What is the guest_id_marketing cookie?
This cookie is for advertising when logged out.
Our October 2026 scan found it on 49 sites (2% of the 2,450 we scanned), set before any consent.
- Purpose
- Advertising
- Belongs to
- X
- Set as
- Third-party (under another company's domain)
- Typical lifetime
- 13 months (vendor says: 2 years) — shorter than the vendor documents
Sites that set guest_id_marketing before consent
The highest-ranked 30 of 49 sites.
- applovin.com8 tracking companies
- oxylabs.io11 tracking companies
- nypost.com8 tracking companies
- hotpepper.jp13 tracking companies
- jalan.net27 tracking companies
- testbook.com6 tracking companies
- kakuyomu.jp18 tracking companies
- trilltrill.jp23 tracking companies
- oddspark.com7 tracking companies
- mechacomic.jp13 tracking companies
Show 20 more sites
- alphapolis.co.jp9 tracking companies
- xfinity.com8 tracking companies
- vice.com14 tracking companies
- fastcompany.com17 tracking companies
- hpe.com10 tracking companies
- primis.tech11 tracking companies
- laravel.com7 tracking companies
- siriusxm.com10 tracking companies
- audible.com25 tracking companies
- suno.com9 tracking companies
- heylink.me7 tracking companies
- ventraip.net.au8 tracking companies
- asahi.com41 tracking companies
- thehindu.com7 tracking companies
- libsyn.com8 tracking companies
- moz.com11 tracking companies
- drpc.org6 tracking companies
- bybit.com6 tracking companies
- nicovideo.jp24 tracking companies
- guard.io14 tracking companies
Related cookies
Other cookies from X.
- personalization_id77 sites
- muc_ads72 sites
- guest_id49 sites
- guest_id_ads49 sites
How to stop it
Declining non-essential cookies in a site's consent banner should stop guest_id_marketing 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.