You can query all subdomains of the root domain. Enjoy it!
Rapiddns currently has more than 5 billion DNS resolution data, supporting A, CNAME, AAAA, MX types. A records 3.1 billion, CNAME records 760 million, AAAA records 395 million and MX records 886 million. Can query the domain name of the same IP website (support IPv6). You can also query subdomain information.