What is the x-ms-gateway-slice cookie?
Identifies a gateway for load balancing.
Our October 2026 scan found it on 3 sites (0% of the 2,450 we scanned), set before any consent.
- Purpose
- Functional
- Belongs to
- Bing / Microsoft
- Set as
- Third-party (under another company's domain)
- Typical lifetime
- Session (vendor says: End of session (browser))
Sites that set x-ms-gateway-slice before consent
The highest-ranked 3 of 3 sites.
- msn.com4 tracking companies
- xbox.com1 tracking company
- powerbi.com1 tracking company
Related cookies
Other cookies from Bing / Microsoft.
- MUID38 sites
- ASP.NET_SessionId23 sites
- _uetsid22 sites
- _uetvid21 sites
- MR16 sites
How to stop it
Declining non-essential cookies in a site's consent banner should stop x-ms-gateway-slice 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.