Next.js Interview Questions and Answers
Next.js is the most common React framework in interviews. Here are the questions and clear answers.
What rendering strategies does Next.js support?
CSR, SSR, SSG and ISR — chosen per route. It also adds React Server Components and streaming in the App Router, so you can mix static, dynamic and interactive UI.
What are React Server Components?
Components that run on the server and ship zero JS to the browser — great for data fetching and static content. Interactivity lives in Client Components marked with 'use client'.
What is ISR?
Incremental Static Regeneration — statically generated pages that re-generate in the background on a schedule, giving static speed with periodic freshness.
What is hydration and a hydration mismatch?
Hydration is React attaching event listeners to server-rendered HTML. A mismatch is when the client render differs from the server output (e.g. using Date.now() or window during render).
App Router vs Pages Router?
The App Router is the modern model — Server Components by default, nested layouts, streaming and colocated data fetching. The Pages Router is the older file-based routing.
Master modern rendering
Rendering strategies, RSC, streaming and system design — in the Complete Frontend Kit's System Design Handbook.
⚡ Get the Complete Frontend Kit → ₹499Frequently asked questions
- When would you choose SSR over SSG in Next.js?
- SSR for dynamic, per-request, SEO-critical pages; SSG/ISR for content that rarely changes. Justify by user need, not hype.
- Do I need to know Server Components?
- Increasingly yes — the App Router is server-first, and RSC is a common modern-React topic.