Provides a privacy-first, interoperable identity framework that enables addressable advertising without third-party cookies while giving users transparency and control over their data.
Last updated Feb 8, 2026
Leading open-source identity solution for programmatic advertising
Unified ID 2.0 (UID2) is an open-source identity framework developed by The Trade Desk and now governed by Prebid.org as an independent industry initiative. It serves as a privacy-conscious alternative to third-party cookies for digital advertising, enabling deterministic identification based on encrypted and hashed email addresses and phone numbers. UID2 allows users to opt-in and opt-out of targeted advertising while providing advertisers, publishers, and ad tech platforms with a consistent identifier across the programmatic advertising ecosystem. As a critical infrastructure component in the post-cookie advertising landscape, UID2 has gained significant adoption across major publishers, demand-side platforms (DSPs), supply-side platforms (SSPs), and data providers. The framework emphasizes transparency, user control, and interoperability, positioning itself as a universal standard that can work across multiple platforms and participants in the digital advertising supply chain. Unlike proprietary walled garden solutions, UID2's open-source nature and governance by an independent organization aim to create a level playing field for the entire industry.
Core identity infrastructure that generates encrypted tokens from hashed email addresses and phone numbers for advertising targeting and measurement
User-facing transparency and control center where consumers can view and manage their UID2 opt-out preferences
Service that generates, manages, and refreshes UID2 tokens while maintaining security and privacy controls
Software development kits for publishers, advertisers, and ad tech platforms to integrate UID2 functionality