nextjs

window/document not defined in SSR

ReferenceError: window is not defined|ReferenceError: document is not defined

Fixes

1.Wrap browser-only code in `if (typeof window !== 'undefined')` check
2.Use dynamic import with `{ ssr: false }`: `dynamic(() => import('./Component'), { ssr: false })`
3.Move browser-only logic into useEffect which only runs on client

ssrbrowser-apidynamic-import

Hydration failed because the initial UI does not match|Text content does not match server-rendered HTML

•Avoid using Date.now(), Math.random(), or browser APIs (window, localStorage) during initial render
•Use `useEffect` + state to render browser-dependent content only on client

You're importing a component that needs .+\. It only works in a Client Component

•Add `'use client'` directive at the top of the file that uses hooks, event handlers, or browser APIs
•Extract the interactive parts into a separate client component and import it

Error: Cannot use (useState|useEffect|useRef|useContext) in a Server Component

•Add `'use client'` at the top of the file
•Split into a server component (data fetching) and client component (interactivity)