What is the _uetsid cookie?
This cookie is used by Bing to determine what ads should be shown that may be relevant to the end user perusing the site.
Our October 2026 scan found it on 22 sites (1% of the 2,450 we scanned), set before any consent.
- Purpose
- Advertising
- Belongs to
- Bing / Microsoft
- Set as
- First-party (under the site's own domain)
- Typical lifetime
- 1 day (vendor says: 30 minutes)
Sites that set _uetsid before consent
The highest-ranked 22 of 22 sites.
- media.net6 tracking companies
- oxylabs.io11 tracking companies
- tailscale.com7 tracking companies
- instructure.com17 tracking companies
- twilio.com9 tracking companies
- hpe.com10 tracking companies
- crunchyroll.com4 tracking companies
- ssl.com9 tracking companies
- audible.com25 tracking companies
- redis.io12 tracking companies
Show 12 more sites
- aarp.org30 tracking companies
- simplisafe.com31 tracking companies
- heylink.me7 tracking companies
- zapier.com3 tracking companies
- xero.com18 tracking companies
- guard.io14 tracking companies
- vt.edu10 tracking companies
- island.io17 tracking companies
- teacherspayteachers.com5 tracking companies
- ana.co.jp16 tracking companies
- reolink.com11 tracking companies
- bankrate.com9 tracking companies
Related cookies
Other cookies from Bing / Microsoft.
- MUID38 sites
- ASP.NET_SessionId23 sites
- _uetvid21 sites
- MR16 sites
- ai_session13 sites
How to stop it
Declining non-essential cookies in a site's consent banner should stop _uetsid 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.