Guides

Debugging tracking pixels

Practical answers to the questions that come up when ad and analytics numbers don't add up, based on what pixels actually send from live websites.

• Duplicate purchase events: real duplicates vs. normal repeatsSeveral purchase requests for one order are often normal: several pixels, accounts or request formats. How to find a real duplicate and check the order ID.
• GA4 purchase sent with a value but no currencyA GA4 purchase with a value but no currency: the keys to look for in the request, what Google's reference says about it, and how to check and fix the tag.
• Why one Google Ads hit shows up as several requestsOne Google Ads conversion can leave the browser as conversion, view-through, CCM and GA4-linked requests. What each carries and why it is not a duplicate.
• Why Meta and GA4 report different revenueWhy Meta, GA4 and Google Ads report different revenue for the same orders, and how to see the value, currency and order ID each tag sent in the browser.
• What tracking pixels actually send: a study of 38 websitesWe opened 38 websites with Universal Pixel Debugger and read every tracking request: how many networks fire, where events go, and what is missing.