What is the cna cookie?
A persistent device identifier set by Alibaba Group's statistics service (mmstat.com), used across Taobao, Tmall and related sites to recognize a returning device.
Our October 2026 scan found it on 14 sites (1% of the 2,450 we scanned), set before any consent.
- Purpose
- Analytics
- Belongs to
- Alibaba Group
- Set as
- First-party on 43% of sites, third-party on 57%
- Typical lifetime
- 13 months
Sites that set cna before consent
The highest-ranked 14 of 14 sites.
- alibaba.com7 tracking companies
- aliexpress.com1 tracking company
- taobao.com0 tracking companies
- youku.com0 tracking companies
- umeng.com1 tracking company
- cctv.com0 tracking companies
- 1688.com0 tracking companies
- tmall.com0 tracking companies
- dingtalk.com0 tracking companies
- lazada.co.id1 tracking company
Show 4 more sites
- lazada.com.ph1 tracking company
- lazada.sg1 tracking company
- uc.cn0 tracking companies
- alibaba-inc.com0 tracking companies
How to stop it
Declining non-essential cookies in a site's consent banner should stop cna 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.