Why this won’t match GA4 — and which number to trust. These two sections measure conversion in fundamentally different ways, so they will never agree:
• Denominator: Meta counts landing-page views (ad clicks that actually loaded the site); GA4 counts sessions.
• Attribution: Meta credits itself for any purchase inside its 7-day-click / 1-day-view window — even when the final visit came from email, branded search or direct. GA4 only credits Meta when the converting session was last-clicked from Meta.

Net effect: Meta over-credits itself; GA4 under-credits Meta. That is why Meta-reported CVR (~4.5%) sits above GA4’s Meta cut (~1.4%) — higher, not lower. Neither is “the” number; the truth is in between. Use Meta here to judge FB-vs-IG relative performance, and the GA4 / Shopify views for absolute site conversion.

On the FB+IG line: FB and IG CVR are both drifting down through 2026, and IG has fallen faster (~5% in late-2024 to ~3% by mid-2026). The blended line is a volume-weighted average, so it rides below FB and is pulled toward IG as IG’s share grows — making the combined chart look like the steepest drop even though it is just the two trends merging. The plunge in the final bar is June being a partial, still-reporting month — ignore the last point until the month closes.

Traffic Trends