Data Sources & Methodology

Primary sources

IANA Root Zone Database

https://www.iana.org/domains/root/db — The authoritative table of all delegated TLDs, their types, and sponsoring organisations. Updated by IANA as delegations change.

IANA Delegated TLD List

https://data.iana.org/TLD/tlds-alpha-by-domain.txt — Plain-text list of all currently delegated TLD labels. Includes a version header with date. Updated weekly.

IANA Per-TLD Delegation Records

https://www.iana.org/domains/root/db/{tld}.html — Individual pages for each TLD with registry information (WHOIS, RDAP, registration services URL), delegation history, and reference documents.

Supplemental sources (verified per-TLD)

• Registry websites — Official registration policy pages (linked from IANA's "URL for registration services").
• ICANN Registry Agreements — For gTLDs, the base agreement and any amendments.
• IANA Reports — Delegation/redelegation reports linked from per-TLD pages.

Editorial notes (registration restrictions, practical guidance) are researched from registry policies and cited explicitly. Unverified claims are marked as such.

Data processing pipeline

1. Weekly sync — Automated script fetches both IANA sources every Monday (GitHub Actions).
2. Validation — Parsers reject malformed data, duplicates, or implausibly small datasets.
3. Merge — Delegated list (source of truth for "active" TLDs) joined with Root Zone DB rows (type, manager).
4. Detail enrichment — For TLDs without a manager in the DB table, the per-TLD delegation page is fetched for WHOIS/RDAP/URL/dates.
5. Normalisation — Types mapped to canonical values; IDN labels decoded to Unicode.
6. Change detection — Added/removed TLDs logged; meta.json updated with timestamps and counts.
7. Build — Astro SSG generates static HTML for all pages from the JSON dataset.

Data quality levels

Known upstream change: IANA's 2026 page redesign

IANA redesigned both the Root Zone Database index page and the individual delegation records during 2026. Two things changed that affect this site:

1. Type taxonomy. The index page previously published six type values (generic, generic-restricted, country-code, sponsored, infrastructure, test). It now publishes three: Generic, Country Code and Special Use. As a result .gov, .edu, .museum, .aero,.post, .biz, .name and .pro now appear as Generic, and .arpa as Special Use. We follow what IANA publishes and record the change here instead of inferring the old labels.
2. Delegation status column. The index page now publishes a status per TLD (Active, Retired, Reserved, Eligible). The sync script cross-checks the count of Active rows against the authoritative delegated list and logs a warning if they diverge, but the delegated list still decides which records exist.

The parsers in src/lib/iana.ts support both the legacy and the current layouts, so a re-sync is stable regardless of which version IANA serves.

Update frequency

• Automated weekly — Every Monday ~06:30 UTC (after IANA's typical update window).
• Manual trigger — Available via GitHub Actions workflow dispatch.
• Emergency — If a major delegation change occurs, we can re-run immediately.

What we do NOT do

• We do not scrape registrar websites for pricing or availability.
• We do not use third-party domain data APIs.
• We do not guess or infer registration rules — only cite verified sources.
• We do not track domain ownership, WHOIS history, or aftermarket data.

Licensing & attribution

IANA data is public domain / freely redistributable per IANA's legal notices. Our compiled dataset, editorial content, and code are proprietary. You may link to our pages freely. For bulk data use, contact us.

Verification & corrections

If you spot an error, please contact us with the TLD, the issue, and a source. We investigate and correct within one sync cycle.