I wanted to share a new tool I’ve been using to access historical WHOIS information for websites. It also lets you search by registrant name to find all domains where a company or person appears in the historical WHOIS data. There’s also a DNS search feature that shows current and historical DNS and IP connections between domains.
The tool is called WhoIsXMLAPI, and you get a chunk of free API credits when you sign up!
In my old job we subscribed to DomainTools for this, but it’s super expensive. This is a much more affordable (free at first!) option that’s been super useful in my investigations.