// domain glossary
TLD (top-level domain).
A TLD, or top-level domain, is the final label in a domain name — .com, .co.uk, .io, .ai — and it determines which registry runs the name, what it costs to renew and which lifecycle rules it follows.
The TLD is the rightmost part of the name, and it is the entry in the DNS root zone that everything below it hangs from. The root is administered by IANA, and there are now well over a thousand delegated TLDs, which is a great many more than the handful most people can name.
They come in families. Legacy gTLDs (.com, .net, .org) are the originals. The 2012 expansion added several hundred new gTLDs (.app, .dev, .studio, .xyz and the rest), most of them run as commercial ventures. ccTLDs are assigned to countries and territories, though several are marketed globally with no local connection whatsoever — .io, .ai and .co being the familiar examples. There are also sponsored TLDs restricted to particular communities, and internationalised TLDs in non-Latin scripts. The important consequence is that ccTLD registries answer to national policy rather than ICANN, so their transfer rules, privacy options and deletion lifecycles can differ substantially from the gTLD norm.
Economically, the TLD sets the floor. Its registry fixes the wholesale fee every registrar pays, so your choice of extension determines the minimum you will pay for as long as you hold the name — and some carry structural terms besides, such as .ai's two-year minimum registration. Registrar shopping can close the gap between retail prices, but nobody can arbitrage away a registry price increase. That makes the TLD decision the one with the longest tail, which is why it deserves more thought than picking whatever was cheap that week. See what each one actually costs to renew.
There is a reputational dimension too. TLDs are not treated equally by spam filters, link scanners and corporate security tooling; several inexpensive newer extensions carry enough abuse history that mail sent from them gets filtered and links to them get flagged, regardless of how legitimate your project is. If the domain will send email or appear in anyone's procurement process, that risk outweighs a few pounds on the registration. Domain search flags the extensions with a poor deliverability record, and ranks alternatives on five-year cost rather than the first-year teaser — see total cost of ownership for why that is the right ranking.
// stop checking one at a time
knowing the terms is the easy part.
Owndle tracks every domain you own across every registrar — what each one costs to renew, what you would save moving it, and when it expires. Free for your first ten domains.
start free — 10 domains →// no card · magic-link sign-in · alerts at 90/30/7/1 days