How and why can Meta events be duplicated and how do you solve it?
Seeing duplicated events in Meta Events Manager can be confusing, but there are a few common reasons this occurs.
PixelFlow is designed to handle both Pixel and Conversions API events together with deduplication, so in most cases you should not see duplicates. However, misconfiguration or overlapping setups can sometimes cause them.
Common Causes of Duplicate Events
1. Pixel firing alongside CAPI
When events are sent through both the Pixel (browser) and Conversions API (server), Meta expects them to be deduplicated using event IDs. In some cases if you load both separately and don't carefully match the event IDs, Meta will be unable to de-duplicate them effectively.
PixelFlow automatically manages this process, so duplicates from Pixel and CAPI should not happen if you are using PixelFlow correctly.
2. Pixel installed separately on your website
Sometimes a website has the Meta Pixel installed manually in addition to the PixelFlow script.
This leads to the same event being fired twice: once by your standalone Pixel and once by PixelFlow.
Fix: Remove any manually installed Pixel scripts. PixelFlow already loads both the Pixel and Conversions API together, with built-in deduplication.
3. Page reloads and repeated actions
If a visitor reloads a page or takes the same action multiple times in quick succession, events may fire more than once.
Fix: Use PixelFlow’s event blocking rules to prevent the same event from being triggered multiple times in a short time window.
4. Event setup conflicts
An event might be configured in multiple ways. For example:
The same event is assigned to an event URL and triggered manually via a class.
Multiple tracking URLs have been set up for the same event type.
Fix: Review your event setup and ensure each event is only triggered once.
How to Check for Duplicates in PixelFlow
PixelFlow provides an event logs feature where you can see exactly when and how each event was tracked.
By reviewing the logs, you can:
Identify whether an event was triggered from PixelFlow or another source.
Spot duplicate triggers from multiple tracking rules.
Adjust your setup to ensure each event only fires once.
What are the Best Practices to Avoid Duplication of Events?
In summary, as PixelFlow loads both your Meta CAPI and Meta Pixel side by side, server side and browser side events will be automatically deduplicated. Outside of that, these are the best practices to check your setup and avoid duplicate events from incorrect setups:
Only install PixelFlow. Do not add the Pixel separately.
Check your event logs regularly to verify that events are tracking correctly.
Avoid setting up the same event type in multiple ways (using classes and tracking URLs)
Use blocking rules to prevent multiple rapid triggers.
Following these steps will keep your tracking clean and prevent inflated event counts.