Data sources & methodology

• Price source: nazhumi.com open API (endpoints /api/v1, /api/aboutapi, /api/currencies).
• Direct sources: for registrars nazhumi does not cover, we read the registrar's own public price list: Atak Domain (about every 3 days, last 2026-10-16); Atom (about every 3 days, last 2026-10-16); Blacknight (about every 3 days, last 2026-10-16); Bluehost (about every 7 days, last 2026-10-13); ClouDNS (about every 3 days, last 2026-10-16); ExonHost (about every 7 days, last 2026-10-13); HawkHost (about every 3 days, last 2026-10-15); HostAfrica (about every 3 days, last 2026-10-15); Host.al (about every 7 days, last 2026-10-13); Moniker (about every 3 days, last 2026-10-16); Nfly (about every 3 days, last 2026-10-16); NicNames (about every 7 days, last 2026-10-13); Papaki (about every 3 days, last 2026-10-16); Tencent Cloud (International) (about every 3 days, last 2026-10-16); Wix (about every 7 days, last 2026-10-13). A first collection is reviewed by a person before it is published. Each row shows its own observation date.
• Cadence: daily price snapshots; daily promo snapshots; weekly registrar/suffix discovery.
• Current page version: snapshot 2026-10-16 17:12 UTC, fx version 10, display rate version 11.
• Unified basis: all rankings and 3-year TCO use CNY-converted values at snapshot fx version (v10); originals retained per row.
• Display currency: default USD site-wide (all languages); switchable to USD/CNY/EUR/GBP/JPY/KRW at a build-frozen display rate version (v11). Conversion is a reference only (per-item error ≤ 0.00005/rate + half a display unit; 3-yr TCO ≤ 0.00015/rate + half a display unit); original quotes remain the settlement reference. GBP/KRW come from ECB reference rates cross-checked against the nazhumi anchor (≤2% gate).
• Availability: RDAP (RFC 7480); 404 = no registration record found, not a purchase guarantee.
• Retention: raw points 90 days (then daily aggregates); snapshots append-only.

WHOIS privacy information

The "Privacy" column in the extension tables draws on three kinds of evidence: a registrar's published general policy, registry rules, and per-extension lists that a few registrars publish. A conclusion that rests on a general policy alone is an inference and is marked with * in the tables; where there is no reliable evidence the cell shows "—". Each entry is listed below with a quoted excerpt and its source.

Extension technical details

• All first-party public data: the IANA Root Zone Database (type, sponsoring organisation / ccTLD manager, registry website, WHOIS, IANA registration date), the ICANN gTLD list (registry operator, delegation date, new gTLD, brand TLD, terminated agreements), the root zone file (name servers, glue addresses, DS records) and the IANA RDAP bootstrap file (RDAP server). No third-party aggregator data is used.
• Cadence: the root zone file and the ICANN list are checked weekly; IANA pages are re-checked on a daily rotation that covers every extension in about four weeks. Each group shows its own check date.
• The root zone file is used only when it passes integrity checks: it matches the published MD5, its NSEC records form a closed chain over every extension, and the ZONEMD serial matches the SOA. If a download or check fails, the last good data and its check date are kept.
• "DS record in the root zone" only says whether the root holds a DNSSEC trust anchor for the extension. It does not prove the chain validates right now, nor that every registrar lets you enable DNSSEC on your domain.
• "New gTLD" means an extension from ICANN's 2012 new gTLD program (entries with an application ID in ICANN's list); entries without one are not classified. The date an extension was delegated to the root zone is not the date public registration opened.
• Name server addresses are the glue records in the root zone file; an address type that is not listed is one the root zone does not give, not one the server lacks.
• Fields a source does not provide are not shown, and are never filled with "unknown".

How extension write-ups are written and checked

• The "About" section on an extension page is written by hand. Every sentence maps to a quoted source excerpt and says whose statement it is ("according to the registry", "IANA records …"). Sources are mainly primary: the registry's site, IANA and ICANN.
• Nothing without a source goes in: no "most popular" or "best for" judgements, and no paraphrase beyond what the source says. If we cannot find the eligibility rules for an extension, the "Who can register" row is not shown — which does not mean there are no restrictions.
• Secondary sources such as Wikipedia are used only as supplementary references for background sentences in the write-up (for example, which territory a country-code extension belongs to); such sentences say "according to Wikipedia" and the source is labelled separately; eligibility, local-presence and launch-date facts use primary sources only.
• Each write-up is checked against its sources by the site editor before it is published, and the review date is shown on the page. Sources change, so we re-check them and update the write-ups.

How we record events

• "Recorded events" on extension and registrar pages only list sourced facts: changes to prices or contract terms, changes of operator or ownership, shutdowns, sovereignty or jurisdiction arrangements, security incidents and compliance actions. We go back ten years for extensions (shown on extension pages) and five years for registrars (shown on registrar pages). Registrars we have affiliate links with are held to the same standard as all others.
• Every event has at least one primary source (an announcement by the party involved, or a document from the registry, ICANN, a government or a regulator). Press reports only supplement it. Third-party statistics are cited only with their period and sample limits, and never as a verdict on a whole extension.
• Each sentence says whose statement it is ("ICANN says", "a UK government note says") and only reports what the source says. For investigations, arbitration or court cases we give the procedural status and take no side. We do not score, rank or call extensions or registrars "safe" or "unsafe".
• The site editor checks every event against its sources before it is published and sets a re-review date; events past that date cannot be published. Corrections are recorded under the event. An event not listed here may still have happened.