OpenRTB (Real-Time Bidding)

OpenRTB 3.0 Finalized and Ready for Adoption

OpenRTB 3.0 is the largest overhaul of the OpenRTB protocol since its inception in 2010. The purpose of this major update is to meet the market’s demand for security, transparency, authentication, and trust in programmatic advertising. New structure for programmatic specifications means that where OpenRTB 2.x was previously used alone, now OpenRTB 3.0 AND AdCOM 1.0 should be used in tandem.

This overhaul saw a thorough review process within the OpenRTB working group and the public. In June 2018 the IAB Technology Laboratory released  for public comment the tech specifications for OpenRTB 3.0, built upon the framework released September 2017, as the second part of a two-phase introduction to the ecosystem to promote healthy growth digital advertising programmatic marketplace. Specifications designed to support OpenRTB 3.0 were also available for public comment, including: ads.cert: Signed Bid Requests, AdCOM, and the Ad Management API.

Please reach out to [email protected] with feedback or questions.

Read the November 2018 Blog Post Announcement: Final Specs

View the OpenRTB 3.0 Final Spec, Including Ads.Cert Beta

View OpenMedia Specs: AdCOM 1.0 and Ad Management 1.0

Note: The new structure of the OpenRTB 3.0 Beta specification requires use of both OpenRTB (transactional specification) AND AdCOM (specification describing objects to be transacted). This layered specification approach is referred to as “OpenMedia.”  Previous 2.X versions of OpenRTB were standalone specifications.

Previous Versions | Supporting Resources | Related Documents | OpenRTB Extensions

About OpenRTB

Real-time Bidding (RTB) is a way of 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 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.

Previous Versions: 

OpenRTB API Specification V 2.5

OpenRTB Dynamic Native Ads API Specification Version 1.2

OpenRTB API Specification – Previous Versions

OpenRTB 2.5, released January 2017

OpenRTB 2.5 includes updates that integrate current trends and allows for improvements in programmatic technology. Release highlights include:

  • IAB New Ad Portfolio Support – integrating flexible aspect-ratio based ads into the bid object
  • Video Placement Type Support – adding visibility into what type of placement a VAST (video ad serving template) tag is running in accordance to the IAB digital video glossary
  • Header Bidding Support – allowing for a signal when a bid request is originated from an upstream decisioning implementation like header bidding
  • Historic Metrics Support – whereby exchanges can pass historic metrics such as viewability or click through rate

OpenRTB 2.4, released March 2016

OpenRTB 2.4 introduces a brand new advertising medium to the protocol: digital audio. This is also the largest update to OpenRTB to date which includes improvements to private marketplace transactions, ability to declare skippable video ads, and additional fields in the bid-response allowing for more granular reporting capabilities. Release highlights include:

  • Introduction of encryptions by supporting both HTTP and HTTPS
  • New audio object created
  • Increased location support allowing buyers to know which IP source was used to derive a given geo-location and when the latitude/longitude was last fetched using the device location service
  • Video skippability support for in-stream advertisements

OpenRTB 2.3.1, released June 2015

OpenRTB 2.3.1 provides an update to the specification addressing two typos:

  • Section 3.2.13 – In the user object, the buyer ID attribute has been corrected to “buyeruid.”
  • Section 4.4 – The ${AUCTION_BID_ID} macro has been corrected to be substituted with the “BidResponse.bidid” attribute.

OpenRTB 2.3, released January 2015

The OpenRTB 2.3 specification provides support for native ads. This is 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:

  • Native ad placements must be included directly into the impression object in order to be passed through the bidstream.
  • Allows for the inclusion of metadata (title, urls, data, img files) in the native request. The buy side now has the ability to describe the unit that’s being bid on and the supply side is able to define which fields are available and required in order to assemble the native ad.
  • Updates to the style of the document including improved diagrams and revamped table format to support the continued commitment to OpenRTB.

OpenRTB 2.2.1, released July 2016

OpenRTB 2.2, released April 2014

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:

  • Support to the allow for the differentiation of secure and nonsecure inventory.
  • Exhaustive Deal ID support for Private Marketplaces
  • Improved backing for new types of mobile and video inventory
  • Ability for buyers to alert sellers in real time about suspected bot traffic
  • COPPA regulation support

OpenRTB 2.1, released October 2012

OpenRTB 2.1 provided for improved VAST video, tablet and location targeting support. Release highlights include:

  • IAB Tier-2 category support
  • Recognition of tablet inventory
  • VAST video across RTB;  the video object must represent an impression as either banner, video or both
  • Location source support; differentiation of GPS derived and zip code value targeting

OpenRTB 2.0, released January 2012

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:

  • VAST ad unit support
  • Improved geographical data definition
  • Increased cross-channel support for mobile and desktop through a common API language.
  • Improved 3rd party data segment support for audience targeting
  • Enhanced attribution support; inclusion of device IDs in mobile & mobile app parameters

Extensions to OpenRTB

OpenRTB Dynamic Native Ads V1.2, released July 2017

Version 1.2 of the OpenRTB Dynamic Native Ads API Specification has been finalized. Some of the added features include support for third-party ad serving, dynamic creative optimization (DCO), privacy flags, and new event tracking options. Any questions or comments for the OpenRTB Native working group can be sent to [email protected].

Download the OpenRTB Dynamic Native Ads API Specification Version 1.2

OpenRTB Dynamic Native Ads API Specification Version 1.1, released March 2016

The Native Ads API 1.1 includes market-demanded improvements and features corresponding to the IAB Deep Dive on In-Feed Ad Units.  Release highlights include:

  • Further articulate semantics of the “seq” parameter
  • Creative element standardization through the creation of two new fields; Context and Placement Type

Download the OpenRTB Dynamic Native Ads API Specification V1.1

OpenRTB Dynamic Native Ads API Specification Version 1, released February 2015

This spec describes the outer native object, which includes the ad unit (the 6 types of native ads defined by the IAB Native Advertising Playbook) and the layout.  While the Native Ads API is designed to be used with OpenRTB, it provides a set of fundamentals that are useful in non-RTB environments like in-app SDK object description.

Guidelines and Advisories

OpenRTB Security Advisory 15-01, released December 2015

Guidance for DSPs and SSPs to mitigate botnet attack optimization tactics.

For more information or to join the OpenRTB Working Group, contact Jennifer Derke, Senior Manager, Product, at the IAB Tech Lab at [email protected].

Visit IAB Tech Lab’s OpenRTB page for supporting resources and tools.