What is the _dd_s cookie?
Set by Datadog's Real User Monitoring (RUM) library to track session information, such as the session ID and its expiry, for browser performance monitoring.
Our October 2026 scan found it on 49 sites (2% of the 2,450 we scanned), set before any consent.
- Purpose
- Analytics
- Belongs to
- Datadog
- Set as
- First-party (under the site's own domain)
- Typical lifetime
- Under a day
Sites that set _dd_s before consent
The highest-ranked 30 of 49 sites.
- paypal.com1 tracking company
- base.org2 tracking companies
- datadoghq.com14 tracking companies
- go.com3 tracking companies
- cnbc.com9 tracking companies
- eventbrite.com2 tracking companies
- zillow.com4 tracking companies
- pexels.com4 tracking companies
- nbcnews.com20 tracking companies
- nationalgeographic.com2 tracking companies
Show 20 more sites
- olx.com.br10 tracking companies
- giphy.com2 tracking companies
- lanacion.com.ar14 tracking companies
- hotpepper.jp13 tracking companies
- marktplaats.nl4 tracking companies
- abc.net.au4 tracking companies
- jalan.net27 tracking companies
- oricon.co.jp36 tracking companies
- trilltrill.jp23 tracking companies
- mechacomic.jp13 tracking companies
- intercom.com0 tracking companies
- va.gov2 tracking companies
- siriusxm.com10 tracking companies
- getyourguide.com4 tracking companies
- railway.app2 tracking companies
- hotwire.com2 tracking companies
- callrail.com2 tracking companies
- clickup.com3 tracking companies
- thomsonreuters.com3 tracking companies
- sueddeutsche.de5 tracking companies
How to stop it
Declining non-essential cookies in a site's consent banner should stop _dd_s 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 written by CookieTosser, for a cookie the Open Cookie Database doesn't cover.
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.