What is the uuid2 cookie?
This cookie contains a unique randomly-generated value that enables the Platform to distinguish browsers and devices.
Our October 2026 scan found it on 16 sites (1% of the 2,450 we scanned), set before any consent.
- Purpose
- Advertising
- Belongs to
- Xandr
- Set as
- Third-party (under another company's domain)
- Typical lifetime
- 3 months (vendor says: 90 days) — about what the vendor documents
Sites that set uuid2 before consent
The highest-ranked 16 of 16 sites.
- alibaba.com7 tracking companies
- dell.com12 tracking companies
- olx.com.br10 tracking companies
- carsensor.net31 tracking companies
- immobiliare.it6 tracking companies
- kakuyomu.jp18 tracking companies
- scmp.com17 tracking companies
- santander.com.br7 tracking companies
- tokopedia.com8 tracking companies
- hepsiburada.com6 tracking companies
Show 6 more sites
- iu.edu15 tracking companies
- netshoes.com.br15 tracking companies
- ana.co.jp16 tracking companies
- mercadopago.com8 tracking companies
- rediff.com42 tracking companies
- homes.com17 tracking companies
Related cookies
Other cookies from Xandr.
- XANDR_PANID16 sites
- anj14 sites
How to stop it
Declining non-essential cookies in a site's consent banner should stop uuid2 being set on later visits. Blocking third-party cookies in your browser settings stops the third-party kind everywhere, and clearing cookies for a site removes any it already set.
Description from the Open Cookie Database (Apache 2.0).
Understanding this page
- How cookie lifetimes work, and why a 13-month _ga matters
What a cookie's "expires" field actually controls, why Google Analytics ships a 2-year default that many sites cut down to 13 months, and how Safari's 7-day cap on script-set cookies changes the picture.
- First-party vs third-party cookies (and why "first-party" still tracks you)
What the distinction actually means technically, why browsers only block one of the two, and how CNAME cloaking, server-side tagging and cookies like _ga let sites keep tracking under their own domain.
- How to block or limit trackers
Browser privacy settings, content blockers, Global Privacy Control and clearing cookies compared honestly — what each one actually stops, what it doesn't, and what it costs you in return.