Solving Hydration Errors in Next.js Apps

# Solving Hydration Errors in Next.js Hydration errors happen when server-rendered markup doesn’t match the client-rendered markup. ## Common Causes - Using `Math.random()`, `Date.now()`, or browser APIs like `window` or `navigator` during render. - Timezone differences when rendering dates. ## Example Fix Before: ```tsx

{Date.now()}

``` After: ```tsx 'use client'; const [now, setNow] = useState(''); useEffect(() => { setNow(new Date().toISOString()); }, []); return

{now}

; ``` ## Best Practices - Avoid dynamic content on the server. - Use effects/hooks for browser-specific logic. - Wrap conditional rendering with `typeof window !== 'undefined'`. ## Conclusion Fixing hydration issues improves your app’s stability and SSR experience.