Tech blog:Find a good available .com domain

2022-06-08 If you need a new domain name, and you want a .com, and you dont want to type random ideas into a registrar search, heres a way to do it.

Download the list of all registered .com domains

First, apply for access to the zone file, using ICANNs Centralized Zone Data Service (CZDS) at https://czds.icann.org/. Its free, but takes a few days to get approved. Read more about it here.

Once approved, they email you a password to log in and download the file called com.txt.gz.

<pre>$ du -hs com.txt.gz # 4.6GB compressed4.6G com.txt.gz$ gunzip com.txt.gz # uncompress and wait$ du -hs com.txt23.0G com.txt # 23 gigs uncompressed$ wc -l com.txt404261754 com.txt # 404 million lines</pre> Extract the unique names

com.txt has 404 million lines like this:

<pre>zombahomes.com. 172800 in ns ns2.tierra.net.zombai.com. 172800 in ns ns1.parkingcrew.net.zombai.com. 172800 in ns ns2.parkingcrew.net.zombaid.com. 172800 in ns nsg1.namebrightdns.com.zombaid.com. 172800 in ns nsg2.namebrightdns.com.zombaimmo.com. 172800 in ns ns10.lwsdns.com.zombaimmo.com. 172800 in ns ns11.lwsdns.com.zombaimmo.com. 172800 in ns ns12.lwsdns.com.zombaimmo.com. 172800 in ns ns17.lwsdns.com.zombaio.com. 172800 in ns ns-1073.awsdns-06.org.</pre> Domains usually have more than one entry. You need to extract the unique entries. And you only need the part before the .com.

Heres a Ruby script that loops through com.txt, gets the part before .com, skips it if duplicate, and outputs it if unique.

domain = ''File.open('com.txt', 'r') do |infile|  File.open('domains.txt', 'w') do |outfile|    while line = infile.gets      temp = line[0...(line.index('.com'))]      next if temp == domain      domain = temp      outfile.puts domain    end  endend

download code domains.txt should now be about 162 million lines - (about 2.2GB) - that look like this:

<pre>zombahomeszombaizombaidzombaimmozombaio</pre> Load it into SQLite, and index it.

<pre>$ sqlite3 domains.db sqlite> create table domains(domain text);sqlite> .import "domains.txt" domainssqlite> create index dd on domains(domain);</pre> Find available dictionary words

If youre on Mac, Linux, or BSD, you should have a dictionary of words at /usr/share/dict/words. See which of those words are available:

require 'sqlite3'db = SQLite3::Database.new('domains.db')query = db.prepare('select domain from domains where domain = ?')File.readlines('/usr/share/dict/words').each do |word|  rows = query.execute(word.downcase.strip)  puts word unless rows.nextend

download code Run that, and youll have a list of 93,000 dictionary words that are available with the .com extension. Congratulations! Go to porkbun.com (a great little registrar) to register yours.

Youll find that some are not actually available because that com.txt file doesnt list domains on hold, pending deletion, or without name servers.

Combine short dictionary words

If you are not excited that electrotelethermometer.com or counterexcommunication.com is available, maybe you would like a combination of two short words? Select only dictionary words up to four letters, then search for the combination.

require 'sqlite3'words = File.readlines('/usr/share/dict/words').map(&:strip)words.select! {|w| w.size <= 4}db = SQLite3::Database.new('domains.db')query = db.prepare('select domain from domains where domain = ?')words.each do |word1|  words.each do |word2|    combo = (word1 + word2).downcase    rows = query.execute(combo)    puts combo unless rows.next  endend

download code Narrow it down to good words

If you ran that last script, youll get tens of millions of available domains like knabtuik.com because there are many unknown, ugly, and useless short words.

So make a new file called goodwords.txt of only three and four letter words, using grep:

<pre>$ grep "^...$" /usr/share/dict/words >> goodwords.txt$ grep "^....$" /usr/share/dict/words >> goodwords.txt</pre> Edit that file by hand, deleting every word you would never want. (The less you keep, the better.) Then run that Ruby script again, combining just the good words:

require 'sqlite3'words = File.readlines('goodwords.txt').map(&:strip)db = SQLite3::Database.new('domains.db')query = db.prepare('select domain from domains where domain = ?')words.each do |word1|  words.each do |word2|    combo = (word1 + word2).downcase    rows = query.execute(combo)    puts combo unless rows.next  endend

download code Much better, right? A little time consuming, but worth it. This is how I found the name of my new translation service, Inchword.

Need it super-short and nerdy?

One final hack is that there are tons of very-short .com domain names available in the format letter-number-letter-number. For example: q7r7.com or e3p3.com.

require 'sqlite3'db = SQLite3::Database.new('domains.db')query = db.prepare('select domain from domains where domain = ?')('a'..'z').each do |a|  ('0'..'9').each do |b|    ('a'..'z').each do |c|      ('0'..'9').each do |d|        combo = a + b + c + d        rows = query.execute(combo)        puts combo unless rows.next      end    end  endend

download code