Identity

Unified ID 2.0 (UID2) — Definition & Explanation

An open-source identity framework that creates encrypted, anonymized identifiers from email addresses. UID2 provides deterministic cross-device matching without third-party cookies and has gained broad industry adoption.

How Unified ID 2.0 (UID2) Works

Publishers collect email addresses from authenticated users and pass hashed emails to the UID2 operator, which generates an encrypted token. This token is passed in bid requests so buyers can match against their CRM data without accessing the raw email.

Why Unified ID 2.0 (UID2) Matters for Publishers

UID2 enables publishers to maintain audience addressability for their authenticated users after third-party cookie deprecation, protecting CPMs for logged-in traffic.

Frequently Asked Questions

How do I implement UID2 on my site?

UID2 requires collecting email addresses from users and integrating the UID2 JavaScript SDK. Stellor Media can guide implementation for publisher partners.

Who operates the UID2 framework?

UID2 is governed by the Trade Desk with oversight from an independent board. It's an open-source framework available to all publishers.

Does UID2 require user consent?

Yes. Users must consent to their email address being used for advertising purposes under applicable privacy regulations before their email can be processed for UID2.

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