Pixel-to-Conversion Discrepancy

Definition

Pixel-to-Conversion Discrepancy: The pixel-to-conversion discrepancy is the gap between orders reported by your storefront (Shopify, WooCommerce, etc.) and conversions reported by your Meta or Google pixel for the same time window. A gap over 15% signals broken tracking.

# Pixel-to-Conversion Discrepancy The pixel-to-conversion discrepancy (pixel CVD gap) compares the ground truth — actual orders in your storefront — to the conversions Meta and Google report from their pixel for the same period. A discrepancy of 5-10% is normal (view-through windows, cross-device, lookback overlap). A discrepancy above 15% signals that a significant share of purchases is either unmatched or over-attributed. ## Why it matters You cannot trust a platform-reported ROAS when the pixel is missing 1 in 5 purchases. Even worse, you cannot trust it when the pixel is claiming 1.3 purchases for every real order (common when a Thank You page is misconfigured and a Purchase event fires twice). The pixel CVD gap is your circuit breaker. ## How Admaxxer surfaces it Admaxxer reconciles storefront orders against Meta + Google pixel-reported conversions daily, with a red banner when the gap exceeds 15% and a per-event breakdown showing which event (Purchase, Subscribe) is drifting. Paired with [CAPI match rate](/glossary/capi-match-rate), it gives you a two-number diagnosis: is the pixel firing? is Meta matching what I send? ## Example If Shopify reported 1,200 orders last week and Meta reported 950, your pixel CVD gap is -21% (Meta is under-reporting). The two most common causes: Purchase events not firing on the Thank You page (fix: add pixel server-side), or iOS 14.5 signal loss (fix: raise [CAPI match rate](/glossary/capi-match-rate)).

Most related

Continue exploring the DTC ad-analytics vocabulary — every term in this glossary cross-links to the next.

Frequently Asked Questions

What is a normal pixel-to-conversion discrepancy?

5-10% in either direction is typical. Above 15% is a signal to investigate; above 25% usually means a broken install or a duplicated Thank You page.

Why does my pixel report more conversions than Shopify?

Usually duplicate Purchase events — the pixel fires on Thank You page reload, back-button navigation, or on a checkout step that is not an actual purchase. Deduplicate with event_id.

Can CAPI close the gap?

Yes, partially. Server-side events catch purchases where the browser pixel failed (ad blockers, Safari ITP). Pairing pixel + CAPI usually closes 50-70% of the iOS 14.5 gap.

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