What is a TLD?

Last updated October 26, 2026

A top-level domain, or TLD, is the last part of a domain name, after the final dot. For example, in the domain name dnsimple.com the TLD is .COM.

The IANA root zone lists about 1,400 TLDs, but not all of them are open for registration. For more information about available and supported TLDs, check the list of TLDs supported by DNSimple for registration and transfer.

Tip

Even if a TLD is not supported for registration or transfer, you can still add the domain to your account to use DNSimple for the DNS hosting or other domain services such as purchasing an SSL certificate.

TLDs are generally grouped into three categories:

gTLD (Generic Top-Level Domains): this is the most common and well-known category. It includes general-purpose extensions such as the .COM, .NET, .ORG, .INFO, and many others.
ccTLD (Country-Code Top-Level Domains): this category includes all the extensions used or reserved for a country, sovereign state, or dependent territory identified with a country code. Notable examples are .US, .CA, and .UK.

Some ccTLDs have become so popular that they are often mistaken for gTLDs. This is, for instance, the case of the .IO TLD very popular in the internet/tech industry, or the .CO TLD that has been widely used as a replacement for .COM.
New gTLDs (New Generic Top-Level Domains): this category includes the generic TLDs created through ICANN’s New gTLD Program, which opened applications for new TLDs in 2012.

This category contains hundreds of TLDs. Just to name a few: .SHOP, .EMAIL, .XYZ, etc.

For per-extension requirements, transfers, and registry rules, the TLDs at DNSimple guide links to documentation for each supported extension.

Have more questions?

If you have any questions about TLDs or domain registration, just contact support, and we will be happy to help. You can also read more about domain registration at DNSimple.