How to use google analytics with next.js app?

In your _document.js you override the getInitialProps method. You can also override the render method. Simply add

  render() {
    return (
      <Html lang={this.props.lang || "en"}>
        <Head>
          <script
            dangerouslySetInnerHTML={{
              __html: `[google analytics tracking code here]`
            }}
          />
        </Head>
        <body>
          <Main />
          <NextScript />
        </body>
      </Html>
    );
  }

Make sure you import the required components:

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


Do not use the top answer here: using the native <script> tag is forbidden and it should be defined outside of the <head> tag.

This is the proper way to include a script tag and configure up Google Analytics in NextJS:

import Script from 'next/script'
import Head from 'next/head'

export default function Index() {
  return (
    <>
      <Head>
        <title>Next.js</title>
      </Head>
      <Script
        src="https://www.googletagmanager.com/gtag/js?id=GA_MEASUREMENT_ID"
        strategy="afterInteractive"
      />
      <Script id="google-analytics" strategy="afterInteractive">
        {`
          window.dataLayer = window.dataLayer || [];
          function gtag(){window.dataLayer.push(arguments);}
          gtag('js', new Date());

          gtag('config', 'GA_MEASUREMENT_ID');
        `}
      </Script>
    </>
  )
}

For more info: https://nextjs.org/docs/messages/next-script-for-ga


To setup Google analytics with NextJS using Typescript

I'm using below setup for my personal site (https://github.com/GorvGoyl/Personal-Site-Gourav.io) and it's working fine without any linting errors. Analytics is enabled only for production.

  • Create a Google analytics project and get Measurement ID.
  • In your NextJS project, create /lib/gtag.ts file and add your Google Measurement ID:
export const GA_TRACKING_ID = "<INSERT_TAG_ID>";

// https://developers.google.com/analytics/devguides/collection/gtagjs/pages
export const pageview = (url: URL): void => {
  window.gtag("config", GA_TRACKING_ID, {
    page_path: url,
  });
};

type GTagEvent = {
  action: string;
  category: string;
  label: string;
  value: number;
};

// https://developers.google.com/analytics/devguides/collection/gtagjs/events
export const event = ({ action, category, label, value }: GTagEvent): void => {
  window.gtag("event", action, {
    event_category: category,
    event_label: label,
    value,
  });
};
  • Also install gtag types:
npm i -D @types/gtag.js
  • Create /pages/_document.tsx:
import Document, { Html, Head, Main, NextScript } from "next/document";

import { GA_TRACKING_ID } from "../lib/gtag";

const isProduction = process.env.NODE_ENV === "production";

export default class MyDocument extends Document {
  render(): JSX.Element {
    return (
      <Html>
        <Head>
          {/* enable analytics script only for production */}
          {isProduction && (
            <>
              <script
                async
                src={`https://www.googletagmanager.com/gtag/js?id=${GA_TRACKING_ID}`}
              />
              <script
                // eslint-disable-next-line react/no-danger
                dangerouslySetInnerHTML={{
                  __html: `
            window.dataLayer = window.dataLayer || [];
            function gtag(){dataLayer.push(arguments);}
            gtag('js', new Date());
            gtag('config', '${GA_TRACKING_ID}', {
              page_path: window.location.pathname,
            });
          `,
                }}
              />
            </>
          )}
        </Head>
        <body>
          <Main />
          <NextScript />
        </body>
      </Html>
    );
  }
}
  • Create /pages/_app.tsx:
import { AppProps } from "next/app";
import { useRouter } from "next/router";
import { useEffect } from "react";
import * as gtag from "../lib/gtag";
const isProduction = process.env.NODE_ENV === "production";

const App = ({ Component, pageProps }: AppProps): JSX.Element => {
  const router = useRouter();

  useEffect(() => {
    const handleRouteChange = (url: URL) => {
      /* invoke analytics function only for production */
      if (isProduction) gtag.pageview(url);
    };
    router.events.on("routeChangeComplete", handleRouteChange);
    return () => {
      router.events.off("routeChangeComplete", handleRouteChange);
    };
  }, [router.events]);
  // eslint-disable-next-line react/jsx-props-no-spreading
  return <Component {...pageProps} />;
};

export default App;

More info: https://gourav.io/blog/nextjs-cheatsheet


Next.js since v11 recommends using their <Script> tag, and the right place to add it is the App component.

pages/_app.jsx

import React from 'react';
import Script from 'next/script';

const App = ({ Component, pageProps }) => {
  return (
    <>
      <Script
        src="https://www.googletagmanager.com/gtag/js?id=G-xxxxxxxxxx"
        strategy="afterInteractive"
      />
      <Script id="google-analytics" strategy="afterInteractive">
        {`
          window.dataLayer = window.dataLayer || [];
          function gtag(){window.dataLayer.push(arguments);}
          gtag('js', new Date());

          gtag('config', 'G-xxxxxxxxxx');
        `}
      </Script>

      <Component {...pageProps} />
    </>
  );
};

export default App;

You can see this solution working in nestjs-starter where I'm also setting the tag from an env var.

This will automatically log pageviews on navigation as well. If this doesn't suit you there's an official example with sending pageview events manually or a thread for doing so with React Router.

For sending custom events you can use window.gtag. It even has TypeScript support: @types/gtag.js

For v10 and lower use regular <script> tags according to Google's guide.

Tags:

Javascript

Google Analytics

Reactjs

Styled Components

Next.Js

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