Whoisology is described as 'searchable domain name reverse whois / ownership database with over one billion individual domain name records that are updated pretty regularly'. There are more than 10 alternatives to Whoisology, not only websites but also apps for Windows and Self-Hosted solutions. The best alternative is DomainTools, which is free. Other great sites and apps similar to Whoisology are Domain Checker (Freemium), CubDomain (Free), Whois (Free) and EZwhois (Free).
Obtain domain name status information with this effective and intuitive application that allows you to batch process multiple entries. Domain Checker is a simple, but powerful whois lookup tool for users that require a domain availability analyzer.