Source URL: https://nextjs.org/docs/pages/building-your-application/routing/custom-document

Custom Document

A custom Document can update the <html> and <body> tags used to render a Page.

To override the default Document, create the file pages/_document as shown below:

import { Html, Head, Main, NextScript } from 'next/document'

export default function Document() {
  return (
    <Html lang="en">
      <Head />
      <body>
        <Main />
        <NextScript />
      </body>
    </Html>
  )
}

import { Html, Head, Main, NextScript } from 'next/document'

export default function Document() {
  return (
    <Html lang="en">
      <Head />
      <body>
        <Main />
        <NextScript />
      </body>
    </Html>
  )
}

Good to know:

_document is only rendered on the server, so event handlers like onClick cannot be used in this file.

<Html>, <Head />, <Main /> and <NextScript /> are required for the page to be properly rendered.

Caveats

The <Head /> component used in _document is not the same as next/head. The <Head /> component used here should only be used for any <head> code that is common for all pages. For all other cases, such as <title> tags, we recommend using next/head in your pages or components.
React components outside of <Main /> will not be initialized by the browser. Do not add application logic here or custom CSS (like styled-jsx). If you need shared components in all your pages (like a menu or a toolbar), read Layouts instead.
Document currently does not support Next.js Data Fetching methods like getStaticProps or getServerSideProps.

Customizing `renderPage`

Customizing renderPage is advanced and only needed for libraries like CSS-in-JS to support server-side rendering. This is not needed for built-in styled-jsx support.

We do not recommend using this pattern. Instead, consider incrementally adopting the App Router, which allows you to more easily fetch data for pages and layouts.

import Document, {
  Html,
  Head,
  Main,
  NextScript,
  DocumentContext,
  DocumentInitialProps,
} from 'next/document'

class MyDocument extends Document {
  static async getInitialProps(
    ctx: DocumentContext
  ): Promise<DocumentInitialProps> {
    const originalRenderPage = ctx.renderPage

    // Run the React rendering logic synchronously
    ctx.renderPage = () =>
      originalRenderPage({
        // Useful for wrapping the whole react tree
        enhanceApp: (App) => App,
        // Useful for wrapping in a per-page basis
        enhanceComponent: (Component) => Component,
      })

    // Run the parent `getInitialProps`, it now includes the custom `renderPage`
    const initialProps = await Document.getInitialProps(ctx)

    return initialProps
  }

  render() {
    return (
      <Html lang="en">
        <Head />
        <body>
          <Main />
          <NextScript />
        </body>
      </Html>
    )
  }
}

export default MyDocument

import Document, { Html, Head, Main, NextScript } from 'next/document'

class MyDocument extends Document {
  static async getInitialProps(ctx) {
    const originalRenderPage = ctx.renderPage

    // Run the React rendering logic synchronously
    ctx.renderPage = () =>
      originalRenderPage({
        // Useful for wrapping the whole react tree
        enhanceApp: (App) => App,
        // Useful for wrapping in a per-page basis
        enhanceComponent: (Component) => Component,
      })

    // Run the parent `getInitialProps`, it now includes the custom `renderPage`
    const initialProps = await Document.getInitialProps(ctx)

    return initialProps
  }

  render() {
    return (
      <Html lang="en">
        <Head />
        <body>
          <Main />
          <NextScript />
        </body>
      </Html>
    )
  }
}

export default MyDocument

Good to know:

getInitialProps in _document is not called during client-side transitions.

The ctx object for _document is equivalent to the one received in getInitialProps, with the addition of renderPage.

Custom Document

Custom Document

Caveats

Customizing renderPage

Customizing `renderPage`