Unified ID 2.0

Leading open-source cookie alternative for programmatic advertising, adopted by 50%+ of US programmatic ad spend by mid-2025 and backed by The Trade Desk

Unified ID 2.0 (UID2) is an open-source identity framework designed to enable publishers, advertisers, and digital advertising platforms to establish and maintain user identity across the open internet, leveraging encrypted email and phone number data to deliver a privacy-conscious and accurate identity standard.^1,2 It emerged as an upgrade to third-party cookies, preserving the core value exchange of relevant advertising while strengthening consumer controls, and many in the industry expect it to become one of several new identity standards that replace cookies.³ Advertising with UID2 enables the use of first-party data to power omnichannel campaigns across devices through a single identifier, including in environments where cookies are absent, such as connected TVs and mobile apps.⁴ Designed with the needs of modern marketers in mind, UID2 provides holistic, privacy-centric targeting and measurement capabilities.⁵ Adoption spans a broad range of the ad tech ecosystem, including supply-side platforms such as Index Exchange, Magnite, PubMatic, and OpenX, publishers such as MediaVine, FuboTV, and The Washington Post, and measurement provider Nielsen, which has made UID2 a core element of its upgraded measurement portfolio.³ Source 1: prebid.org — Unified ID 2.0 for Header Bidding Source 2: adtechexplained.com — Unified ID 2.0 Explained Source 3: thecurrent.com — What the Tech is Unified ID 2.0? - The Current Source 4: amperity.com — About Unified ID 2.0 (UID2) - Reference Source 5: thetradedesk.com — Because advertising matters