Why is GA4 showing (direct) / none for my Shopify checkout sales?

When users navigate from WordPress to a separate Shopify domain checkout, GA4 loses client ID cookies and generates a brand-new session. GA4 Linker fixes this by automatically appending the _gl parameter to cross-domain links.

Does GA4 Linker support slide-out AJAX carts and popup checkout buttons?

Yes! The Pro and Agency plans use a high-performance MutationObserver that detects dynamically injected DOM elements and AJAX cart drawers in real-time.

Is coding required to set up GA4 Linker?

Zero coding required. Simply install the plugin, enter your Shopify checkout domain(s) in the WordPress admin panel, and GA4 Linker handles link and form decoration automatically.

How does GA4 Linker preserve UTM parameters?

On Personal, Pro, and Agency plans, GA4 Linker captures incoming utm_source, utm_campaign, utm_medium, and gclid parameters from your landing page and persists them through internal navigation directly into the Shopify checkout destination.

🛠️ Testing & Diagnostics

How to Test if Your GA4 _gl Cross-Domain Token is Working Correctly

By Dimsquid Engineering•Published Aug 5, 2026•8 min read

Once you have configured cross-domain tracking between your WordPress site and your Shopify checkout, you must verify that Google Analytics 4 is successfully passing session tokens. Here are the 3 reliable methods to test your _gl cross-domain setup in Chrome DevTools and GA4 DebugView.

Method 1: Inspect the Destination Checkout URL

Open an Incognito browser window, visit your WordPress landing page with test parameters (yourbrand.com/?utm_source=test), and click your "Buy Now" button. Inspect the destination URL on Shopify:

Valid Decorated URL Structure:

https://checkout.myshopify.com/cart/123?_gl=1*1a2b3c*_ga*MTIzNDU2Nzg5LjE2NzAwMDAwMDA.*_ga_F1TNRJQML7*R1MxLjEu...

If the _gl query parameter is present and starts with 1*..., GA4 has successfully appended the encrypted session token.

Method 2: Compare Client IDs in Chrome DevTools Application Tab

Open Chrome DevTools (F12) and navigate to Application ➔ Cookies:

Check the value of the _ga cookie on yourbrand.com (e.g., GA1.1.987654321.1670000000).
Click to Shopify checkout and inspect the _ga cookie on checkout.myshopify.com.

✅ Success Condition: Both cookie values match perfectly across domain boundaries!

⚡ Automated Diagnostic

Method 3: GA4 Linker Attribution Health Scanner

Instead of inspecting cookies manually, GA4 Linker includes a live diagnostic scanner inside WordPress Admin Settings that checks active _ga, _fbp, and target domains in real-time.

Get GA4 Linker Plugin Free →