This kind of tracking mismatch between Facebook Ads and Shopify is common and usually comes down to how each platform attributes conversions.
Attribution Window Differences
- Facebook may count purchases that happened within 7 days of an ad click or 1 day of an ad view—even if the user didn't convert right away.
- Shopify only tracks direct, last-click conversions, so it reports fewer.
Duplicate Events from Pixel & CAPI
If you’re using both the Facebook Pixel and Conversions API (CAPI) without proper deduplication, Facebook may be counting the same purchase twice.
Cross-Device Attribution
Facebook can credit a sale if someone clicked an ad on mobile but bought later on desktop. Shopify won’t connect the two unless the session carries over.
How to Fix or Align Tracking
- Check for event deduplication in Facebook Events Manager → Make sure purchase events have unique event_ids.
- Review attribution settings in Facebook → Consider changing to 1-day click for a closer match with Shopify.
- Use UTM tracking in your ads to confirm which traffic converts in Shopify’s analytics.
- Verify Shopify’s Facebook integration is properly set up (in Settings → Sales Channels → Facebook & Marketing).
