Differences between client-side and server-side header bidding (PSP)


The main difference lies in where the advertising space auction takes place.
Client-side header bidding is executed in the user’s browser. The header bidding code is placed in the website’s header and loads when the page is accessed. It provides transparency and eliminates the need for cookie syncing.
However, an excessive number of connected SSPs can overload the browser and the user’s device, potentially slowing down navigation and negatively impacting the user experience.

In server-side header bidding, the auction takes place on the publisher’s server, which optimizes potential latency issues. However, there needs to be cookie syncing, which can penalize this working method.

Combining both types of header bidding is possible, allowing the advantages of each to be leveraged.

The most commonly used client-side header bidding is Prebid. Currently, many players offer server-to-server solutions, including Xandr, Magnite, Pubmatic, Index, and Amazon, among others.