Check if a site is included in HSTS preload list
HSTS (short for HTTP Strict Transport Security) is a mechanism that forcibly activates a secure connection via the HTTPS protocol.
Sites that use HSTS can notify clients about this in two ways:
1) using the strict-transport-security HTTP header.
2) using the HSTS preload list – a list of sites that can be connected to via the HTTPS protocol only.
This service checks if a site is included in the HSTS preload list.
You can check both second-level domain (SLD) and third-level and any other level subdomains, as well as top-level domains (TLD).
Examples:
- hackware.ru
- youtube.com
- paypal.com
- com
- net
- dev
- day
- microsoft
- youtube
- just.whatever.if.dev
- just.whatever.if.day