What Is a TLD? Top-Level Domains Explained
Quick answer
A TLD, or top-level domain, is the last part of a domain name after the final dot, such as .com, .org or .uk. TLDs sit at the top of the DNS hierarchy and are listed in the root zone managed by IANA. The main types are generic TLDs (gTLDs) and country-code TLDs (ccTLDs).
A TLD (top-level domain) is the part of a domain name that comes after the last dot. In example.com, the TLD is .com. In example.org.uk, it is .uk. TLDs are the highest level of the Domain Name System (DNS), and every one of them is listed in the root zone, which IANA (operated by an affiliate of ICANN) maintains.
How a TLD fits into a domain name
Domain names are read from right to left, from most general to most specific:
| Part | In blog.example.com | What it is |
|---|---|---|
| Top-level domain | .com | The extension, run by a registry |
| Second-level domain | example | The name you register |
| Subdomain | blog | Created by the owner; see what a subdomain is |
When someone visits a website, DNS resolvers start at the root, ask which servers are responsible for the TLD, then ask those servers about the specific domain. Our guide to what DNS is explains the full lookup.
The main types of TLD
Generic TLDs (gTLDs)
Generic TLDs are not tied to a country. They include the originals such as .com, .net and .org, and hundreds of newer ones such as .shop, .app, .blog and .online. Most gTLDs are open to anyone, but some have restrictions; for example, .bank is limited to verified banks.
Country-code TLDs (ccTLDs)
Every ccTLD is two letters and is based on a country or territory code, such as .uk, .de, .ca and .jp. Each is run under policies set locally. Some are open to anyone worldwide, which is why .io, .ai, .co and .tv are popular with startups and media brands. Others require a local presence.
Sponsored TLDs (sTLDs)
These serve a specific community and are run by a sponsoring organisation, such as .edu (accredited US post-secondary institutions), .gov (US government) and .museum.
Brand TLDs
Since ICANN’s 2012 new gTLD round, some companies have operated their own TLDs, such as .google or .bmw, usually for their own use only.
Infrastructure TLD
.arpa is used for technical internet infrastructure, such as reverse DNS lookups, not for public registration.
Internationalised TLDs (IDNs)
Some TLDs use non-Latin scripts, for example Chinese, Arabic or Cyrillic characters, so people can use domains entirely in their own language.
Who runs a TLD?
Three groups are involved:
- IANA maintains the root zone and records which organisation operates each TLD.
- The registry operator runs the TLD’s database and nameservers. Verisign runs .com and .net, and Public Interest Registry runs .org. Country registries run most ccTLDs.
- Registrars sell domains to the public and pass registrations to the registry.
For gTLDs, the registry and its registrars sign contracts with ICANN and follow ICANN policies, such as the transfer and expiry rules. ccTLD registries set their own policies.
A short history
The first generic TLDs, including .com, .org, .net, .edu, .gov and .mil, were introduced in the mid-1980s, alongside country codes. RFC 1591, published in 1994, set out the early structure and how TLDs were delegated. A handful of new gTLDs were added in the 2000s, and ICANN’s 2012 New gTLD Program then added more than a thousand. ICANN has been preparing a further application round; check the New gTLD Program site for its current status.
How many TLDs are there?
More than 1,400 TLDs are delegated in the root zone, though the exact number changes as new ones launch and some brand TLDs are retired. The authoritative list is IANA’s root zone database.
How to choose a TLD
| If you want… | Consider |
|---|---|
| The most familiar, trusted option | .com |
| To show you serve one country | That country’s ccTLD, such as .uk or .ca |
| A non-profit or community feel | .org |
| A descriptive name when the .com is taken | A relevant new gTLD such as .shop or .studio |
| A tech-startup signal | .io, .ai or .co, but expect higher prices |
Check renewal prices before you commit, since some TLDs are cheap in year one and expensive afterwards. Compare the classics in com vs net vs org, and see how much a domain costs for typical price ranges.
Frequently asked questions
Is a TLD the same as a domain extension?
Yes, in everyday use. "Domain extension" is the common term for the TLD, such as .com or .shop. Strictly, something like .co.uk combines a second-level label with the .uk TLD.
How many TLDs are there?
More than 1,400 are listed in the IANA root zone database, including generic, country-code and brand TLDs. The number changes as TLDs are added or retired, so check IANA's database for the current list.
Does the TLD affect SEO?
Generic TLDs are treated much the same by search engines. Country-code TLDs can signal that a site targets a particular country, which may help locally but limit international reach.
Can I create my own TLD?
Only by applying to ICANN in a new gTLD application round, which involves a large application fee, technical and financial requirements and the ongoing running of a registry. It is realistic only for large organisations.
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