How Can You Tell Whether a TLD Is Real?
· Reference · IANA
Quick answer
How can you tell whether a TLD is real?
Check the extension against the IANA delegated TLD list. If the string is not in the public root zone, it is not a normally registrable public TLD — it may be an internal name, a special-use name such as .onion, or a made-up marketing term. For anything that is delegated, also check the registry’s eligibility rules before assuming you can register it.
Three checks, in order
Start with the authoritative list rather than a search result or a registrar’s landing page. Then separate "exists" from "available to you".
- Look up the exact string in the IANA delegated list (the plain-text file is easiest to grep).
- Check its classification: generic, country-code, internationalized or special-use.
- Check the registry’s eligibility rules — delegation does not imply anyone may register.
Common false positives
Special-use names such as .onion are reserved for a specific technical purpose and are not sold as ordinary domains. Internal or made-up suffixes used inside a company network are also not part of the public root zone. Internationalized TLDs add another trap: the Unicode form you see and the punycode (xn--) form used in DNS are the same delegation written two ways.
Why this matters before you pay
A non-delegated suffix cannot be a normal public domain, so any invoice for one deserves scrutiny. Even for a delegated TLD, a very cheap first year can hide a restricted renewal policy or a local-presence requirement. Verify the extension, then verify the terms.
Frequently asked questions
Is .onion a real TLD?
It is a special-use name reserved for a technical purpose, not a public TLD you can register through a normal registrar. It is not part of the ordinary delegated root zone catalogue.
Why do some TLDs appear as xn-- names?
Internationalized domain names are written in Unicode for people and encoded as punycode (an xn-- prefix) for DNS. Both forms refer to the same delegation.
Can I trust a registrar that offers an extension I cannot find on IANA?
Ask for clarification before paying. It may be a subdomain product, a private namespace or a marketing name rather than a delegated TLD.
Sources
Primary sources for the claims above.