It's one of the most common questions in performance marketing: why doesn't GA4 match Meta? The short answer is that they were never designed to. The longer answer is what separates a normal gap from a real problem.
Different attribution models
Meta credits conversions to ad interactions using its own view-through and click-through logic. GA4 uses a last-click or data-driven model across all channels. They are answering different questions, so they produce different numbers.
Different attribution windows
Meta may attribute a conversion to a click that happened days earlier. GA4's session and attribution logic may assign that same conversion to a different source entirely. Neither is 'wrong', they're measuring different things.
Where the gap becomes a red flag
A normal gap is stable and explainable. A problem looks different:
- GA4 recording far fewer conversions than actually happened
- Events missing entirely from GA4 that Meta clearly captured
- Sudden shifts after a website, GTM, or consent change
- Conversion values that don't match between the two
How to fix it
Start by confirming your GA4 events and Meta events fire on the same actions with the same values. Then reconcile the attribution settings so you're comparing like with like. A GA4 and pixel review, or a full measurement audit, will surface the misconfigurations behind an abnormal gap.
Related reading: our services and the Measurement Health Audit.
Think this might be happening in your account?
A Measurement Health Audit traces every conversion end to end and tells you exactly what's duplicated, missing, misfiring, or misaligned.