@next/next/no-before-interactive-script-outside-document

A beforeInteractive script must be in the HTML the server sends, before any Next.js code runs. In the Pages Router, only pages/_document.js writes that HTML. In a page or a component, the script isn't part of that HTML and loads later.

Files under an app/ directory aren't checked. In the App Router, beforeInteractive belongs in the root layout.

Configure

Off by default. To turn it on:

[lint.rules]
"@next/next/no-before-interactive-script-outside-document" = "error"

Examples

Reported:

import Script from "next/script";

export default function Home() {
  return <Script src="https://example.com/consent.js" strategy="beforeInteractive" />;
}

Not reported, in pages/_document.jsx:

import { Head, Html, Main, NextScript } from "next/document";
import Script from "next/script";

export default function Document() {
  return (
    <Html>
      <Head />
      <body>
        <Main />
        <NextScript />
        <Script src="https://example.com/consent.js" strategy="beforeInteractive" />
      </body>
    </Html>
  );
}

Not reported, in app/layout.jsx:

import Script from "next/script";

export default function RootLayout({ children }) {
  return (
    <html lang="en">
      <body>
        {children}
        <Script src="https://example.com/consent.js" strategy="beforeInteractive" />
      </body>
    </html>
  );
}