What is the personalization_id cookie?
Unique value with which users can be identified by X. Collected information is used to be personalize X services, including X trends, stories, ads and suggestions.
Our October 2026 scan found it on 77 sites (3% 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 personalization_id before consent
The highest-ranked 30 of 77 sites.
- samsung.com4 tracking companies
- applovin.com8 tracking companies
- media.net6 tracking companies
- oxylabs.io11 tracking companies
- fidelity.com15 tracking companies
- instructure.com17 tracking companies
- nypost.com8 tracking companies
- hotpepper.jp13 tracking companies
- plos.org3 tracking companies
- jalan.net27 tracking companies
Show 20 more sites
- tenki.jp27 tracking companies
- oricon.co.jp36 tracking companies
- carsensor.net31 tracking companies
- gamewith.jp6 tracking companies
- testbook.com6 tracking companies
- kakuyomu.jp18 tracking companies
- trilltrill.jp23 tracking companies
- oddspark.com7 tracking companies
- mechacomic.jp13 tracking companies
- piccoma.com25 tracking companies
- alphapolis.co.jp9 tracking companies
- xfinity.com8 tracking companies
- vice.com14 tracking companies
- fastcompany.com17 tracking companies
- jhu.edu5 tracking companies
- hpe.com10 tracking companies
- primis.tech11 tracking companies
- laravel.com7 tracking companies
- verizon.com20 tracking companies
- politico.com31 tracking companies
Related cookies
Other cookies from X.
- muc_ads72 sites
- guest_id49 sites
- guest_id_ads49 sites
- guest_id_marketing49 sites
How to stop it
Declining non-essential cookies in a site's consent banner should stop personalization_id 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.