What is Google Ad Manager?
Google Ad Manager is Google's platform for publishers to manage and sell their ad inventory. It combines a publisher ad server (formerly DoubleClick for Publishers, or DFP) with Google's ad exchange (AdX), handling direct deals, programmatic auctions and reporting. It is the most widely used publisher ad stack and is at the center of US and EU antitrust cases.
Google bought DoubleClick in 2008 and merged DFP and AdX into Google Ad Manager in 2018. Through it, publishers access demand from Google Ads and Display & Video 360 as well as other buyers. Features such as dynamic allocation and last look historically gave AdX advantages over rival exchanges, which regulators called self-preferencing.
The EU fined Google €2.95 billion in September 2025 over these practices, and in the US, Judge Brinkema's September 2026 remedies ruling required Google to open Ad Manager to rivals, including Prebid integration and fair treatment of rival ad servers, overseen by a monitor, without forcing a sale of AdX.