If Ads Manager reports fewer sales than your store, browser tracking is the culprit. Here's how CAPI fixes it.
Why pixels undercount
The Meta Pixel runs in the browser, which means iOS privacy prompts, Safari's tracking prevention and ad blockers can all stop it from firing. Depending on your audience, 20–40% of real conversions never reach Meta — so the algorithm optimizes on incomplete data and your reported ROAS looks worse than reality.
What the Conversion API does
The Conversion API (CAPI) sends the same events from your server directly to Meta, bypassing the browser entirely. When a purchase happens, your store's backend reports it — no ad blocker can interfere. Paired with the pixel, CAPI fills the gaps browser tracking leaves behind.
Deduplication: the part most setups get wrong
Running Pixel and CAPI together means Meta may receive the same event twice. Correct implementations attach a shared event ID to both, letting Meta deduplicate automatically. Setups without deduplication double-count conversions — which is worse than undercounting, because it trains the algorithm on false wins.
How to verify your setup
In Events Manager, check that purchase events show 'Deduplicated' across browser and server channels, and review your Event Match Quality score — aim for 6.0 or higher on purchases. If either fails, the setup needs professional attention before you scale spend.
- #Meta Ads
- #CAPI
- #Tracking
AppDeel Editorial Team
Web Development & SEO Specialists
We build and grow websites for clients worldwide. Everything we publish comes from patterns tested on real projects.