← Glossary
UID2 (Unified ID 2.0)
An open-source, email-based identifier standard for addressable advertising without third-party cookies.
Unified ID 2.0 is an open-source identity standard, originally built by The Trade Desk, that resolves a hashed and encrypted user email or phone number into a shared advertising identifier across participating publishers and platforms. It's used in CTV mainly on the authenticated, logged-in surfaces of AVOD and FAST apps rather than as a universal CTV identifier, since most connected TV viewing has no login or email associated with the device at all.