HubSpot Tracking & B2B Funnel Integration GTM, GA4, and Google Ads Server-Side Tracking in 2026

				
					<script>
(function() {
  // Listen for message events emitted by embedded HubSpot forms
  window.addEventListener("message", function(event) {
    // Validate that the message comes from HubSpot
    if (event.data && event.data.type === "hsFormCallback" && event.data.eventName === "onFormSubmitted") {
      
      var formData = event.data.data;
      var submissionData = formData.submissionValues || {};
      
      // Extract client-side parameters and cookies
      var gclid = getParam('gclid') || getCookie('gclid');
      var hubspotutk = getCookie('hubspotutk');
      
      // Push normalized payload into the Data Layer
      window.dataLayer.push({
        'event': 'hubspot_form_success',
        'form_id': formData.formId,
        'user_data': {
          'email': submissionData.email || '',
          'firstname': submissionData.firstname || '',
          'lastname': submissionData.lastname || '',
          'phone': submissionData.phone || '',
          'company': submissionData.company || ''
        },
        'tracking_identifiers': {
          'gclid': gclid,
          'hubspotutk': hubspotutk
        }
      });
    }
  });

  // Helper function to parse URL parameters
  function getParam(param) {
    var match = RegExp('[?&]' + param + '=([^&]*)').exec(window.location.search);
    return match && decodeURIComponent(match[1].replace(/\+/g, ' '));
  }

  // Helper function to parse cookies
  function getCookie(name) {
    var value = "; " + document.cookie;
    var parts = value.split("; " + name + "=");
    if (parts.length === 2) return parts.pop().split(';').shift();
  }
})();
</script>