Event deduplication

How event_id keeps browser and server events from being counted twice, and how to check it.

Why send an event twice?

The browser pixel loses events (ad blockers, Safari, iOS, slow pages); the server misses browser context. Sending both gives Meta the best of each — but only if Meta knows they are the same event.

How Meta deduplicates

Meta merges a browser event and a server event when they have the same event name and the same event ID (eventID in the pixel, event_id in the Conversions API), received within 48 hours. The first one wins; the second is dropped as a duplicate.

What TrackPilot does for you

• The script wraps fbq: each call gets an ID and our server copy uses the same one.
• Purchase with an order_id gets purchase_<order_id> — the ID the WordPress plugin and your server use too.
• Your own eventID is always respected.

How to check

1. Dedup checker in your dashboard: events seen from browser, server, or both with the same ID.
2. Events Manager → your pixel → Overview → event → "Event deduplication" / "Connection method: Browser · Server".

Common mistake: another plugin (or a GTM tag) also sends Conversions API events with its own random IDs. Turn one of them off.

Stuck? Ask for setup help — we answer in বাংলা or English.