Unified ID 2.0 (UID2) is an open-source identity framework developed by The Trade Desk as a privacy-conscious alternative to third-party cookies. UID2 aims to enable advertisers and publishers to deliver personalized ads while respecting user privacy and data control. It works by converting a user’s email address (shared with consent) into an encrypted, regularly refreshed identifier.

Unlike cookies, which track users passively, UID2 is built on transparency and user consent, aligning more closely with privacy regulations like GDPR and CCPA.

How UID2 Works

• User Opt-In: Users voluntarily share their email (e.g., when logging into a website or app).

• Tokenization: The email is hashed and encrypted into a UID2 token—this token is regularly rotated to enhance security.

• Controlled Use: Publishers, advertisers, and ad tech partners can use UID2 tokens for ad targeting, frequency capping, and measurement—without revealing the original email.

• User Control: Users can revoke consent or opt out of UID2 usage at any time via a centralized portal or participating platforms.

This system supports addressable advertising while respecting privacy, even in cookie-less environments like iOS or Chrome post-3rd-party-cookie phase-out.

Why UID2 Matters

As privacy laws evolve and browsers phase out cookies, UID2 provides a scalable, privacy-centric identity solution. It empowers brands to maintain ad effectiveness while staying compliant with global data protection laws. Its transparency, consent-based model, and open standard make UID2 a strong candidate for the future of identity in digital marketing.