What is a TLD (top-level domain)?
A TLD, or top-level domain, is the last part of a domain name, after the final dot: the .com in example.com or the .uk in bbc.co.uk. IANA keeps the official list in the DNS root zone. ICANN splits TLDs into two classes: generic, like .com and .app, and two-letter country codes, like .de and .io.
Updated October 26, 2026 · 14 primary sources, listed below
Where the TLD sits in a domain name
Domain names read right to left, from the most general label to the most specific. The TLD is the label furthest right. ICANN’s glossary puts it simply: in icann.org, “the characters org identify the TLD,” and the administrators of a TLD control which second-level domains exist under it. Take www.bbc.co.uk apart:
| Label | What it is | Who controls it |
|---|---|---|
| uk | The top-level domain, the country code for the United Kingdom | Nominet UK, the registry IANA lists for .uk |
| co | A second-level domain the registry created for companies | The same registry. co.uk is a public suffix: people register names under it, not it |
| bbc | The name the owner registered | The registrant, through a registrar |
| www | A subdomain | The owner, freely, with no registration |
That is why people use “TLD”, “domain extension” and “domain ending” loosely for both .uk and .co.uk. Only .uk is the TLD; .co.uk is an ending you can register under. For .com there is no middle layer: example.com sits directly under the TLD.
The kinds of TLD, counted from today’s root zone
The IANA root zone database is the authoritative list. As of October 25, 2026 it holds 1,437 live TLDs. ICANN splits them into two classes, generic and country code; how they behave when you try to buy one splits them into four:
| Kind | Live now | Who can register |
|---|---|---|
| Open generic (gTLD) .com, .org, .app, .xyz | 729 | Anyone, through an accredited registrar. |
| Country code (ccTLD) .de, .uk, .io, .ai | 309 | Set by each country’s registry. Many are open to all; some need a local presence. |
| Restricted or sponsored .edu, .gov, .museum, .bank | 56 | Only the sector or community the registry serves. |
| Brand (dot-brand) .google, .apple, .bmw | 343 | Nobody: the operator keeps it for its own use. |
Restricted covers the TLDs IANA lists as sponsored or restricted, the community TLDs bound by Specification 12 of their ICANN registry agreement, and .arpa, which runs internet infrastructure. Brand TLDs are the ones with Specification 13, the dot-brand terms. Across all four kinds, 151 are internationalized TLDs written in non-Latin scripts, such as .рф (Russia) and .中国 (China).
Two catches buyers hit. First, some country codes are sold worldwide as if they were generic: .io, .ai and .co are ccTLDs, and Google treats them as generic for search (see whether a non-.com hurts rankings). Second, country rules differ a lot: .de is open to anyone, .ca is not (see the residency rules).
Who runs a TLD
Three layers sit between you and a domain:
- IANA manages the root zone: it assigns the manager of each TLD and records it. IANA is run by Public Technical Identifiers, an affiliate of ICANN, and ICANN sets the policy for generic TLDs.
- The registry runs one or more TLDs and keeps the master list of names in them. IANA lists VeriSign Global Registry Services for .com and Internet Computer Bureau Limited for .io.
- The registrar sells you the name. ICANN accredits registrars to sell generic TLDs, and prices for the same TLD vary between them, especially at renewal. We compare them.
How the list grew from a handful to over a thousand
In March 1994, RFC 1591 by Jon Postel listed the generic TLDs as .edu, .com, .net, .org, .gov, .mil and .int, plus two-letter country codes from ISO 3166, and said: “It is extremely unlikely that any other TLDs will be created.”
It was not. ICANN’s New gTLD Program received 1,930 applications in 2012, and the first new TLDs entered the root zone in October 2013. That round produced most of the endings you see today, from .app to .xyz. The 2026 round took applications from 30 April to 12 August 2026; see what’s coming next.
Names that will never be TLDs
RFC 2606 reserves four names so they never clash with a real TLD: .test for testing DNS code, .example for documentation, .invalid for names that must fail, and .localhost for your own machine. None of them is in the root zone, and you cannot register a domain in any of them.
Where to go next
- Browse all 1,437 TLDs, filtered to the ones anyone can register.
- How to choose a domain name: length, ending, renewal price and trademarks.
- The best TLD for your kind of project, ranked.
- Check a name across endings, with live availability.
Common questions
Is a TLD the same as a domain extension?
In everyday use, yes: "domain extension" and "domain ending" mean the TLD. Strictly, an ending like .co.uk is two labels: .uk is the TLD and co is a second-level domain under it. The Public Suffix List tracks every ending people can register under, including ones like co.uk.
What is the difference between a gTLD and a ccTLD?
A ccTLD (country-code TLD) is a two-letter ending tied to a country or territory, like .de or .ca, and each country's registry sets its own rules. A gTLD (generic TLD) is every other ending, like .com, .org or .app. Some ccTLDs, like .io, .ai and .co, are marketed worldwide as if they were generic.
Who decides which TLDs exist?
ICANN sets the policy and approves new generic TLDs. IANA, run by Public Technical Identifiers (an ICANN affiliate), records each TLD and who manages it in the DNS root zone. A registry then runs each TLD, and accredited registrars sell names in it to the public.
How many TLDs are there?
More than 1,400 are live in the IANA root zone. The exact count, split by kind, is at the top of this page and updates whenever IANA publishes a new version of the root zone list.
Can I create my own TLD?
Only by applying to ICANN's New gTLD Program and becoming a registry. The 2012 round received 1,930 applications. The 2026 round took applications from 30 April to 12 August 2026. A TLD you invent on your own network is not reachable on the public internet.
Does the TLD I choose affect Google rankings?
Not by itself. Google says its systems treat new gTLDs like other gTLDs such as .com and .org, and keywords in a TLD give no advantage or disadvantage. Country codes can signal a country to Google, except ones like .io and .co that Google treats as generic.
Sources
- ICANN, “Glossary: top-level domain (TLD)” (retrieved October 26, 2026).
- IANA, “Root Zone Management” (retrieved October 26, 2026).
- IANA, “Root Zone Database (the Top-Level Domain Registry)” (retrieved October 26, 2026).
- IANA, “List of top-level domains in the root zone” (retrieved October 26, 2026).
- IANA, “About IANA (operated by Public Technical Identifiers, an ICANN affiliate)” (retrieved October 26, 2026).
- ICANN, “Registrars: what an accredited registrar is” (retrieved October 26, 2026).
- ICANN, “ICANN registry agreements (Brand Spec 13, Community Spec 12)” (retrieved October 26, 2026).
- ICANN New gTLD Program, “About the 2012 round” (retrieved October 26, 2026).
- ICANN New gTLD Program, “2026 Round” (retrieved October 26, 2026).
- IETF, “RFC 1591: Domain Name System Structure and Delegation (J. Postel)” (March 1, 1994).
- IETF, “RFC 2606: Reserved Top Level DNS Names” (June 1, 1999).
- Mozilla, “Public Suffix List” (retrieved October 26, 2026).
- Google Search Central Blog, “Google's handling of new top level domains (John Mueller)” (July 21, 2015).
- Google Search Central, “Managing multi-regional and multilingual sites (gccTLD list)” (December 10, 2025).
Extensions on this page
More straight answers
- How to come up with a business name (and a domain that goes with it)
- How to check if a business name is taken
- How to choose a domain name for your business
- Will using a non-.com domain hurt my Google rankings?
- Starting an app in Brazil: should you use .com.br or .com?
- Can I register a .de or .ca domain if I don't live in that country?
- Should I buy the .net and .co versions of my domain to protect my brand?
- Will emails from a .xyz or .io address go to spam?
- Is it risky to build my company on a .io domain because of the Chagos Islands deal?
- How much will a .ai domain cost over 5 years, including renewals?
- Why does my .dev site require HTTPS, and can I turn it off?