Event Match Quality (EMQ) is Meta's score for how well the customer information you send with an event can be matched to a Meta user. Higher EMQ means more conversions attributed and a stronger signal for optimization.
Why matching decides measurement
When your pixel or Conversions API fires an event, Meta tries to match it to a user using the parameters you pass, email, phone, name, IP, and more. The more clean, hashed parameters you send, the higher the EMQ and the more events Meta can attribute.
How to raise it
Send more customer-information parameters (hashed), deploy the Conversions API alongside the pixel with deduplication, and keep the data clean. Low EMQ is a quiet cause of under-reported conversions and weaker delivery, the Meta equivalent of the measurement gaps that mislead attribution.