No Duplicate Head

Prevent duplicate usage of <Head> in pages/_document.js.

Why This Error Occurred

More than a single instance of the <Head /> component was used in a single custom document. This can cause unexpected behavior in your application.

Possible Ways to Fix It

Only use a single <Head /> component in your custom document in pages/_document.js.

// pages/_document.js
import Document, { Html, Head, Main, NextScript } from 'next/document'

class MyDocument extends Document {
  static async getInitialProps(ctx) {
    //...
  }

  render() {
    return (
      <Html>
        <Head />
        <body>
          <Main />
          <NextScript />
        </body>
      </Html>
    )
  }
}

export default MyDocument

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