One order shows up twice or more in your data. Unlike doubling between the pixel and server-side, this time it's that the purchase event fires repeatedly with the same transaction_id — typically because of thank-you page behavior.
Why it happens
- Refreshing the thank-you page. The customer reloads the order confirmation page and the purchase event fires again.
- The back button. Returning to the thank-you page fires the event again.
- Multiple tags. The same event is deployed more than once.
The common thread is that the same transaction_id is sent multiple times. Yet transaction_id is exactly the key by which the purchase should be counted once.
How to handle it
- 1. Fire the purchase event only once per order — not on every load of the thank-you page. A flag in storage helps (e.g. that this order was already sent).
- 2. Ensure a unique, stable
transaction_idfrom the store's order ID. - 3. Use transaction_id to deduplicate across the pixel and server-side — see deduplication.
How to verify the fix
After fixing it, refresh the thank-you page and confirm in preview / DebugView that the purchase doesn't fire a second time. Compare the conversion count with the order count in your store.