Getting Started with Next.js 15: What's New

Introduction

Next.js 15 is a game-changer for modern web development. With significant performance improvements and developer experience enhancements, it's never been a better time to start building with Next.js.

Turbopack: Blazing Fast Dev Server

The biggest headline feature is the stabilization of Turbopack as the default dev server bundler. Compared to Webpack, Turbopack offers:

• Up to 76% faster local server startup
• 96% faster Fast Refresh (HMR)
• Instant route compilation on first visit

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# Turbopack is now the default
npm run dev
# Previously you needed the flag
npm run dev --turbopack

Improved Caching Strategy

Next.js 15 changed the caching defaults to be opt-in rather than opt-out. This means:

• fetch() requests are no longer cached by default
• Route Handlers are not cached by default
• Client Router Cache no longer caches page components

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// Now you explicitly opt into caching
fetch('https://api.example.com/data', {
  next: { revalidate: 3600 } // Cache for 1 hour
});

// Or use the new cacheLife API
import { cacheLife } from 'next/cache';

export default async function Page() {
  'use cache';
  cacheLife('hours');
  // ...
}

Enhanced App Router

The App Router continues to mature with:

• Partial Prerendering (PPR) — Mix static and dynamic content in the same route
• Server Actions improvements with better error handling
• Parallel Routes and Intercepting Routes refinements

Getting Started

Setting up a new Next.js 15 project is straightforward:

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npx create-next-app@latest my-app
cd my-app
npm run dev

Conclusion

Next.js 15 represents a major step forward in the React ecosystem. Whether you're building a portfolio, a SaaS product, or a full-scale application, these improvements make the development experience smoother and the end result faster.

The future of web development is exciting, and Next.js is leading the charge.