Glossary of Domain-Related Terms

TLD

A top-level domain is either a gTLD or a ccTLD. For all domains, a TLD is the last part of the domain name, what comes after the last dot.

Some interpret gTLDs and ccTLDs by themselves as TLDs (correct), and others interpret a domain registered directly below a TLD (e.g. "google.com") as a TLD (incorrect). Domains that aren't TLDs are subdomains (e.g. .eu.org), but sometimes those are TLDs too (e.g. .co.uk).

With the advent of sponsored new gTLDs circa 2014, the valid suffixes became almost too numerous to manage. Mozilla maintains a public suffix list.

Find further discussion in the domain vs. subdomain article.

gTLD

A generic top-level domain. The list of suffixes initially comprised .com, .net, .org, .edu, .gov, and .mil, but was since expanded with .int, .aero, .biz, .info, .name, .pro, .asia, .blog, .dev, .jobs, .website, .game, .app, .xxx and over 1200 others!

Some of those domain suffixes are sponsored TLDs, which means you may need to meet special, arbitrary criteria to obtain one from the party that registered them.

If you want to see examples of sites using these TLDs, you can search Google with 'site:' parameter, e.g. site:travel.

ccTLD

A country code top-level domain is a TLD generally used or reserved for use by entities within a country. ccTLDs are two characters long, and they (mostly) correspond to ISO 3166 alpha-2 country codes.

Some free (sub)domains on our list are ccTLDs, but that doesn't mean you can't register them if you're from another country. Google and other search engines understand that some ccTLDs are often used in domain hacks, such as del.icio.us, please.do.not.disturb.me, which means they have a wider intended audience, so the search engines treat them as gTLDs. Such domains have a green checkmark symbol (✅) in the Geo-targetable column in our list.

IDN

Internationalized domain names are those that contain at least one non-ASCII script or character. For example, domains with characters from Arabic or Chinese alphabets are IDNs. In most browsers, you can access such internationalized domain names normally.

Some free domain providers from our list support IDNs, and those that do are marked accordingly in the IDN column. Note that they may not support Unicode characters directly (e.g. registering domain škřåṫčé.com may not work) in which case you first have to convert your desired domain name to Punycode (e.g. škřåṫčé.com becomes xn--k-2fam7l2oqb5928a.com in Punycode). You can convert normal text to punycode here.

Domains and subdomains that support registering IDNs therefore also support emoji domains (sometimes only via Punycode).

Punycode

See IDN.

Geo-Targeting

Geo-Targeting is a legacy feature of Google Search Console, where a webmaster can set her domains as targeting a particular country.

All gTLDs are geo-targetable, but so are some vanity ccTLDs, those that are most commonly used in domain hacks. For example, a dot-com domain can be targeted to any specific country or no country in particular, and so can a .tk domain. On the other hand, .ie domains cannot be geo-targeted to any region, save Ireland.

When a domain is geo-targeted, it will show up more often in that country's version of Google Search (e.g. in Google.de or within results made to queries in that country's target language (e.g. "auto" in German). Read more about Google's geotargeting settings, and find a list of ccTLDs considered generic here. In our list, geo-targetable free domains are marked with a green checkmark symbol (✅) in the Geo-targetable column.

But focus on the website content and don't worry about it too much.

DNS Records

The Domain Name System (DNS) is a hierarchical, distributed naming system that translates human-readable domain names and hostnames to machine-readable numbers such as IP addresses. Propagated via nameservers, most common DNS record types are:

A

Holds a 32-bit IP(v4) address. The domain name points to, and your web browser contacts, the server at this address.

AAAA

Holds a 128-bit IPv6 address.

CNAME

Points to another domain name as its alias. That alias' A or AAAA record is then used to make the web request.

MX

Mail eXchange records point to mail servers responsible for handling the domain's email.

NS

This records delegates the whole DNS zone (the collection of records for the domain) to the specified name servers.

SOA

Usually specifies authoritative information about a DNS zone, e.g. the primary name server, administrative contact, domain serial number, and several timers related to refreshing the zone.

TXT

Originally, TXT record stored arbitrary human-readable text in a DNS zone, but nowadays more often carries machine-readable data such as SPF policy and DKIM cryptographic keys.

Age

In our comparison table, the Age column represents the number of years of free domain service. The longer, the better.

Some free domain providers are more reliable than others, some have reputation to uphold. Others may disappear without notice. You wouldn't want to be hosted by one of the latter, would you?

Indexed

If the subdomains of a particular domain registrar are present in the Google Search index (i.e. not banned), then they have a green checkmark symbol (✅) in that column.

It is important to realize that some free domains attract all sorts of crooks that need a place to host their malware. Sometimes search engines ban the whole TLD if the malice is too widespread. These bans are temporary and last anywhere from 90 days to couple of years. This will hapen until spammers stop taking advantage, or more likely, until the providers manage to identify threats sooner and curb them more efficiently.

Domain Parking

Domain parking is the registration of a domain name without it being "developed" into a service such as a website.

People park domains mostly as a means of reservation for future development or to resell it to an interested party with a hefty premium. Those people are also called domain squatters, and they are the bully kids nobody likes.