Prebid.js

De facto open-source standard for header bidding, used by thousands of publishers globally with the largest ecosystem of demand partner adapters in the industry

Prebid.js is the world's most widely adopted open-source header bidding solution, maintained by Prebid.org — a consortium-style organization governed by industry stakeholders including major publishers, SSPs, and technology companies. Originally created by AppNexus in 2015 and later open-sourced, Prebid.js allows web publishers to run simultaneous auctions among multiple demand partners before making a final ad server call, dramatically improving yield compared to traditional waterfall monetization. The project is stewarded by Prebid.org, a non-profit trade organization that oversees governance, roadmap, and community contributions. The Prebid ecosystem has expanded well beyond its original JavaScript library to include Prebid Server (a server-side header bidding solution), Prebid Mobile (for iOS and Android apps), and Prebid Video. With hundreds of demand partner adapters and a massive global community of contributors, Prebid.js has become the de facto standard for header bidding implementation, used by thousands of publishers ranging from small independent sites to major media companies. Its open-source nature ensures neutrality, transparency, and continuous innovation driven by the broader industry. In the AdTech ecosystem, Prebid.org occupies a uniquely influential position as a neutral, community-governed infrastructure layer. It competes indirectly with proprietary header bidding wrappers offered by companies like Google (Open Bidding), Amazon (TAM), and Index Exchange, but its open-source model and vendor-agnostic approach have made it the preferred choice for publishers seeking control and flexibility. The organization is supported by membership fees from commercial participants and volunteer contributions from the broader AdTech community.