Next.js 15 Performance Optimization Guide

Performance Optimization in Next.js 15

Performance is crucial for user experience and SEO rankings. This comprehensive guide covers advanced optimization techniques for Next.js 15 applications.

Core Web Vitals

Google's Core Web Vitals are essential metrics for measuring user experience:

• Largest Contentful Paint (LCP): Should be under 2.5 seconds
• First Input Delay (FID): Should be under 100 milliseconds
• Cumulative Layout Shift (CLS): Should be under 0.1

Image Optimization

Next.js provides excellent image optimization out of the box:

import Image from 'next/image'

export function OptimizedImage() {
  return (
    <Image
      src="/hero-image.jpg"
      alt="Hero Image"
      width={1200}
      height={630}
      priority
      placeholder="blur"
      blurDataURL="data:image/jpeg;base64,..."
    />
  )
}

Caching Strategies

Implement effective caching for better performance:

• Static Generation (SSG) for content that doesn't change often
• Incremental Static Regeneration (ISR) for dynamic content
• Edge caching with Vercel Edge Network
• Browser caching with proper cache headers

Bundle Optimization

Reduce bundle size with these techniques:

• Tree shaking to eliminate unused code
• Code splitting with dynamic imports
• Optimized package imports
• Webpack bundle analyzer for insights