Next.js vs React for SaaS Applications

React is a library; Next.js is a framework built on it. For most SaaS products today, Next.js is the better default — but it's worth understanding why.

Routing & structure

Plain React (e.g. with Vite) leaves routing to you — usually React Router. Next.js ships file-based routing with the App Router, layouts, and nested routes out of the box, which keeps a growing SaaS organized.

SEO & rendering

A plain React SPA renders client-side, which hurts SEO and first-paint. Next.js does server-side rendering and static generation, so your marketing pages, pricing, and docs rank — critical for a SaaS that needs inbound traffic.

Data fetching & server code

• Next.js server components + server actions let you query the database without a separate API layer.
• Plain React needs a backend/API you build and host yourself.
• Next.js route handlers cover webhooks and APIs when you do need them.

When plain React is fine

An internal tool or an app embedded behind auth (no SEO needs) can do well as a Vite + React SPA. For a public-facing SaaS with marketing, pricing, and content, Next.js wins.

KitCraft templates are built on Next.js 15 for exactly these reasons — SSR for SEO, server actions for data, and a clean App Router structure.