What is HSTS (HTTP Strict Transport Security)? | UpGuard

HSTS is a web security policy that forces browsers to use HTTPS, preventing downgrade/SSL-stripping, man-in-the-middle, and session hijacking by rejecting insecure connections and automatically upgrading HTTP to HTTPS. The report explains how the Strict-Transport-Security header works (including max-age, includeSubDomains, preload), outlines limitations like first-visit exposure and dependence on preload/DNSSEC, and provides deployment best practices and ramp-up guidance. It also notes broad browser support and the history of the standard (RFC 6797).