IANA TLD Checker is a new tool available at
It currently uses an algorithm for dynamically caching and refreshing results.
Use it to check if a domain name has been registered across IANA’s top-level domains (tlds). Most IANA’s tlds are supported (generic, themed, countries/cities-specific, IANA’s regions-specific, and others including those available through Google and CentralNic.
The tool can be used to quickly check for possible branded domains or if someone is infringing on your intellectual property by registering domain names with your brand(s). So it can be used to supplement whois searches.
The tool can also be used to discover IPs not intended for public view. See instructions in the TLD Intelligence section of the tool’s page.
UPDATE: We added a new set of options at the bottom of the selection menu that allows you to search alphabetically. This set of options retrieves tlds from IANA’s site on a daily basis, allowing you to retrieve domains with tlds not found through the other options. At the time of writing, you can access a combined set of 1,167 tlds.