// supercookies
what is HSTS supercookie?
Encode an id in the HSTS pin-state of N subdomains: per bit, decide whether to teach the browser to force-HTTPS that subdomain, then later probe each over HTTP and watch which upgrade to read the bits back.. Fast-decaying: browser mitigations land release-to-release; asOf 2026-06-15. Distilled from the richards supercookies catalog.
source capture as of 2026-06-15
in the benchmark
HSTS supercookie is tracked as part of the supercookies taxonomy. see how tracked tools score against it on the capability matrix.