What Is Header Bidding?

Header bidding is a programmatic advertising method that allows publishers to run a real-time auction for ad inventory among multiple demand partners simultaneously, before calling their ad server. Instead of using the older “waterfall” approach, where impressions trickled down from one buyer to the next, header bidding lets all buyers compete at once.

This process increases competition, drives higher CPMs, and provides publishers with greater transparency into the true value of their impressions. Advertisers also benefit by gaining access to premium inventory that was once only available through direct deals.

How Header Bidding Works

• A snippet of JavaScript in the website’s header requests bids from multiple demand partners.

• Each partner runs its own mini-auction and returns the top bid.

• The publisher’s ad server compares those bids and serves the winning ad.

All of this happens in milliseconds, ensuring the page loads quickly while maximizing yield.