OpenRTB (Real-Time Bidding)

Support for iOS14 privacy changes

Apple announced a number of privacy related updates in iOS14, which impact how in-app advertising and attribution works. We have released a set of OpenRTB extensions to support these updates, along with a couple of optimizations that we would like to get feedback on. Please provide your feedback to by October 16th.

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 with feedback or questions.

Read the November 2018 blog post announcement: Final Specs

View the OpenRTB 3.0 final specification, including ads.cert Beta

View OpenMedia Specifications: 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 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.

Previous Versions
Version Release Date
OpenRTB 2.5 (PDF)
OpenRTB 2.5 includes updated 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
December 2016
OpenRTB 2.4 (PDF)
OpenRTB 2.4 main improvements:



  • Video skippability support
  • SSL Support
  • New audio object created
  • Increased location support
March 2016
OpenRTB 2.3.1 (PDF)
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.
June 2015
OpenRTB 2.3 (PDF)
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.
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:



  • 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
April 2014
OpenRTB 2.1 (PDF)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
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:



  • 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
January 2012

Supporting Resources

OpenRTB Advisory – GDPR
Tech Lab CodeBank: OpenRTB
Tech Lab Tool: OpenRTB Bid Validator
OpenRTB Security Advisory 15-01 (PDF) Released December 2015
Guidance for DSPs and SSPs to mitigate botnet attack optimization tactics.

Extensions to OpenRTB

The new version 1.2 of the OpenRTB Dynamic Native Ads API Specification is in public review. Some of the added features include support for third-party ad serving, dynamic creative optimization (DCO), privacy flags, and new event tracking options. Please review and send your questions or any feedback to by May 17, 2017.

Download the OpenRTB Native 1.2 Draft for Public Review (PDF)

Related Documents

The IAB Tech Lab Releases Updates To Three Programmatic Protocols (Blog Post)

IAB Tech Lab Releases Two Major Updates to OpenRTB (MediaPost)

IAB Tech Lab Releases Protocols For OpenRTB (Press Release)

Developed by the OpenRTB Working Group

IAB Tech Lab Contact

Amit Shetty
Senior Director, Video & Audio Products