Real-time Bidding (RTB) is a way transacting media that allows an individual ad impression to be put up for bid in real-time. This is done through a programmatic on-the-spot auction, which is similar to how financial markets operate. RTB allows for Addressable Advertising; the ability to serve ads to consumers directly based on their demographic, psychographic, or behavioral attributes.
The Real-Time Bidding (RTB) Project, formerly known as the OpenRTB Consortium, assembled by technology leaders from both the Supply and Demand sides in November 2010 to develop a new API specification for companies interested in an open protocol for the automated trading of digital media across a broader range of platforms, devices, and advertising solutions. At the time Programmatic had only accounted for 4% of the display advertising market. By 2017, RTB is expected to account for 29% of the digital mix. *Source: eMarketer March 2013. This group continues to create open industry standards that ensure all parties, buy and sell side alike, can transact RTB at scale and build future industry innovation.
The following table provides links to previous version of OpenRTB.
| Version | Release Date |
| OpenRTB v2.6-202309 Features include:
| September 2023 |
| OpenRTB v2.6-202303 Features include:
| April 2023 |
| OpenRTB v2.6-202211 Features include:
| November 2022 |
| OpenRTB 2.6 (PDF) OpenRTB 2.6 includes features to support CTV buying and selling. Release highlights include:
| April 2022 |
| OpenRTB 3.0 (PDF) OpenRTB 3.0 includes features to give buyers more transparency during the bid process. Release highlights include:
| September 2017 |
| OpenRTB 2.5 (PDF) OpenRTB 2.5 included updates that integrated industry trends and allowed for improvements in programmatic technology. Release highlights include:
| December 2016 |
| OpenRTB 2.4 (PDF) OpenRTB 2.4 main improvements:
| March 2016 |
| OpenRTB 2.3.1 (PDF) Provided an update to the specification addressing two typos:
| June 2015 |
| OpenRTB 2.3(PDF) The OpenRTB 2.3 specification was the first version updated to provide support for native ads. This was one of the most significant updates to OpenRTB as it allows for native ads to be targeted, optimized, and transacted on programmatically, reducing workload on publishers and advertisers alike. Release highlights include:
| January 2015 |
| OpenRTB 2.2(PDF) OpenRTB 2.2 provided for improved PMP and non-intentional traffic support. With bot traffic becoming an increasing concern to both the buy and sell sides, OpenRTB 2.2 allows for all parties to be able to provide real-time feedback on ads to determine and block non-human traffic. Release highlights include:
| April 2014 |
| OpenRTB 2.1 (PDF) OpenRTB 2.1 provided for improved VAST video, tablet and location targeting support. Release highlights include:
| October 2012 |
| OpenRTB 2.0 (PDF) OpenRTB 2.0 provided unified support for display, mobile, and video capabilities. This was a significant step forward for programmatic as allows for the harmonization of mobile and desktop advertising. Release highlights include:
| January 2012 |
IAB Tech Lab’s GitHub offers a reference implementation.
The following press releases and blog posts provide more information on OpenRTB.
If you have questions about OpenRTB, send an email to support to create a ticket.
Hillary Slattery, Director of Programmatic, Product hillary@iabtechlab.com