, use getServerSideProps.

4. How does routing work in Next.js?

Routing in Next.js is file-based. That means every file you place inside the pages directory becomes a route.

For example:

– pages/index.js → /
– pages/about.js → /about
– pages/blog/[id].js → dynamic route like /blog/42

With the release of the App Router in Next.js 13+, routing can also be done inside the new app directory using layouts and React Server Components.

5. What’s the difference between the Pages Router and App Router?

As of Next.js 14, there are two routing systems:

• Pages Router: Traditional file-based routing using the pages directory.
• App Router: The new routing system that supports layouts, nested routes, and React Server Components. Defined in the app directory.

The App Router is the future of Next.js. It provides better performance and more flexibility but comes with a learning curve.

6. How does Image Optimization work in Next.js?

Next.js includes a built-in <Image> component that optimizes images automatically:

– Lazy loads images
– Resizes and serves them in modern formats like WebP
– Reduces bandwidth

All you have to do is import and use it:

“`jsx
import Image from ‘next/image’;

“`

It’s a simple way to improve page load speed.

7. What is Incremental Static Regeneration (ISR)?

This feature lets you update static pages without rebuilding the entire site.

With ISR, you can specify a revalidation time:

“`js
export async function getStaticProps() {
return {
props: { data },
revalidate: 60, // seconds
};
}
“`

This means the page will regenerate in the background at most every 60 seconds. Super helpful for blogs or product pages.

8. How do API Routes work in Next.js?

You can build backend APIs using files inside pages/api. Each file becomes an endpoint.

Example: pages/api/hello.js

“`js
export default function handler(req, res) {
res.status(200).json({ message: ‘Hello world!’ });
}
“`

This makes it easy to handle form submissions, emails, or database calls without setting up Express or another backend.

9. How does deployment work in Next.js?

You can deploy a Next.js app in several ways:

– Vercel: The creators of Next.js offer seamless deployment.
– Netlify & AWS: Also support Next.js.
– Docker/Custom Servers: For advanced setups.

Vercel is the easiest and preferred option. Just push your code to GitHub and connect the repo, it handles everything else.

10. What are React Server Components and how do they fit into Next.js?

React Server Components (RSC) let you render parts of your app on the server without sending extra JavaScript to the browser.

In Next.js 14, RSC is stable and used with the App Router. You create server components by default, and mark client components with `”use client”`.

This leads to leaner JavaScript bundles and faster load times.

Final Tips to Ace That Next.js Interview

Here are a few helpful tips before you walk into that interview room (or turn on Zoom):

• Build a small project. Interviewers love to see real-world examples. Try a blog or e-commerce site using Next.js.
• Understand the core concepts like SSR, SSG, and CSR, and when to use each.
• Brush up on the App Router. It’s the future of routing in Next.js, and employers want developers who can work with it.
• Prepare to discuss performance. Know how to optimize images, use middleware, and leverage caching for speed.

In Conclusion

Next.js continues to evolve rapidly, and as demand for high-performance web apps grows, companies are on the lookout for developers who can use it well. By preparing with these Next.js interview questions and answers, you’ll walk into your next opportunity feeling confident, and ready to impress.

Want to truly stand out? Try building a small project using the latest features like the App Router, React Server Components, and Image Optimization to really showcase your skills.

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