I'm currently using NameBright, it's quick and allows you to bulk check 5000 domain at once, but it does still not suit my purpose. I'm looking for something more powerful. What tool you guys use to check availability of let's say 1 million or more domains in a short period of time? Are there any paid tools or APIs allows you to do that? I should support popular extensions including .com, , org, .net & .co. Any help would be greatly appreciated.