most commonly used subdomains, aka third level domains

Looking to learn from the most popular subdomains that are commonly used on the Internet? I was looking, and thought it’d be a good thing to share what I found. Your help in adding to this list would be most appreciated. 

Even though statistics for data-informed results on what the top subdomains actually are, this is a list of 3rd level domains that you probably recognize being in active use, both by people and by server-to-server or client-to-server Internet communications. Some of the more frequently used subdomains:

  • http://www.example.website
  • m.example.website
  • http://ftp.example.website
  • imap.example.website
  • pop.example.website
  • smtp.example.website
  • mail.example.website
  • webmail.example.website
  • blog.example.website
  • wiki.example.website
  • support.example.website
  • kb.example.website
  • help.example.website

Other ways to use subdomains:

  • go.example.website | info.example.website
  • static.example.website | f.example.website
  • api.example.website
  • dev.example.website
  • events.example.website
  • feeds.example.website
  • forums.example.website
  • groups.example.website
  • img.example.website
  • media.example.website
  • news.example.website
  • sites.example.website
  • admin.example.website
  • mysql.example.website
  • store.example.website
  • vpn.example.website
  • admin.example.website
  • beta.example.website
  • photos.example.website
  • files.example.website
  • resources.example.website
  • secure.example.website
  • ssl.example.website
  • apps.example.website
  • pic.example.website
  • status.example.website
  • mobile.example.website
  • search.example.website
  • live.example.website
  • videos.example.website
  • lists.example.website
domainame

As illustrated in this diagram, technically, “www” is a third-level domain, and the second-level domain is part of a domain name “before the dot” and the top-level domain is the suffix or extension to the “right of the dot.” What’s usually called a domain name, generically, most often refers to both the second-level domain and the top-level domain. In mathematical notation, then, domain name = second-level domain + top-level domain.

And saw this configured in the default DNS records via a couple shared hosting services; some other subdomains that may be used:

  • localhost.example.website
  • autoconfig.example.website
  • autodiscover.example.website
  • webdisk.example.website

Subdomains aren’t only for websites; third-level domains are also used for nameservers, i.e.:

  • ns1.example.website
  • ns2.example.website
  • ns3.example.website

Other references

Subdomains Lists

Subdomains Tools and Articles