The 7 top-level domains, and every kind since
The seven top-level domains are the original generic endings of the internet: .com, .org, .net, .edu, .gov, .mil and .int. They are a piece of history, set down in a 1994 memo that said "It is extremely unlikely that any other TLDs will be created", and today there are 1,437 top-level domains.
This page explains where the seven came from, what kinds of ending exist now, how Australia's .au works, and how to choose one for a business here.
The original seven
A top-level domain is the last part of an address, the letters after the final dot. The list of seven comes from RFC 1591, written by Jon Postel in March 1994. It names "the generic TLDs (EDU, COM, NET, ORG, GOV, MIL, and INT), and the two letter country codes from ISO-3166", and gives each one a purpose:
| Ending | What it was meant for in 1994 |
|---|---|
| .com | Companies |
| .org | Organisations that fit nowhere else |
| .net | The computers of network providers |
| .edu | Four-year colleges and universities |
| .int | Organisations set up by international treaty |
| .gov | US federal government agencies |
| .mil | The US military |
The same memo says "five are international in nature, and two are restricted to use by entities in the United States". Those two are .gov and .mil.
Today only some of those purposes still hold. .com and .org are open to anyone: the US government's own get.gov says "Anyone can register a .com, .org, or .us domain for a fee", while .gov domains are "only available to U.S.-based government organizations". IANA, which manages the root of the internet's naming system, still limits .int to treaty organisations, UN agencies and bodies with observer status at the UN General Assembly.
The five that came first
If you were asked for "the five top-level domains", the answer is one step earlier. RFC 920, from October 1984, set out "The initial top level domain names": .gov, .edu, .com, .mil and .org, plus a temporary .arpa for the hosts already online, and country codes taken from the ISO list. .net and .int had joined by the time of the 1994 memo, which is how five became seven.
The kinds of top-level domain today
On 21 October 2026, IANA's list of top-level domains (version updated 20 October 2026) held 1,437 entries. Its root zone database sorts the active ones into three types:
- Generic: 1,127 of them. The original seven, the later additions and the brand and city names.
- Country code: 309 of them, for countries and territories, including 61 written in scripts other than Latin.
- Special use: one, .arpa, the survivor of 1984, now kept for technical names such as home.arpa.
You may also read about sponsored domains. In November 2000 ICANN, the body that oversees domain policy, picked seven new endings. Its own record says four (.biz, .info, .name and .pro) were unsponsored and three (.aero, .coop and .museum) were sponsored. ICANN's archive explains that a sponsored domain "has a sponsor representing the narrower community that is most affected by the TLD". IANA's database now files .museum and .aero simply as generic, though ICANN's own agreements for some of these endings still call them sponsored.
Recent top-level domains
The big change was ICANN's New gTLD Program. Applications opened on 12 January 2012, ICANN received 1,930 of them, and "In October 2013, the first new gTLDs were delegated". By ICANN's August 2026 count, 1,241 endings from that round had been delegated, which means switched on in the internet's root (ICANN does not subtract any removed since).
Two of them are Australian cities. .melbourne has been live since 10 July 2014 and is held by the State of Victoria, and .sydney since 5 November 2014, held by the New South Wales Department of Premier and Cabinet. Other familiar names from the round include .app (live since July 2015) and .shop (May 2016).
The program's next round, ICANN's 2026 round, is under way now. ICANN's 2026 round took applications from 30 April to 12 August 2026, and on 7 October ICANN published the list: 1,615 applications in its first count, 333 of them for brands. None has been delegated yet. The final list of applied-for names is due on 17 November 2026, and you can browse the applications yourself on ICANN's application site.
Special domains you cannot register
Some endings are set aside so they never clash with a real site. RFC 6761 reserves .test, .example, .invalid and .localhost, and tells registries they "MUST NOT grant requests to register" them. IANA keeps the full list of special-use names, which also includes .local and .onion. If you see .example or .test in a tutorial, it is a placeholder, not a place.
Is there a .est domain?
No. IANA's database has no .est, and among the 2,783 application records on ICANN's 2026 application site (replacement strings included) none asks for it, as we read them on 21 October 2026. If you were looking for Estonia, its ending is .ee. If you meant .estate, that one exists and has been live since November 2013. Before you plan around any ending, look it up in IANA's database.
Country codes, and why websites have them
A country-code domain is the ending given to a country or territory, usually two letters: .au, .nz, .uk. They were in the system from the start. RFC 920 provided for "The English two letter code (alpha-2) identifying a country", and RFC 1591 says each country domain is "organized by an administrator for that country".
That local administrator is the reason they exist. Each country sets its own rules, so an ending can tell a visitor something true about who runs the site. Google reads them the same way. Its guidance for international sites says country codes "provide a strong signal to both users and search engines that your site is explicitly intended for a certain country".
There are exceptions. Google treats a short list of country codes as generic "as we've found that users and website owners frequently see these more generic than country-targeted": .ai, .co, .io, .me and .tv are on it, among others.
How .au works
.au is run by auDA, "an Australian not-for-profit organisation, endorsed by the Australian Government to manage the .au domain". auDA lists these kinds of .au name:
| Address | Who it is for |
|---|---|
| .com.au | Businesses |
| .net.au | Businesses, often tech |
| .org.au | Not-for-profits |
| .asn.au | Associations and community groups |
| .id.au | Individuals |
| .edu.au | Education |
| .gov.au | Governments |
| .au | Anyone with a link to Australia |
There are state and territory names too. Each has rules. A .com.au is "for businesses with a connection to Australia", most often shown with an ABN or ACN, and the name must connect to your business: its name, an acronym of it, your trade mark, or a product or service you offer. auDA says 3.2 million com.au names are registered.
The newest is plain .au, which auDA calls ".au direct". It launched on 24 March 2022 and lets you register a name "directly before the .au". Its rules are looser: "anyone with a validated connection to Australia" can hold one, including citizens, permanent residents and Australian trade mark holders. auDA says you can choose any .au direct name you like, "provided it's available and you have permission to use it"; unlike a .com.au, it need not connect to a business.
.com or .net, .com or .biz
Google treats all three as generic endings, which it describes as "domains that aren't associated with specific locations". It says plainly that "Keywords in a TLD do not give any advantage or disadvantage in search", and it treats new endings "like other gTLDs (like .com and .org)".
So the choice is about people. Many people type .com without thinking, and an email to a .net address that someone types as .com goes to the wrong place. .biz came from ICANN's round of 2000 (IANA's record of its setting up is dated June 2001), and it is far less familiar to most people than .com. If the .com of your name is taken, a different name on .com, or the .com.au, usually serves you better than the same name on .net or .biz.
Why .to is popular
.to is the country code of Tonga, run by TONIC Domains, which says on its site that its registry "has been in operation by TONIC Domains since 1997" and that ".TO names work worldwide exactly the same as do .COM names". Its appeal is the word: "to" finishes a phrase in English, which makes for short, memorable addresses.
One thing to know before you buy. .to is not on Google's list of country codes it treats as generic, and Google says that by default most country codes result in it "using these to geotarget the website". So Google may read a .to as a site for Tonga. For a site that wants to be found in Australia, that is the wrong hint.
Which ending is best for an Australian business or startup
Start with two questions: where are your customers, and what are you eligible for?
Say you are opening Wattlegum Tiles, a tiling business in Geelong (our invented example), with an ABN and the business name registered. Your customers are local, so you want an Australian ending. You qualify for wattlegumtiles.com.au because it is your business name, and for wattlegumtiles.au because you have a link to Australia. Register the .com.au for the site and email, and take the .au as well, so nobody else holds the shorter version of your name. Then point the .au at the .com.au.
A software startup selling to the world is different. Your customers are everywhere, so a .com is the obvious home, and a .com.au can still sit alongside it for Australian buyers. A .io or .ai can work for a technical audience, since Google treats both as generic, but expect to explain it to everyone else.
If the .com.au you want is already registered, Dotto lists .com.au names for sale by their holders, some with an asking price and many open to offers.