HSTS Preload Check

Is a domain on the browsers' HSTS preload list, and does it meet the requirements to join? With the cautions to read before submitting.

The HSTS preload list is built into Chrome, Edge, Firefox and Safari: browsers on it never try plain HTTP for the domain or any of its subdomains, not even the very first visit. This check asks hstspreload.org, which runs the list, whether a domain is on it and whether it meets the requirements to be added. Being on the list is hard to undo, so read the cautions before submitting.