This TechWelkin tool helps you in extracting only the domain names from a given list of URLs. This tool removes the protocol part (http:// or https://) and also the folders, files name, as well as parameters. [Learn about structure of a URL]
You will however get the subdomain (if it exists). You can also choose to remove the duplicate domain names from the result. If you find any problem with this tool, please report by sending an email to techwelkin AT gmail DOT com