Meta Pixel vs Conversions API: understanding deduplication
The Pixel and the Conversions API measure the same actions through two different paths. Using them together improves coverage, provided Meta knows they are the same events.
Published 12 October 2026 · Updated 12 October 2026 · 5 min read
The Meta Pixel sends events from the browser; the Conversions API sends them from the server. By sending the same event through both channels with the same event_name and event_id, Meta deduplicates it and counts it once, while still covering cases where the browser blocks the Pixel.
The Pixel: simple, but dependent on the browser
The Meta Pixel is a script that runs in the visitor’s browser. It records events (page view, content viewed, checkout started, purchase) and sends them to Meta. It’s easy to install and rich in browser signals.
Its limit is structural: anything that prevents the script from running or sending loses the event. Ad blockers, browser protections, declined consent, a dropped connection or a tab closed too early are examples.
The Conversions API: sending from the server
With the Conversions API, your server sends the event to Meta through a direct request. It doesn’t depend on the visitor’s browser, and it can replay a failed send.
It doesn’t see everything the browser sees, though: click and browser identifiers (such as fbp and fbc) must be passed along so Meta can match the event to the right person.
Quick comparison
| Criterion | Pixel (browser) | Conversions API (server) |
|---|---|---|
| Where does it run? | In the visitor’s browser | On your server |
| Affected by blockers? | Yes | No, since it doesn’t go through the browser |
| Can a failed send be replayed? | With difficulty | Yes, with a queue |
| Browser signals | Directly available | Must be passed along (fbp, fbc, IP address, user agent) |
| Recommended use | Together with the Conversions API | Together with the Pixel |
Deduplication: same name, same identifier
If you send a purchase through the Pixel and the same purchase through the API, Meta could count it twice. To avoid this, both copies must carry:
- the same event name (event_name), for example Purchase
- the same event identifier (event_id), generated once and reused by both channels
- consistent data (value, currency, contents)
What about a retry?
A failed send must be replayed without becoming a new event. Best practice is to keep the original event_id and timestamp on retries: Meta then recognizes the same event. That’s what ReadyStore does for its server sends.
Verify in Events Manager
- 1
Open the data source
Select your Pixel in Meta Events Manager.
- 2
Compare the channels
Check that each important event is received from both the browser and the server.
- 3
Verify deduplication
Make sure duplicates are discarded and volumes aren’t doubled.
Frequently asked questions
Do I have to choose between the Pixel and the Conversions API?
No: using them together, with deduplication, is generally the most complete setup.
What happens if the event_id differs between channels?
Meta may count the event twice, because it can’t recognize that it’s the same one.
Does ReadyStore handle deduplication?
Yes: events are sent by the browser and by the server with the same event_name and event_id, and retries keep the original event_id.
Keep exploring
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Learn more
Set up the dual channel on your store.
Create your store, add your Pixel and verify deduplication in Meta.