Our Methodology

• Open PageRank — a free API providing a 0-10, PageRank-style authority score per domain. This is the primary signal behind DA, PA and DR.
• RDAP — the modern, standardized successor to WHOIS, used to determine domain registration/creation date where available.
• Wayback Machine (Internet Archive) — used as a fallback domain-age signal when RDAP data is redacted or unavailable (common on some ccTLDs and privacy-protected registrations).
• Live TLS/SSL check — a direct connection to the domain to verify a valid HTTPS certificate.
• Public DNS blocklists — Spamhaus DBL and SURBL, queried the standard DNS-based way, no API key required. These free public zones rate-limit or block queries from some shared/datacenter resolvers, so this signal is treated as best-effort: we specifically filter out Spamhaus's documented "query blocked" response codes so a blocked lookup is never mistaken for a real listing.
• DNS resolution — confirms the domain actually resolves (is "live") at check time.

We deliberately do not use Moz's, Ahrefs', or Semrush's proprietary APIs — this tool is built entirely on free, publicly accessible data, which is why our numbers won't exactly match those platforms.

DA starts from the Open PageRank score (0-10), scaled to a 0-100 range, then adjusted with small bonuses or penalties for domain age, valid HTTPS, and whether the domain currently resolves. If Open PageRank has no data for a domain (common for very new or low-traffic sites), we fall back to a smaller score built purely from age and technical signals, capped lower to reflect the added uncertainty.

Open PageRank only scores at the domain level — it does not provide a distinct signal per URL. Rather than fabricate false precision, PA on DAMetrics is a disclosed approximation: a small, deterministic adjustment from the domain's DA, intended to reflect the homepage. If you need true per-page authority modeling, treat PA here as directionally useful rather than exact.

DR uses the same Open PageRank signal as DA but with a different curve (a steeper exponential weighting) and a different age-bonus weighting, so it is not simply a copy of the DA number. Like DA and PA, it is our own independent estimate — not Ahrefs' DR — built to be directionally comparable across domains.

Spam Score combines, additively, up to a maximum of 17:

• Domain age under 1 year: +6. Under 2 years: +3. Under 3 years: +1.
• Each public DNS blocklist hit: +4, capped at +8 total.
• Missing or invalid HTTPS: +2.
• Domain not currently resolving: +3.
• Statistically higher-risk TLD (e.g. .xyz, .top, .click, .work): +2.

Lower is safer. This is a heuristic risk signal, not a guarantee — always use judgment alongside it for high-value decisions.

Results are cached for up to 12 hours per domain to keep the tool fast and to stay within the free API quota. Re-checking the same domain within that window returns the same cached result.

"Domain Authority" is a registered trademark of Moz, Inc. DAMetrics is an independent tool, not affiliated with, endorsed by, or connected to Moz. Our use of "DA" refers to the general, industry-standard concept of domain-level search authority, calculated with our own methodology described above.