Next.js Optimization
SKILL.md
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.export const metadata: Metadata = { title: 'Dashboard', description: '...', }; -
Dynamic: Export
generateMetadata({ params })function.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.