HSTS Preload Checker

Check whether a domain is on the browsers' HSTS preload list and run hstspreload.org's own requirements against it: the header, the redirects and the subdomain rules.

We ask hstspreload.org (the list Chrome, Firefox, Safari and Edge build in) for the domain's status and its own checklist.

Check a live site

The SSL Certificate Checker reads the certificate your server actually sends, its chain, revocation, CAA and renewal health.

Open the SSL Certificate Checker