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:
Other ways to use subdomains:
- go.example.website | info.example.website
- static.example.website | f.example.website
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:
Subdomains aren’t only for websites; third-level domains are also used for nameservers, i.e.:
- The 50 most popular subdomains (Bitquark, 2016)
- Top 40 Google Subdomains
- Popular Site Domains (i.e. amazon.com, bing.com, cnn.com, etc.) [github last updated September 2017]
- The most popular subdomains on the internet (2017 edition) ~ by Max Dymond
- Yet another enumeration of subdomains with statistics (Feb 2022) identified these top 10 subdomains: