What is the utm_* cookie?
A generic prefix many sites use to copy UTM campaign-tracking parameters (utm_source, utm_medium, utm_campaign and similar) from the URL into a cookie, so the traffic source that brought a visitor in can still be attributed as they move between pages.
Our October 2026 scan found it on 13 sites (1% of the 2,450 we scanned), set before any consent.
- Purpose
- Analytics
- Belongs to
- Various
- Set as
- First-party (under the site's own domain)
- Typical lifetime
- 15 days
- Name
- A family of cookies: the part after utm_ varies by site or account.
Sites that set utm_* before consent
The highest-ranked 13 of 13 sites.
- vtb.ru4 tracking companies
- trellix.com3 tracking companies
- elastic.co2 tracking companies
- threatlocker.com5 tracking companies
- n-able.com5 tracking companies
- walkme.com2 tracking companies
- 58.com0 tracking companies
- hootsuite.com7 tracking companies
- lazada.co.id1 tracking company
- lazada.com.ph1 tracking company
Show 3 more sites
- lazada.sg1 tracking company
- netshoes.com.br15 tracking companies
- bluestacks.com2 tracking companies
How to stop it
Declining non-essential cookies in a site's consent banner should stop utm_* 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.