Since the google and youtube app aready handles GA4 connection including eccomerce data, and google ads also (not sure does it track conversions?)
Facebook Meta app and pixel already does its thing in the app also. We seem to have no need to add any scripts?
What is a concrete use case?
If there is a clear use case, what is the best way to connect to GTM. It seems that in order to run scripts post purchase and on checkout and order thank you apge we need to connect thought a cusotm pixel. Hoever due to the sandboxing, any scripts the run on thoese pages cannot see user DOM interactions so we creat cutom GA4 events to track user actions like custom button clicks etc.
Therefore it seems to me that we need to have hte GTM code block in our theme code, and then in the cutom pixel, have acheck to see if we are on a checkout /thank you/or order dtatsus page and only if we are then initial the GTM custom pixel.
In particular I have this script in the additional scripts section of the checkout admin which is being depracated
{% if first_time_accessed %}
{% endif %}
Quesiton 1: Do I still need to do this or does the google and youtube app already handle conversion tracking?
Question 2: If the answer is that google and youtube app does not handle google ads conversion tracking, and I need to have this script somewhere, is google tag manager using the custom the best way?
If you connect google and youtube app with your shopify store no need to put any extra script for google ads tracking.
Sometimes google and youtube app cannot handle the frequent conversions from google ads. in that case you would need to consider google tag manager by creating a custom datalayer on custom pixel.
Definitely GTM is the best way to configure google ads tracking.
For Shopify stores, Google Tag Manager is mainly used to manage GA4 ,Google Ads conversion tracking, event tracking (like add to cart, checkout, etc.), Meta and TikTok Pixels without editing theme code.
Since GTM allows merchants manage tags and marketing pixels in one place, it becomes valuable for stores which run frequent advertising campaigns. Tracking can be adjusted right in GTM instead of changing Shopify code every time.
Yet, for stores that don’t want a fully manual implementation, there are different GTM apps that simplify GTM integration and data layer setup. Magefan’s Shopify GTM app is one option I’ve seen mentioned for that purpose.
For most stores, the Google and YouTube app already covers the basic GA4 and Google Ads conversion path.
Where GTM still helps is pre-checkout visibility: custom events, third-party tags, debugging what fires on product/cart pages, and controlling tags that the native apps do not cover. The normal theme GTM container should not be treated as your checkout tracking layer, because checkout/thank-you tracking now runs through Shopify’s pixel/app paths and sandboxed Customer Events.
The main mistake is keeping the native apps and GTM both sending purchase events without checking whether they share the same event IDs and parameters. That is where stores end up with either missing purchases or duplicate ones.
