| 1 | --- |
| 2 | title: Defer Non-Critical Third-Party Libraries |
| 3 | impact: MEDIUM |
| 4 | impactDescription: loads after hydration |
| 5 | tags: bundle, third-party, analytics, defer |
| 6 | --- |
| 7 | |
| 8 | ## Defer Non-Critical Third-Party Libraries |
| 9 | |
| 10 | Analytics, logging, and error tracking don't block user interaction. Load them after hydration. |
| 11 | |
| 12 | **Incorrect (blocks initial bundle):** |
| 13 | |
| 14 | ```tsx |
| 15 | import { Analytics } |
| 16 | |
| 17 | export default function RootLayout |
| 18 | return ( |
| 19 | <html> |
| 20 | <body> |
| 21 | {children} |
| 22 | <Analytics /> |
| 23 | </body> |
| 24 | </html> |
| 25 | ); |
| 26 | } |
| 27 | ``` |
| 28 | |
| 29 | **Correct (loads after hydration):** |
| 30 | |
| 31 | ```tsx |
| 32 | import dynamic from "next/dynamic |
| 33 | |
| 34 | const Analytics = dynamic |
| 35 | ssr: false, |
| 36 | }); |
| 37 | |
| 38 | export default function RootLayout |
| 39 | return ( |
| 40 | <html> |
| 41 | <body> |
| 42 | {children} |
| 43 | <Analytics /> |
| 44 | </body> |
| 45 | </html> |
| 46 | ); |
| 47 | } |
| 48 | ``` |