| 1 | --- |
| 2 | title: Dynamic Imports for Heavy Components |
| 3 | impact: CRITICAL |
| 4 | impactDescription: directly affects TTI and LCP |
| 5 | tags: bundle, dynamic-import, code-splitting, next-dynamic |
| 6 | --- |
| 7 | |
| 8 | ## Dynamic Imports for Heavy Components |
| 9 | |
| 10 | Use `next/dynamic` to lazy-load large components not needed on initial render. |
| 11 | |
| 12 | **Incorrect (Monaco bundles with main chunk ~300KB):** |
| 13 | |
| 14 | ```tsx |
| 15 | import { MonacoEditor } from './monaco-editor' |
| 16 | |
| 17 | function CodePanel({ code }: { code: string }) { |
| 18 | return <MonacoEditor value={code} /> |
| 19 | } |
| 20 | ``` |
| 21 | |
| 22 | **Correct (Monaco loads on demand):** |
| 23 | |
| 24 | ```tsx |
| 25 | import dynamic from 'next/dynamic' |
| 26 | |
| 27 | const MonacoEditor = dynamic( |
| 28 | () => import('./monaco-editor').then(m => m.MonacoEditor), |
| 29 | { ssr: false } |
| 30 | ) |
| 31 | |
| 32 | function CodePanel({ code }: { code: string }) { |
| 33 | return <MonacoEditor value={code} /> |
| 34 | } |
| 35 | ``` |
| 36 |