Meta Pixel and Conversions API deduplication on Shopify: event_id explained
Updated · TagGap
Quick answer: If you send purchases from both the browser Pixel and the Conversions API, Meta counts them once only when both carry the same event name and the same event_id. Check Events Manager for deduplication on the Purchase event, and make both senders use the same id, typically derived from the order.
How deduplication works
Meta compares browser and server events from the same dataset. A Purchase from the Pixel and a Purchase from the Conversions API with the same event_id are treated as one event. Without a shared id, Meta may count both, and your purchases and revenue are inflated.
Check it
- In Events Manager, open the Purchase event and review its deduplication and event coverage details for browser and server events.
- Look at a few recent purchases in Test events while placing a test order, and compare the
event_idsent by each source. - Make sure only one Meta Pixel ID is installed for the store. Two pixels mean two datasets, which never deduplicate against each other.
Fix it
- Use one integration that sends both browser and server events with a shared id, or configure both senders to derive
event_idfrom the same order value. - Remove purchase code left in the theme or in old Additional scripts after the move to Shopify’s new Thank you page.
Related fix guides
- Meta browser and server events are not deduplicated
- Meta Conversions API is not covering purchases
- Duplicate purchase events