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Custom Code to Add a Google Analytics Tracking ID in WordPress

Jan T • Jan 30, 2025 • Analytics Integration
How do I track my website visitors with Google Analytics on WordPress?
What is the code snippet to programmatically insert a Google Analytics tracking ID into the header of a WordPress theme without using a plugin?
Andy answered • Jan 30, 2025

Adding Google Analytics to WordPress

Custom Code Solution

Add this code to your theme's functions.php file or a site-specific plugin. It inserts the Google Analytics 4 tracking code in the <head> section of your website:

function add_google_analytics() {
    // Replace GA_MEASUREMENT_ID with your actual Google Analytics 4 tracking ID
    $tracking_id = 'GA_MEASUREMENT_ID';
    ?>
    <!-- Google Analytics 4 tag -->
    <script async src="https://www.googletagmanager.com/gtag/js?id=<?php echo esc_attr($tracking_id); ?>"></script>
    <script>
        window.dataLayer = window.dataLayer || [];
        function gtag(){dataLayer.push(arguments);}
        gtag('js', new Date());
        gtag('config', '<?php echo esc_attr($tracking_id); ?>');
    </script>
    <?php
}
add_action('wp_head', 'add_google_analytics', 10);

Alternative Solution (Universal Analytics)

If you're still using the older Universal Analytics (UA), use this code instead:

function add_universal_analytics() {
    // Replace UA-XXXXX-Y with your actual Universal Analytics tracking ID
    $tracking_id = 'UA-XXXXX-Y';
    ?>
    <!-- Universal Analytics -->
    <script>
        (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
        (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
        m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentBefore(a,m)
        })(window,document,'script','https://www.google-analytics.com/analytics.js','ga');

        ga('create', '<?php echo esc_attr($tracking_id); ?>', 'auto');
        ga('send', 'pageview');
    </script>
    <?php
}
add_action('wp_head', 'add_universal_analytics', 10);

Plugin Solutions

If you prefer using a plugin, here are reliable options:

  1. MonsterInsights - Most popular Google Analytics plugin
  2. Google Site Kit - Official Google plugin for WordPress
  3. GA Google Analytics - Lightweight alternative

Best Practices

  • Always replace the tracking ID placeholder with your actual Google Analytics ID
  • Test tracking implementation using Google Analytics Real-Time reports
  • Consider using a child theme when modifying functions.php
  • For production sites, minify the JavaScript code
  • Consider implementing privacy-related features (like IP anonymization) if needed for GDPR compliance

Remember to get your tracking ID from your Google Analytics account and replace the placeholder in the code before implementation.