Bot? check if a domain name is availible?

Solution 1:

On windows you can use

nslookup <domain name> 

Example:

C:\>nslookup abc.com
Server:  pd1nsc1.st.vc.XXXXX.net
Address:  64.59.144.XX

Non-authoritative answer:
Name:    abc.com
Address:  199.181.132.250

Example no domain:

C:\>nslookup abceeeeeeeeeeeeeeeeeeeeee.com
Server:  pd1nsc1.st.vc.XXXXX.net
Address:  64.59.144.XX

*** pd1nsc1.st.vc.shawcable.net can't find abceeeeeeeeeeeeeeeeeeeeee.com: Non-ex
istent domain

Every 3 letter domain has been registered on .com, .net, .org... I believe its the same with 4 letter domains, i think there is still some 5 letter domains left.

Solution 2:

Asking for all three-letter domains from the .com, .net, and .org servers should take about 17576 queries to each, so 52,728 total. Should take about 15 minutes to write the script, and a few minutes to run.

It won't get you exactly what you want, as not being in DNS does not exactly mean it is free. However, it's a good start.

Solution 3:

You should expect that all three-letter domains are taken and many are available for sale. Google is your friend (or perhaps not).