DEV Community

Montherion Labs
Montherion Labs

Posted on Originally published at tracklint.netlify.app

How to check Meta Pixel event parameters in the browser

#googleanalytics #analytics #webdev #abotwrotethis

The Meta Pixel uses standard events to measure conversions and build audiences. Inspecting their parameters in the browser helps you check the values, currencies, and product data sent by the browser before relying on the Events Manager.

How to see Meta Pixel requests

  1. Open DevTools (F12), go to the Network tab and type facebook.com/tr in the filter.
  2. Trigger a standard event on your site, such as adding a product to the cart or completing a purchase.
  3. Select the request and look at the Payload tab. Meta Pixel parameters are often encoded as cd[...] fields in the query string or form body.

Key parameters to check

Meta’s documentation defines specific parameters for standard events:

  • ev: the event name, such as Purchase or AddToCart.
  • cd[value]: the monetary value as a decimal number (e.g., 9.99), without currency symbols.
  • cd[currency]: a three-letter ISO 4217 code like USD or EUR.
  • cd[content_ids]: a JSON array of product IDs. cd[contents]: a JSON array of objects with id and quantity, optionally item_price.
  • cd[num_items]: the quantity of items.

Purchase requires value and currency.

Deduplication with the Conversions API

If you send the same events from the browser and a server (Conversions API), Meta needs to deduplicate them so they only count once.

  • Look for the eid (Event ID) parameter in the browser request.
  • For ID-based deduplication, send the Pixel eventID (serialized as eid) as the Conversions API event_id, with the same event name and pixel/dataset, within Meta’s deduplication window. Use a different ID for each distinct event. The browser alone cannot confirm server delivery or deduplication.
  • Standard events sent multiple times from the browser with identical data without an Event ID can inflate your conversion metrics.

Scope

These checks examine outgoing requests visible in the browser. They do not establish what Google Analytics or Meta received, processed or counted, and they do not inspect server-to-server traffic or determine legal compliance.

Google Analytics and Google Tag Manager are trademarks of Google LLC. Meta is a trademark of Meta Platforms, Inc. Tracklint is not affiliated with, endorsed or sponsored by Google or Meta.

This article was written with AI assistance (#ABotWroteThis). It was first published on the Tracklint website: How to check Meta Pixel event parameters in the browser.

Top comments (0)