Edge Runtime Overview

The Edge Runtime is a lightweight JavaScript runtime that runs code closer to your users, at the edge of the network.

Benefits

• Lower latency: Code runs in data centers near users.
• Faster cold starts: Lighter than Node.js.
• Global distribution: Automatic worldwide deployment.

Enabling Edge Runtime

For Route Handlers:

typescript
export const runtime = 'edge';

export async function GET() {
  return Response.json({ message: 'Hello from the edge!' });
}

For Pages/Layouts:

typescript
export const runtime = 'edge';

export default function Page() {
  return <h1>Edge-rendered page</h1>;
}

Limitations

The Edge Runtime doesn't have access to all Node.js APIs:

• ❌ fs (filesystem)
• ❌ child_process
• ❌ Native Node modules
• ✅ fetch
• ✅ crypto.subtle
• ✅ TextEncoder/Decoder