Quick answer
If Google Ads tracking broke after Checkout Extensibility, the old script location is probably the first suspect. Additional Scripts, checkout.liquid, and old Thank You page scripts need to be replaced with Shopify’s pixel/customer events model or compatible app pixels.
Symptom
Google Ads, GTM, Microsoft Ads, Meta, affiliate, or analytics purchase tracking worked before the upgrade and stopped firing afterward.
Most likely causes
- Old Additional Scripts no longer run the same way. Shopify’s docs say tracking scripts on old Thank You pages need to be replaced using pixels.
- checkout.liquid is deprecated. Checkout scripts that used to live there need a new home.
- Wrong conversion source. Google Ads may be importing from GA4 while Shopify/app tracking is using another conversion action.
- Customer event sandbox differences. Custom pixels behave differently than raw scripts dropped into the old order status page.
- Enhanced conversions/PII assumptions changed. Shopify’s upgrade docs call out changes around PII access on legacy pages.
Quick checks
- Identify where the old Google Ads/GTM script lived: theme.liquid, checkout.liquid, or Additional Scripts.
- Go to Settings → Customer events and review pixels.
- Confirm whether the Google & YouTube app or a custom pixel is responsible for purchase tracking.
- Place a test order and check whether `checkout_completed` / purchase events fire.
- In Google Ads, confirm the conversion action source and action name match what Shopify is sending.
Theme, app, or code checks
- Do not paste old checkout scripts into theme.liquid and assume they cover checkout completion.
- Review Shopify’s pixel migration guidance.
- If GTM is used, confirm it initializes inside the custom pixel/customer event environment.
- Check browser/ad-blocking and consent behavior before declaring the pixel broken.
- Compare Shopify orders against Google Ads conversions by date after the change.
When to stop guessing
Stop guessing when money reporting is involved. If purchase tracking is not verified after a checkout migration, treat it as a launch blocker.
Prevention checklist
- Keep a tracking map: platform, event, where it fires, owner, test method.
- Before checkout changes, screenshot old Additional Scripts and checkout customizations.
- After migration, run test orders and verify events in ad platforms.
- Do not delete old tracking references until the replacement is confirmed.