# Static Versus Dynamic Rendering — Next.js

Source: https://www.skillbyai.com/en/nextjs/d-static

> Build time or request time.

## What makes a route dynamic

By default Next.js prerenders routes as static when it can. A route becomes **dynamic** when it uses request-time information: cookies, headers, search params, or an explicit opt-in such as `await connection()` from `next/server`. Static pages are served from a cache with the content fixed at build (or revalidation) time; dynamic pages run on every request. Choose static for shared content and dynamic only where needed.

## Fresh enough, fast enough

Choose per route how fresh data must be, and let Next.js cache and revalidate the rest.

![Four ideas: static versus dynamic, prerendering, caching models, revalidation.](assets/figures/nextjs/section-4-map.svg) — Figure 4.1 — Static, prerendering, caching and revalidation.

## Two pages showing the time

This file is from a small demo store I built with Next.js 16.3.8, React 19.3 and TypeScript; `next build` compiled and type-checked it successfully. Both pages print the current time; the dynamic one awaits connection() to render on each request.

```tsx
// app/time/static/page.tsx
export default function StaticTime() {
  return <p>Rendered at {new Date().toISOString()}</p>;      // fixed at build time
}

// app/time/dynamic/page.tsx
import { connection } from "next/server";

export default async function DynamicTime() {
  await connection();                                         // opt into rendering per request
  return <p>Rendered at {new Date().toISOString()}</p>;
}
```

## Requesting each page twice, run

I built the demo store with `next build` (Next.js 16.3.8), started it with `next start` and requested pages with curl; the output is copied from that run, trimmed to the relevant lines. The static page shows the same time on both requests, the moment it was rendered at build; the dynamic page shows a new time on each request. The static and dynamic labels were added to the output for readability.

```bash
for i in 1 2; do curl -s localhost:3917/time/static; curl -s localhost:3917/time/dynamic; sleep 1; done
```

Output:

```
static : Rendered at 2026-10-01T21:26:15.615Z
dynamic: Rendered at 2026-10-01T21:26:32.961Z
static : Rendered at 2026-10-01T21:26:15.615Z
dynamic: Rendered at 2026-10-01T21:26:33.996Z
```

**Quiz:** Why did the static page show the same timestamp on every request?

- [x] It was rendered once at build time and served from cache
- [ ] The clock was broken
- [ ] Static pages render in the browser
- [ ] curl caches responses

*Answer:* It was rendered once at build time and served from cache. Static means rendered ahead of time.