event_id generator for Pixel + server deduplication
Meta deduplicates a browser Pixel event and a Conversions API event when the Pixel's eventID matches the server event_id and the event names match (Meta: Handling duplicate Pixel and Conversions API events). The safest ID is built from the record that caused the conversion, so retries reuse it. This tool builds one and gives you matching snippets.
event_id: Meta event_name:
Browser (Meta Pixel)
Server (server-track-lab)
Full explanation: Meta CAPI deduplication with event_id. Check the payload: CAPI payload validator · send a dry-run event in the playground.
POST /api/v1/track call: we normalize, hash, dedupe on event_id and forward to Meta CAPI. Free for 1,000 events a month, then CA$2 per 1,000. Get a free API key · Try the playground · API docsFAQ
What makes an event_id deterministic?
It is derived only from things that don't change: the event name and the ID of the record that caused it (a booking, signup or deal). Retrying the same conversion produces the same event_id, so it is deduplicated instead of double counted.
Does the Pixel event name need to match too?
Yes. Meta's deduplication docs say both the event ID and the event name must match. This tool shows the Meta event name server-track-lab maps your event to, and uses it in the fbq snippet.
How long does Meta deduplicate for?
Meta's documentation says events are only deduplicated if received within 48 hours of the first event with that event_id. server-track-lab also ignores repeats of the same event_id in your workspace for 72 hours.
Is anything sent to a server?
No. IDs and snippets are generated in your browser; the optional hashed form uses WebCrypto locally.