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What runtimes does Next.js support (Node.js vs Edge runtime)?

Q: What runtimes does Next.js support (Node.js vs Edge runtime)?

**TL;DR.** The **Node.js runtime** supports all Node APIs and is the **default** for rendering/handlers. The **Edge runtime** is a lightweight, **globally-distributed** V8 environment with **low cold starts** and a **limited API subset** (no native Node modules) — ideal for **Middleware** and latency-sensitive handlers. Node.js runtime full Node APIs DB drivers, fs default Edge runtime <text cla

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Full Node APIs vs lightweight global Edge.

nextjsedge-runtimenodejs-runtimedeployment

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Opt a handler into the Edge runtime

// app/api/geo/route.ts
export const runtime = 'edge';        // globally distributed, fast cold start

export function GET(request: Request) {
  const country = request.headers.get('x-vercel-ip-country') ?? 'US';
  return Response.json({ country });
}
// Note: no 'fs', no native Node modules here — Web APIs only.

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