What is the __cf_ob cookie?
We don't have a vendor description for this cookie yet, but our scan shows it's set by Vimeo, and it is usually gone once the browser closes (a session cookie). It's listed as unclassified.
Our October 2026 scan found it on 42 sites (2% of the 2,450 we scanned), set before any consent.
- Purpose
- Unclassified
- Belongs to
- Vimeo
- Set as
- First-party on 67% of sites, third-party on 33%
- Typical lifetime
- Session
Sites that set __cf_ob before consent
The highest-ranked 30 of 42 sites.
- vimeo.com0 tracking companies
- medium.com2 tracking companies
- pubmatic.com1 tracking company
- hostgator.com3 tracking companies
- wired.com2 tracking companies
- klaviyo.com4 tracking companies
- outbrain.com1 tracking company
- kick.com3 tracking companies
- apnews.com14 tracking companies
- agora.io0 tracking companies
Show 20 more sites
- ancestry.com5 tracking companies
- theatlantic.com4 tracking companies
- ultimate-guitar.com0 tracking companies
- ficbook.net1 tracking company
- stackexchange.com0 tracking companies
- action.com3 tracking companies
- myinstants.com6 tracking companies
- indown.io3 tracking companies
- orcid.org2 tracking companies
- snowflake.com3 tracking companies
- fliphtml5.com2 tracking companies
- atom.com2 tracking companies
- politico.com31 tracking companies
- innovid.com3 tracking companies
- upwork.com1 tracking company
- home-assistant.io0 tracking companies
- polymarket.com3 tracking companies
- getyourguide.com4 tracking companies
- envato.com1 tracking company
- sfu.ca8 tracking companies
Related cookies
Other cookies from Vimeo.
- vuid12 sites
How to stop it
Declining non-essential cookies in a site's consent banner should stop __cf_ob 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.
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.