rsnext/docs/api-reference/next.config.js/cdn-support-with-asset-prefix.md

description
A custom asset prefix allows you serve static assets from a CDN. Learn more about it here.

CDN Support with Asset Prefix

To set up a CDN, you can set up an asset prefix and configure your CDN's origin to resolve to the domain that Next.js is hosted on.

Open next.config.js and add the assetPrefix config:

const isProd = process.env.NODE_ENV === 'production'

module.exports = {
  // Use the CDN in production and localhost for development.
  assetPrefix: isProd ? 'https://cdn.mydomain.com' : '',
}

Next.js will automatically use your prefix in the scripts it loads, but this has no effect whatsoever on the public folder; if you want to serve those assets over a CDN, you'll have to introduce the prefix yourself. One way of introducing a prefix that works inside your components and varies by environment is documented in this example.