Common reasons add-to-cart tracking doesn’t fire
- GTM container not published - You imported the container but didn’t click Submit → Publish.
- GTM snippet not installed on your site - The GTM code needs to be in your site’s <head> and <body>.
- AJAX add-to-cart doesn’t trigger a page load - Most modern stores add items to the cart via AJAX. A Page View trigger won’t fire. You need a Custom Event or DOM listener that detects the AJAX request.
- Button selector changed after theme update - Theme updates often rename CSS classes. If your trigger targets
.add-to-cart-btnand the new theme uses.product-add-btn, the trigger silently breaks. - Product data not extractable from DOM - Your tag needs product name, price, and ID. If these aren’t in the dataLayer or in predictable DOM elements, the tag fires but sends incomplete data.
Step-by-step debugging checklist
- Verify GTM is installed - Visit your site, right-click → View Page Source, search for “GTM-”. If you don’t see it, GTM isn’t installed.
- Check GTM Preview mode - In GTM, click Preview. Navigate your site and trigger the event. Look for your tag in the Tags Fired section.
- Check the trigger - If the tag shows as “Not Fired”, click on it to see which trigger conditions aren’t met.
- Click the add-to-cart button with GTM Preview open - Check if any event fires at all. If you see nothing, the click isn’t reaching GTM (likely AJAX). If a Click event fires but your tag doesn’t, your trigger conditions are wrong.
- Inspect the network tab - Open DevTools → Network, click add to cart, and look for an AJAX request to a cart endpoint (e.g.,
/cart/addon Shopify,?wc-ajax=add_to_carton WooCommerce). This confirms the add-to-cart mechanism.
Squarespace-specific issues
Squarespace’s add-to-cart button triggers an AJAX request. The button typically has the class .sqs-add-to-cart-button. You can use a Click trigger targeting this class, but note that the click fires before the item is actually added. To confirm the item was added successfully, you’d need to monitor the AJAX response.
How to verify it’s working
- Open GTM Preview/Debug mode
- Navigate to your site
- Trigger the event (click add to cart)
- Check the GTM debug panel - your tag should appear under “Tags Fired”
- Check GA4 DebugView (GA4 → Admin → DebugView) to confirm the event arrived
Still didn’t work?
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