The Problem

When users navigate from website.com to portal.website.com, GA4 and Adobe Analytics treat them as:

The Solution

Our universal CrossDomainLinker handles everything automatically:

Quick Start

// 1. Add script to your site
<script src="CrossDomainLinker.js"></script>

// 2. Initialize with your domains
<script>
  const linker = new CrossDomainLinker({
    domains: {{DOMAINS_ARRAY}}
  });
</script>

// That's it! Cross-domain tracking is now active.

Using Adobe?

Adobe Analytics uses Visitor ID Service for cross-domain tracking (not a linker). Add your Report Suite ID and Tracking Server in the Project panel, then open Snippet Library and filter by adobe for the Visitor ID snippet and other Adobe configs.

Tag communication & taxonomy

How measurement tags communicate across domains, within the page, and across campaigns — and how a consistent event/parameter taxonomy keeps implementations aligned.

Domain list validator

Paste your domains (one per line). We’ll validate format and show which will be linked and any subdomain notes.

Method 1: Direct Implementation

Add the script directly to your website's HTML. This method works great for sites with full code access.

<!-- Add before closing </head> tag -->
<script src="/path/to/CrossDomainLinker.js"></script>
<script>
  window.crossDomainLinker = new CrossDomainLinker({
    domains: {{DOMAINS_ARRAY}},
    measurementId: '{{MEASUREMENT_ID}}',
    debug: false
  });
</script>

Method 2: Google Tag Manager

Recommended for most implementations. Easier to manage and doesn't require code changes.

Step 1: Create Variables

// Variable Type: Custom JavaScript
// Variable Name: CrossDomain - Domain List

function() {
  return [
{{DOMAINS_ARRAY_LINES}}
  ];
}

Step 2: Create Custom HTML Tag

<script>
{{CrossDomainLinker Script}}

window.crossDomainLinker = new CrossDomainLinker({
  domains: {{DOMAINS_ARRAY}},
  measurementId: '{{MEASUREMENT_ID}}',
  debug: false,

  onDecorate: function(data) {
    dataLayer.push({
      event: 'cross_domain_decorated',
      cd_type: data.type,
      cd_target: data.url.hostname
    });
  },

  onError: function(error) {
    dataLayer.push({
      event: 'cross_domain_error',
      error_type: error.type
    });
  }
});
</script>

Step 3: Configure Trigger

Method 3: WordPress Plugin

For WordPress sites, add via theme's functions.php or a custom plugin.

function enqueue_cross_domain_linker() {
  wp_enqueue_script(
    'cross-domain-linker',
    get_template_directory_uri() . '/js/CrossDomainLinker.js',
    array(),
    '2.0',
    false
  );

  wp_add_inline_script('cross-domain-linker', "
    window.crossDomainLinker = new CrossDomainLinker({
      domains: {{DOMAINS_ARRAY}},
      measurementId: '{{MEASUREMENT_ID}}'
    });
  ");
}
add_action('wp_enqueue_scripts', 'enqueue_cross_domain_linker');

Method 4: Adobe Launch (Data Collection)

For Adobe Analytics, use Launch to deploy tracking. Add your Report Suite ID and Launch Property ID in the Project panel, then open Snippet Library and filter by adobe for the Launch embed, Visitor ID (cross-domain), and Analytics config snippets.

Configuration Options Reference

Adobe configs

Adobe Analytics, Launch, and Visitor ID configs use different patterns (AppMeasurement s object, Launch embed, Visitor API). Add Report Suite ID and Tracking Server in Project, then open Snippet Library and filter by adobe for ready-to-copy snippets.