OpenRTB Consortium

Sole author and maintainer of the universal real-time bidding protocol standard used across the global programmatic advertising industry

The OpenRTB Consortium, now stewarded by the IAB Tech Lab, is the industry body responsible for developing and maintaining the OpenRTB protocol — the foundational technical standard that enables real-time bidding (RTB) in programmatic advertising. Originally launched in 2010 as a collaboration between leading demand-side platforms (DSPs) and supply-side platforms (SSPs), the consortium established a common language for bid requests and responses, dramatically reducing integration complexity across the ecosystem. The protocol has become the universal backbone of programmatic advertising, with virtually every major ad exchange, DSP, SSP, and publisher technology platform implementing it. The OpenRTB specification defines how ad exchanges and supply sources communicate with bidders in real time, standardizing fields for inventory attributes, user data, targeting parameters, and bid responses. Over successive versions — from OpenRTB 2.x through OpenRTB 3.0 — the protocol has evolved to address new ad formats (video, native, audio, CTV), privacy requirements, supply chain transparency (ads.txt, sellers.json, SupplyChain object), and fraud prevention. OpenRTB 3.0 introduced a more modular, layered architecture to improve flexibility and security. As part of the IAB Tech Lab, the OpenRTB working group operates as an open, member-driven standards body rather than a commercial entity. Its significance in the AdTech ecosystem cannot be overstated — it is the lingua franca of programmatic advertising, enabling hundreds of billions of ad auctions daily across the open web, mobile apps, connected TV, and digital out-of-home environments. Participation in the working group is open to IAB Tech Lab members, including publishers, agencies, ad tech vendors, and brands.