What is the SM cookie?

This is a Microsoft cookie which we use to measure the use of the website for internal analytics.

Our October 2026 scan found it on 11 sites (0% of the 2,450 we scanned), set before any consent.

Purpose: Analytics
Belongs to: Microsoft
Set as: First-party on 9% of sites, third-party on 91%
Typical lifetime: Session (vendor says: session)

Sites that set SM before consent

The highest-ranked 11 of 11 sites.

bing.com0 tracking companies
msn.com4 tracking companies
oxylabs.io11 tracking companies
tailscale.com7 tracking companies
cmu.edu6 tracking companies
crunchyroll.com4 tracking companies
ssl.com9 tracking companies
aarp.org30 tracking companies
guard.io14 tracking companies
reolink.com11 tracking companies

Show 1 more site

coxautoinc.com10 tracking companies

Related cookies

Other cookies from Microsoft.

MUID38 sites
ASP.NET_SessionId23 sites
_uetsid22 sites
_uetvid21 sites
MR16 sites

How to stop it

Declining non-essential cookies in a site's consent banner should stop SM 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.