What is the test_cookie cookie?
This cookie is set by DoubleClick (which is owned by Google) to determine if the website visitor's browser supports cookies.
Our October 2026 scan found it on 54 sites (2% of the 2,450 we scanned), set before any consent.
- Purpose
- Functional
- Belongs to
- DoubleClick/Google Marketing
- Set as
- Third-party (under another company's domain)
- Typical lifetime
- Under a day (vendor says: 1 year) — shorter than the vendor documents
Sites that set test_cookie before consent
The highest-ranked 30 of 54 sites.
- ivi.ru10 tracking companies
- npr.org9 tracking companies
- prnewswire.com13 tracking companies
- ryanair.com3 tracking companies
- hbr.org12 tracking companies
- seedtag.com4 tracking companies
- instructure.com17 tracking companies
- tabelog.com6 tracking companies
- tenki.jp27 tracking companies
- protothema.gr6 tracking companies
Show 20 more sites
- mechacomic.jp13 tracking companies
- animanch.com22 tracking companies
- cmu.edu6 tracking companies
- amocrm.ru6 tracking companies
- primis.tech11 tracking companies
- yotpo.com4 tracking companies
- proofpoint.com3 tracking companies
- mirtesen.ru4 tracking companies
- pwc.com5 tracking companies
- utoronto.ca5 tracking companies
- ubc.ca4 tracking companies
- riskified.com4 tracking companies
- heylink.me7 tracking companies
- directnic.com3 tracking companies
- moz.com11 tracking companies
- gm.com10 tracking companies
- vt.edu10 tracking companies
- cvent.com5 tracking companies
- tokopedia.com8 tracking companies
- iinet.net.au4 tracking companies
Related cookies
Other cookies from DoubleClick/Google Marketing.
- _gcl_au336 sites
- FCCDCF141 sites
- receive-cookie-deprecation136 sites
- __Secure-YNID113 sites
- g_state92 sites
How to stop it
Declining non-essential cookies in a site's consent banner should stop test_cookie 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.