Methodology

How dot.bi collects, labels and refreshes what it shows. If a value is missing, it is because no source provided it. dot.bi never guesses.

Vocabulary rules

• First observed is the first time dot.bi saw a domain, from any source (a visitor lookup, a seed list, a certificate log). It is not a registration date. A ten-year-old domain can be observed today.
• Created, expires and statuses come from the registry's RDAP record and are shown only when that record was actually fetched.
• First capture is the Wayback Machine's earliest archived snapshot, a proxy for age, labelled as such.
• No DNS means no nameservers answered. It never means “available”. dot.bi does not list expired, pending-delete or available domains, because no free, legally usable source for that exists.
• Every block on a profile states its source and the time of observation, and whether the value is live or cached.

What each section means

Registration

Fetched from the registry's RDAP service (routed with IANA's bootstrap file), then from the registrar's RDAP link for thin registries such as .com. One query per human request, cached up to 7 days. Registrant contact fields are never displayed or indexed. dot.bi does not run bulk RDAP queries.

DNS

Live resolution of A, AAAA, NS, MX, TXT, CAA and SOA records through dot.bi's own resolver at the time shown.

Hosting

The first address record is mapped to its network (ASN) with Team Cymru's public DNS service. Provider names are friendly labels for well-known networks; the country is the network's registration country, not the server's physical location.

Web

One fetch of the home page over HTTPS (then HTTP), following up to five redirects, reading at most 256 KB, identified as dotbi-probe with a link to the opt-out page. Technologies are detected from explicit signals (paths, headers, meta generator); each rule is simple and may miss or misread a site.

Email

SPF from the apex TXT record, DMARC from _dmarc, DKIM by trying a short list of common selectors (so “not found” means none of those selectors answered, not that DKIM is absent). The verdict is: well protected (SPF and DMARC reject), protected (quarantine), monitoring only (p=none), SPF only, unprotected (neither), no mail (no MX).

Age

Two small Wayback Machine CDX queries: the earliest successful capture and the number of distinct years with captures.

Name analysis

The second-level label is matched against English (370k entries, public domain) and French (320k entries, MIT) word lists, folded to ASCII. “Single” means the whole label is a word; “compound” means it splits exactly into two or three words of at least three letters.

Brandability score

A transparent heuristic on a 0–100 scale, not a valuation: start at 50; add 25 for 4–6 characters, 15 for 3 or 7–10, 0 for 11–14, subtract 15 above; subtract 15 for digits and 15 for hyphens; add 10 for high readability (no consonant cluster of four, balanced vowels) or subtract 15 for low; add 15 for a single dictionary word or 8 for a compound.

How often dot.bi observes and refreshes

• Discovery is continuous: Certificate Transparency logs are read tile by tile, and the tip is re-checked every 15 seconds. A domain appears in dot.bi one to two minutes after its certificate is logged, with dictionary words and brandability computed at once.
• Zone files are fetched once a night for every TLD whose registry grants access, then compared with the previous day: each name that entered or left the zone is recorded, counts are updated, and the per-name presence history grows. The first import of a TLD only sets its count; additions and removals start the next day. For the largest TLDs only the name and its presence dates are kept until someone looks the name up.
• Country-code TLDs without a zone are covered by the certificate feed and by weekly DNS checks of every label dot.bi already knows (at most 20 queries per second per TLD). A name that starts or stops answering DNS gets an event; neither state means “registered” or “available”.
• Newly discovered domains get DNS, hosting and email data within minutes (a batch runs every five minutes, newest first). Home-page probes and registration data are fetched when someone opens the profile.
• A profile is rebuilt when someone opens it and it is older than 24 hours. The fast parts (DNS, hosting, email, name) are computed while you wait, about a second; the slow parts (registration data, home-page probe, archive, other TLDs) finish in the background and the page refreshes itself. Registration data keeps a 7-day cache unless you press Refresh and it is older than a day.
• Lists and statistics are recomputed every hour and say which run they describe.

History

Each observation is stored with its timestamp and source. When a value changes between two observations (nameservers, IP, mail servers, registrar, status, page title, HTTP status, DMARC policy), dot.bi records an event. History starts the day dot.bi first observed the domain; nothing earlier is invented.

Limits

• New lookups are limited per network (20 per minute) to keep third-party services within polite use.
• Statistics describe dot.bi's dataset, which starts on 2026-10-13 and grows daily; they are not a census of the DNS.