| name | Next.js Optimization |
|---|---|
| description | Image, Font, Script, and Metadata optimization strategies. |
| metadata | {"labels": ["nextjs", "optimization", "seo", "performance"], "triggers": {"files": ["**/layout.tsx", "**/page.tsx"], "keywords": ["next/image", "next/font", "metadata", "generateMetadata"]}} |
Optimization
Priority: P1 (HIGH)
Core optimization primitives provided by Next.js. Monitor First, Optimize Later.
Monitoring (Core Web Vitals)
Before applying optimizations, identify bottlenecks using:
- LCP (Largest Contentful Paint): Initial load speed. Target < 2.5s.
- CLS (Cumulative Layout Shift): Visual stability. Target < 0.1.
- INP (Interaction to Next Paint): Responsiveness. Target < 200ms.
- Tools: Chrome DevTools "Performance" tab,
next/speed-insights, orReact Profiler.
Images (next/image)
- Component:
<Image src="..." alt="..." width={500} height={300} />. - Features: Automatic resizing, lazy loading, format conversion (WebP/AVIF), and CLS prevention (placeholder sizing).
- Remote: Must configure
images.remotePatternsinnext.config.jsfor external URLs.
Fonts (next/font)
- Local:
localFont({ src: ... }). - Google:
Inter({ subsets: ['latin'] }). - Why: Self-hosts fonts at build time. Zero Layout Shift.
Metadata (SEO)
- Static: Export
metadataobject fromlayout.tsxorpage.tsx.
tsx
export const metadata: Metadata = {
title: 'Dashboard',
description: '...',
};
- Dynamic: Export
generateMetadata({ params })function.
tsx
export async function generateMetadata({ params }) {
const product = await getProduct(params.id);
return { title: product.name };
}
- Open Graph: Use
openGraphkey for social cards.
Scripts (next/script)
- Loading Strategy: Control when 3rd party scripts load.
strategy="afterInteractive"(Default): Google Analytics.strategy="lazyOnload": Chat widgets, low priority.