What is the sa-user-id* cookie?
StackAdapt's advertising identifier, used to recognize a visitor across sites in its ad network for targeting and frequency capping. Versioned variants (e.g. sa-user-id-v2, -v3) appear as StackAdapt updates its identifier scheme.
Our October 2026 scan found it on 20 sites (1% of the 2,450 we scanned), set before any consent.
- Purpose
- Advertising
- Belongs to
- StackAdapt
- Set as
- Third-party (under another company's domain)
- Typical lifetime
- 12 months
- Name
- A family of cookies: the part after sa-user-id varies by site or account.
Sites that set sa-user-id* before consent
The highest-ranked 20 of 20 sites.
- inmobi.com12 tracking companies
- hbr.org12 tracking companies
- tapad.com12 tracking companies
- bollyflix.free7 tracking companies
- hdhub4u.bi8 tracking companies
- unicef.org13 tracking companies
- arizona.edu9 tracking companies
- scmp.com17 tracking companies
- kochava.com4 tracking companies
- virginia.edu7 tracking companies
Show 10 more sites
- webflow.com3 tracking companies
- idnes.cz42 tracking companies
- rutgers.edu12 tracking companies
- uwaterloo.ca7 tracking companies
- uga.edu7 tracking companies
- sundaysky.com16 tracking companies
- acorns.com20 tracking companies
- island.io17 tracking companies
- rediff.com42 tracking companies
- channelnewsasia.com24 tracking companies
How to stop it
Declining non-essential cookies in a site's consent banner should stop sa-user-id* 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 written by CookieTosser, for a cookie the Open Cookie Database doesn't cover.
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.