Next.js App Router: 7 Practical Best Practices

The App Router is not just a new folder structure — it is a different model where components run on the server by default and the client bundle is something you opt into. Lean into that and apps get faster and simpler. Fight it and you get hydration errors and bloated bundles. Seven habits that keep projects healthy:

1. Keep "use client" at the leaves

Push interactivity down to small components (a button, a form) and keep pages and layouts as Server Components. This shrinks the JavaScript shipped to the browser.

2. Fetch data where you render it

Server Components can be async and fetch directly. Drop the useEffect + loading-state dance; fetch in the component that needs the data.

3. Stream with Suspense

Wrap slow sections in <Suspense> so the fast shell renders immediately and slow data fills in. Users see content sooner and crawlers get a fast first paint.

4. Use generateMetadata for SEO

Per-page titles, descriptions, canonical URLs, and OpenGraph tags belong in generateMetadata — server-rendered and crawlable, not stitched in on the client.

5. Be deliberate about caching

Know whether each route is static or dynamic. Set export const dynamic explicitly when data must be fresh, rather than being surprised by stale pages.

6. Co-locate loading and error UI

Add loading.tsx and error.tsx next to routes. You get skeletons and graceful failures for free, with no extra wiring.

7. Add structured data for content pages

For articles and listings, emit JSON-LD so search engines render rich results — a small file that pays back in visibility.

The App Router rewards thinking server-first. Ship JavaScript only where the user actually interacts.