What is the pi cookie?
This cookie enables us to determine which set of pixels needs to be executed on the browser.
Our October 2026 scan found it on 47 sites (2% of the 2,450 we scanned), set before any consent.
- Purpose
- Advertising
- Belongs to
- PubMatic
- Set as
- First-party on 13% of sites, third-party on 87%
- Typical lifetime
- 13 months (vendor says: 1 day) — longer than the vendor documents
- Where it's common
- 62% of the sites that set it use a .ru domain.
Sites that set pi before consent
The highest-ranked 30 of 47 sites.
- dzen.ru3 tracking companies
- mts.ru3 tracking companies
- yandex.com0 tracking companies
- ivi.ru10 tracking companies
- cdnvideo.ru2 tracking companies
- ya.ru1 tracking company
- livejournal.com11 tracking companies
- pikabu.ru6 tracking companies
- tbank.ru4 tracking companies
- gismeteo.ru14 tracking companies
Show 20 more sites
- rutube.ru1 tracking company
- playhop.com6 tracking companies
- sozcu.com.tr11 tracking companies
- rambler.ru9 tracking companies
- russianfood.com6 tracking companies
- hh.ru5 tracking companies
- mirtesen.ru4 tracking companies
- kinopoisk.ru2 tracking companies
- magnit.ru6 tracking companies
- ria.ru4 tracking companies
- slate.com20 tracking companies
- yandex.com.tr0 tracking companies
- narod.ru5 tracking companies
- profi.ru4 tracking companies
- ctvnews.ca38 tracking companies
- lenta.ru9 tracking companies
- yandex.kz0 tracking companies
- askona.ru8 tracking companies
- aviasales.com3 tracking companies
- stuff.co.nz19 tracking companies
Related cookies
Other cookies from PubMatic.
- KTPCACOOKIE15 sites
- KADUSERCOOKIE14 sites
- chkChromeAb67Sec6 sites
- SyncRTB*6 sites
- chk5 sites
How to stop it
Declining non-essential cookies in a site's consent banner should stop pi 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.