Prebid Header Bidding With Google Ad Manager: A Practical Introduction

Header bidding lets several demand partners bid on an impression at the same time, before your ad server decides what to show. Prebid is the open-source project most publishers use to do it.

How it works with Ad Manager

The page loads and Prebid.js sends bid requests to your chosen bidders in parallel. Bids come back within a timeout you set. Prebid then passes the best bids to Google Ad Manager as key-values, using the kind of price-priority line items Google documents. Ad Manager runs its own decision, where AdX and other line items compete with the Prebid bids, and the winning ad renders.

The key point is that Ad Manager stays the final decision maker. Prebid adds competition; it doesn't replace your ad server.

Why Prebid

According to Prebid.org's introduction to the project, the software is free and open source under the Apache license, and the organization takes no cut of winning bids. You can choose your own bidder adapters and change them whenever you want.

What you need to start

• A Google Ad Manager network with ad units and placements
• Accounts with two to five demand partners (SSPs) that have Prebid adapters
• Price-priority line items in Ad Manager keyed to Prebid price buckets
• A consent management platform if you have users in regions that require one
• ads.txt lines for every new partner

Settings that matter

Timeout length is the first trade-off: longer timeouts collect more bids but delay ads, so it's worth starting conservative and testing from there. Price granularity is the second: finer buckets capture bids more accurately but need more line items. The number of bidders matters too, though more isn't always better, since each one adds a network request and the ones that rarely win are worth dropping. Lazy loading helps as well, by requesting bids only for ad slots close to the viewport to protect page speed.

Header bidding and Open Bidding

Google also offers Open Bidding, where invited third-party exchanges compete inside Ad Manager's server-side auction. Many publishers run both: Prebid for partners not in Open Bidding, and Open Bidding for the rest. Google's unified pricing rules set floors across these channels.

The H&T GAMING approach

H&T GAMING's header bidding solutions page reports that its setup uses Prebid.js v11 or later, supports client-side and server-side bidding, and connects to 15+ SSP partners. As an AdX partner, it combines that demand with Google's exchange.

If you're weighing whether header bidding would move the needle on your site, a free account review can show how your current demand stack is performing today, and you can request one here.