What is cookie syncing?

Cookie syncing or cookie matching is the process of aligning user data across different ad tech platforms to ensure that all parties can track user interactions consistently. This allows advertisers to recognise users across various sites and devices to deliver more personalized and targeted ads to users across digital advertising channels.

Cookies are domain-specific, meaning the data they collect is accessible only by the parent domain. Cookie syncing enables advertisers, publishers, ad exchanges, demand-side platforms (DSPs), supply-side platforms (SSPs), and data management platforms (DMPs) to share data, allowing them to create a unified user profile.