Website privacy check
What a site sets, loads and passes on before you've agreed to anything.
Checks run in parallel, and slow ones time out rather than hold up the rest.
What gets checked
What this tells you
By the time a page has finished loading, most sites have set cookies, pulled in third-party scripts and told several other companies that the visit happened.
The domain leaks in the other direction too. WHOIS privacy is either switched on or it isn't, and the answer is public either way.