ORTB
EN

Version Diff 2.52.6

Mechanical diff (field sets / types / required; the 2.5 source is a pure 2.5 implementation) + the official Appendix B changelog · generated 2026-08-11

63 fields added6 fields removed0 fields changedObjects +13

Note: the baseline comparison is 2.5 → 2.6 base edition; zero field changes (type/required) is expected — such changes landed in later rolling revisions of 2.6 (202211+).

New objects in 2.6 (13)

BidRequest4 differences
Source1 differences
Regs4 differences
Imp5 differences
Banner4 differences
Video11 differences
Audio7 differences
Deal3 differences
Site3 differences
App3 differences
Publisher1 differences
Content10 differences
Producer1 differences
Device2 differences
User3 differences
Data1 differences
Bid6 differences

Official changelog (Appendix B · Version 2.5 to 2.6)

§3.2.1, 3.2.16, 4.2.3, 3.2.18Added new language field to support IETF BCP 47, IETF BCP 47 offers additional layers of granularity, for example, differentiating written language versions of the same spoken language (e.g. Traditional and Simplified Chinese), https://en.wikipedia.org/wiki/IETF_language_tag
§3.2.3Object: Regs added gdpr attribute (previously ext)
§3.2.20Object: User added consent attribute (previously ext)
§5Removed section (Enumerated Lists) All references now point to AdCOM 1.0 / OpenRTB 3.0 Lists
§3.2.1, 3.2.13, 3.2.14, 3.2.15, 3.2.16, 3.2.17, 4.2.3Objects: BidRequest, Site, App, Publisher, Content, Producer, Bid Use of cattax for all taxonomy references
§3.2.7, 3.2.8Objects: Video, Audio Added rqddurs
§3.2.7, 3.2.8Objects: Video, Audio Added maxseq, poddur, podid, podseq, mincpmpersec, slotinpod for pod bidding support
§4.4, 4.4.1Substitution Macros Added AUCTION_MIN_TO_WIN
§4.2.3Object, Bid Added apis
§3.2.4Object: Imp Added rwdd
§3.2.1, 3.2.14, 4.2.3Objects: App, Bid, BidRequest Clarified language around use of storeid vs bundle
§3.2.4Object Imp Added ssai
§3.2.18Object: Device Clarified language around mccmnc and roaming
§3.2.23, 3.2.24Added Objects: Network, Channel, SupplyChain, SupplyChainNode, EIDs and UIDs*
§4.2.3Object: Bid Added mtype
§3.2.6, 3.2.7, 3.2.16Removed previously deprecated attributes Object: Banner, wmax, hmax, wmin, hmin, Object: Video, protocol, Object: Content, videoquality
§7.6Pod Bidding for Video and Audio implementers guide
§7.7Network and Channel object examples
§3.2.7, 3.2.8, 3.2.18, 3.2.20, 4.2.3Deprecated attributes Object: Video, sequence, Object: Audio, sequence, Ojbect: Device, didsha1, didmd5, dpidsha1, dpidnd5, macsha1, macmd5, Object: User, yob, gender, Object: Bid, api
§7.8Added Counting Billable events and tracked ads
§3.2.29, 3.2.30Object: UserAgent & Object Brand Version added

The full changelog follows the official spec: openrtb2.x/2.6.md Appendix B (revisions after 2.6-202303 are on GitHub Releases).