What is the _cq_duid cookie?
Used by the website to protect against fraud in relation to its referral system.
Our October 2026 scan found it on 19 sites (1% of the 2,450 we scanned), set before any consent.
- Purpose
- Functional
- Belongs to
- CHEQ AI Technologies
- Set as
- First-party (under the site's own domain)
- Typical lifetime
- 3 months (vendor says: 3 months) — about what the vendor documents
Sites that set _cq_duid before consent
The highest-ranked 19 of 19 sites.
- amplitude.com5 tracking companies
- klaviyo.com4 tracking companies
- mailchimp.com4 tracking companies
- twilio.com9 tracking companies
- screenconnect.com7 tracking companies
- ringcentral.com0 tracking companies
- riskified.com4 tracking companies
- mapquest.com10 tracking companies
- cvent.com5 tracking companies
- backblaze.com1 tracking company
Show 9 more sites
- jumpcloud.com2 tracking companies
- creditkarma.com11 tracking companies
- globalnews.ca10 tracking companies
- ana.co.jp16 tracking companies
- liquidweb.com3 tracking companies
- bankrate.com9 tracking companies
- marksandspencer.com10 tracking companies
- volkswagen.de0 tracking companies
- washingtontimes.com21 tracking companies
How to stop it
Declining non-essential cookies in a site's consent banner should stop _cq_duid 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.