tldlist.us/Methodology

Methodology: how we compile the TLD list

Every figure on tldlist.us traces back to an authoritative source. This page explains exactly where our TLD data comes from, how we classify and price extensions, and how often the list is refreshed — so you can trust what you cite.

Sources in one line

TLD names and registries come from the IANA root zone database; types and restrictions follow ICANN and registry policy; example sites and indicative prices are compiled from public registrar data and reviewed regularly.

1. The list of TLDs

The set of valid top-level domains is not a matter of opinion — it is defined by the internet root zone. We use the IANA Root Zone Database, the official registry of every delegated TLD maintained by the Internet Assigned Numbers Authority on behalf of ICANN, as our master reference for which extensions exist and which organization operates each one. tldlist.us curates the most useful 100+ of those for buyers and developers rather than reproducing the full ~1,440-entry root zone.

2. How we classify each TLD

We use the same three-way split that IANA and ICANN use:

TypeDefinitionHow we determine it
gTLDGeneric top-level domain — open, not tied to a country.IANA "generic" classification
ccTLDCountry-code TLD — a two-letter code from the ISO 3166-1 country list.IANA "country-code" classification
sTLDSponsored TLD — operated for a defined community under eligibility rules.IANA "sponsored" classification

Note: a few country-code TLDs (such as .io, .co, .ai, .tv and .me) are technically ccTLDs but are marketed and used generically worldwide. We label these as ccTLDs but describe their generic use in the "meaning" column.

3. Registry information

The "registry" for each TLD — the organization that runs it in the root zone — is taken from the IANA delegation record for that TLD. Registries do change over time (for example through acquisitions and re-delegations), so this field is part of every refresh cycle.

4. How prices are determined

Domain prices are set by registrars, not by us, and they vary widely. The "typical price" we show is an indicative annual figure in US dollars chosen to represent a normal standard rate across mainstream registrars — deliberately not the lowest promotional first-year price, because those promotions expire and the renewal is what you actually pay long-term.

5. Example sites

Example websites are real, well-known live sites chosen to show how an extension reads in practice. They are illustrative and do not imply any endorsement of, or by, tldlist.us.

6. Update cadence

We review the dataset on a regular schedule and after major events in the domain industry — such as ICANN delegating new gTLDs, registry re-delegations, or notable price changes. Each page shows a visible "Last updated" date so you always know how current the information is. The dataset's machine-readable form is described in the Dataset structured data on the homepage.

7. Corrections

If you spot an error — an outdated registry, a wrong price band, a mislabeled type — email [email protected]. We correct verified issues promptly and update the page date.

Independence: tldlist.us is operated independently by Mustafa Bilgic and is not affiliated with ICANN, IANA or any registry. Advertising and registrar referral links never affect the factual data, which is drawn from the authoritative sources above.

Methodology — frequently asked questions

Where does tldlist.us get its TLD data?
The list of delegated TLDs and their operating registries comes from the IANA root zone database, the authoritative record maintained by IANA on behalf of ICANN. TLD types and restrictions are based on ICANN and registry policy; example sites and indicative prices are compiled from public registrar information.
How are the TLD prices on tldlist.us calculated?
Prices are indicative annual figures in US dollars representing a typical standard rate at mainstream registrars, not a promotional first-year discount. They are review-checked and refreshed regularly. Actual prices vary by registrar, currency and promotion, so always confirm the renewal price before buying.

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