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Bundle Defer Third Party

Source: .agents/references/coding-standard/vercel-react-best-practices/rules/bundle-defer-third-party.md

Metadata​

  • title: Defer Non-Critical Third-Party Libraries
  • impact: MEDIUM
  • impactDescription: loads after hydration
  • tags: bundle, third-party, analytics, defer

Content​

Defer Non-Critical Third-Party Libraries​

Analytics, logging, and error tracking don't block user interaction. Load them after hydration.

Incorrect (blocks initial bundle):

import { Analytics } from '@vercel/analytics/react'

export default function RootLayout({ children }) {
  return (
    <html>
      <body>
        {children}
        <Analytics />
      </body>
    </html>
  )
}

Correct (loads after hydration):

import dynamic from 'next/dynamic'

const Analytics = dynamic(
  () => import('@vercel/analytics/react').then(m => m.Analytics),
  { ssr: false }
)

export default function RootLayout({ children }) {
  return (
    <html>
      <body>
        {children}
        <Analytics />
      </body>
    </html>
  )
}