Skip to content

How to add Google Analytics 4 to Next.js

Here’s how to add Google Analytics version 4 to a website based upon Next.js.

Create a Google Analytics property and save the property ID in a NEXT_PUBLIC_GOOGLE_ANALYTICS environment variable.

Then, you need to add a useEffect() call in the pages/_app.js file, which might look like this now:

import '/public/style.css'

function MyApp({ Component, pageProps }) {
  return <Component {...pageProps} />
}

Change it to

import { useEffect } from 'react'
import { useRouter } from 'next/router'

import 'tailwindcss/tailwind.css'
import '/public/style.css'

function MyApp({ Component, pageProps }) {
  const router = useRouter()

  useEffect(() => {
    const handleRouteChange = url => {
      window.gtag('config', process.env.NEXT_PUBLIC_GOOGLE_ANALYTICS, {
        page_path: url,
      })
    }
    router.events.on('routeChangeComplete', handleRouteChange)
    return () => {
      router.events.off('routeChangeComplete', handleRouteChange)
    }
  }, [router.events])

  return <Component {...pageProps} />
}

export default MyApp

Finally, add a pages/_document.js file that creates a Next.js custom document that injects the Google Analytics script, with:

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

export default class MyDocument extends Document {
  render() {
    return (
      <Html>
        <Head>
          <script
            async
            src={`https://www.googletagmanager.com/gtag/js?id=${process.env.NEXT_PUBLIC_GOOGLE_ANALYTICS}`}
          />
          <script
            dangerouslySetInnerHTML={{
              __html: `
            window.dataLayer = window.dataLayer || [];
            function gtag(){dataLayer.push(arguments);}
            gtag('js', new Date());
            gtag('config', '${process.env.NEXT_PUBLIC_GOOGLE_ANALYTICS}', {
              page_path: window.location.pathname,
            });
          `,
            }}
          />
        </Head>
        <body>
          <Main />
          <NextScript />
        </body>
      </Html>
    )
  }
}

Note: solution adapted from a post by Marie Starck on https://mariestarck.com/add-google-analytics-to-your-next-js-application-in-5-easy-steps/

→ Get my Next.js (pages router) Handbook

download all my books for free

  • javascript handbook
  • typescript handbook
  • css handbook
  • node.js handbook
  • astro handbook
  • html handbook
  • next.js pages router handbook
  • alpine.js handbook
  • htmx handbook
  • react handbook
  • sql handbook
  • git cheat sheet
  • laravel handbook
  • express handbook
  • swift handbook
  • go handbook
  • php handbook
  • python handbook
  • cli handbook
  • c handbook

subscribe to my newsletter to get them

Terms: by subscribing to the newsletter you agree the following terms and conditions and privacy policy. The aim of the newsletter is to keep you up to date about new tutorials, new book releases or courses organized by Flavio. If you wish to unsubscribe from the newsletter, you can click the unsubscribe link that's present at the bottom of each email, anytime. I will not communicate/spread/publish or otherwise give away your address. Your email address is the only personal information collected, and it's only collected for the primary purpose of keeping you informed through the newsletter. It's stored in a secure server based in the EU. You can contact Flavio by emailing flavio@flaviocopes.com. These terms and conditions are governed by the laws in force in Italy and you unconditionally submit to the jurisdiction of the courts of Italy.

Related posts about next: