Meta Pixel and Conversions API Deduplication Issues on Shopify

Topic summary

A Shopify store owner integrated Meta Pixel via Meta’s official app in December 2024 without issues, but recently received deduplication errors from Meta.

Core Problem:
Meta is flagging that Purchase, AddPaymentInfo, InitiateCheckout, and Search events are being sent from both the Pixel and Conversions API without proper deduplication, potentially causing over-reporting of conversions.

Technical Issue:
The error indicates missing event_id parameters that are required to deduplicate identical events sent through both tracking methods. Additionally, there’s a separate issue with unmatched content IDs.

Current Status:
The user understands that adding event_id parameters to both Pixel and Conversions API events is necessary but is uncertain about implementation steps within their Shopify setup. They’re seeking detailed guidance on how to properly configure these parameters to resolve the deduplication errors.

Three diagnostic screenshots are included showing the specific error messages from Meta’s interface. No responses or solutions have been provided yet.

Summarized with AI on October 30. AI used: claude-sonnet-4-5-20250929.

Hello Shopify Community,

In December 2024, I integrated Meta Pixel with my Shopify store using Meta’s official app, and everything functioned smoothly. I have not made any special or unusual changes to my Shopify setup. However, this afternoon, I received the following error message:

“Your pixel is receiving identical Purchase events from your pixel code and the Conversions API, but they are not deduplicated correctly. This may cause over-reporting of conversions, as your ad set is optimizing for Purchase events.”

In the Diagnostics section, I encountered these specific errors:​

  • Purchase Event Missing Deduplication Parameter​
  • AddPaymentInfo Event Missing Deduplication Parameter​
  • InitiateCheckout Event Missing Deduplication Parameter​
  • Search Event Missing Deduplication Parameter​
  • Web - Fix unmatched content IDs

​After conducting thorough research, I understand that adding an event_id parameter to both the pixel and Conversions API events is crucial for proper deduplication. However, I’m uncertain about the exact steps to implement this in my Shopify setup.

Could anyone provide detailed guidance or best practices on how to add the event_id parameter to ensure accurate event tracking and resolve these deduplication errors?

Thank you in advance for your assistance!