_uetsid — Microsoft Advertising (UET)
By the OpenCookies team · published 2026-10-22 · updated 2026-10-22
- Service
- Microsoft Advertising (UET)
- Category
- Advertising and profiling
- Default duration
- 1 day
- Type
- First-party cookie (set by your own site)
- Consent required?
- Yes, before any storage or reading.
What is it for?
Identifies a session for the Microsoft Advertising UET tag (conversion tracking). It goes with _uetvid, valid for 13 months.
What does it look like?
The value is a random hexadecimal string.
How to see it in your browser
Open your site, press F12, then choose the “Application” tab (Chrome, Edge) or “Storage” (Firefox). Under “Cookies”, select your site’s address: the _uetsid cookie appears in the list if present, with its value and expiry date.
What does the rule say?
Targeted advertising, remarketing and profiling require prior, free and informed consent. These cookies cannot be exempted.
How to prevent it before the choice
Do not load the UET tag before consent.
How OpenCookies handles it
Common services like this one are in OpenCookies’ tracker list: the banner neutralizes their script before the visitor chooses and only restarts it after “Accept”. The test shows whether this cookie appears before the choice, after “Refuse” and after “Accept”.
Check it on my site
Does this cookie appear on your site before the visitor chooses? The OpenCookies test shows it in two minutes.
Related cookies
Frequently asked questions
What is the difference from _uetvid?
_uetsid identifies the session (one day); _uetvid identifies the visitor (13 months).
What is the UET tag for?
It measures conversions of Microsoft Advertising (Bing) campaigns.
Durations are defaults and may change with configuration. This page describes a cookie; it is not legal advice.