Domain Registration Lookup

Ask when a domain was born and you are really asking a registry a question. The answer is a single line in a structured record: the date on which the current registration of that name was created. It is a fact, and a useful one. It is also narrower than it looks, and most of the trouble people have with domain age comes from asking that one date to carry more than it holds.

From a text service to a structured record

For decades the place to ask was WHOIS. Its roots go back to the NICNAME/WHOIS protocol, first written down in 1982 for the old ARPANET’s Network Information Center. The current specification, published in 2004, describes something very plain: a client opens a TCP connection to port 43, sends a line of text, and reads back whatever human-readable text the server chooses to send. The same document admits the protocol lacks the design features a modern one would have, naming internationalisation and strong security, and notes that it has no way at all to say which character set a reply uses.

That plainness was the problem. Every registry formatted its replies its own way, so a program that wanted the creation date had to guess at labels and layouts that changed from one server to the next. Names with characters outside basic Latin had no reliable path through the protocol. And nothing in WHOIS told a client which server was the right one to ask for a given name.

The replacement is the Registration Data Access Protocol, standardised at the IETF in 2015. RDAP keeps the simple question-and-answer shape but moves it onto HTTP and answers in JSON. A query for a domain is just an address ending in domain followed by the name. The answer is a JSON object whose members are defined by a standard, so a registration date is found in the same place whatever registry sent it.

Finding the right server is solved separately, and elegantly. IANA publishes a bootstrap file that maps top-level names to the base addresses of their RDAP servers. A client compares the name it wants against the entries label by label, from the right, and takes the longest match. On 22 October 2026 that file listed 1,203 top-level names, grouped under 592 sets of server addresses, and its own publication stamp said 30 September. Some well-known endings had no entry at all, which means the client simply cannot find an RDAP server for them; the specification says to tell the user so rather than guess.

The HTTP layer brings ordinary web conventions with it. A record that exists comes back with status 200. A name the server holds nothing about comes back as 404, which the standard defines as an empty result. A malformed question gets 400, and a server that thinks you are asking too often answers 429 and may say how long to wait. Servers are encouraged to send the header that lets a web page in a browser read their replies, with a wildcard value judged suitable for public data, which is why a lookup can run in a browser at all.

Reading the dates

The heart of the record is an array of events. Each one carries an action and a date, and the dates may lie in the future, which is how an expiry is expressed. IANA keeps the list of event names. Three matter most for age. Registration marks the start of this registration. Expiration marks the date it will leave the registry unless it is renewed. Last changed marks the most recent change to the record itself.

Those three are easy to misread. A last-changed date close to today says only that something in the record moved, and a renewal or a change of name servers is enough to move it. An expiry date a year away says nothing about whether the holder will renew. Several more event names exist: transfer, for a move between registrars; reregistration and reinstantiation, for names registered again; and one that records when the RDAP server last copied its data from the registry database, which is a fact about the server rather than about the domain.

Age itself is arithmetic on the registration date. It is worth doing in calendar terms rather than dividing days by 365, because people think in anniversaries. Month ends need a rule. A sensible one counts a whole month as reached on the same day number of the next month, or on that month’s last day when it is shorter, so a name registered on 31 January has its first monthly anniversary on 28 February, or 29 February in a leap year.

Here is a worked case you can reproduce. The built-in record on this page belongs to sample-domain.example, a name under a top-level domain reserved for documentation, so it can never be a real registration. Its registration event reads 28 February 2009 at 14:05 UTC. Set the date field to 22 October 2026 and the age reads 17 years, 7 months and 24 days. Seventeen years and seven months from 28 February 2009 lands on 28 September 2026, and from there to 22 October is 24 days. Counted as plain days, it is 6,445 days.

Status codes in plain words

Beside the dates sits a list of status values, and these are where a record says what can and cannot happen to a name. Many come from the provisioning protocol registries and registrars use to talk to each other, and a standard maps each one to its RDAP spelling. The everyday one is active, which corresponds to the provisioning status called ok: nothing pending, nothing prohibited, and the name is published in the DNS.

The prefixes carry meaning. A status that begins with client was set by the registrar that sponsors the name, and one that begins with server was set by the registry. Client transfer prohibited, for example, means requests to move the name to another registrar are refused until the registrar lifts it. A server version of the same lock can only be lifted by the registry, so it is the harder of the two to remove. Many names carry several of these at once.

Two families deserve attention when you see them. Hold statuses, from either side, mean the delegation is not published, so the name does not resolve even though it is registered. Deletion statuses describe a sequence the grace period standard spells out. A deleted name first enters a redemption period in which it can still be restored. If nobody restores it, it stays pending delete for a period the registry sets, and then it is purged and becomes available to anyone.

That sequence is why domain age has a hard edge. A purged name that is registered again is a new registration with a new registration date. The record holds no history of the earlier one, so a name that lapsed in 2015 and was taken up in 2016 reports 2016, even if the same words pointed at a well-known site for a decade before.

Redaction, privacy and the empty field

Readers used to old WHOIS output often expect a holder’s name, address and email. Many records no longer show them. Wikipedia’s account of RDAP connects this to the European data protection regulation that became enforceable in May 2018, after which a temporary policy required contact details in public replies to be redacted for privacy.

A 2024 standard made that redaction visible rather than silent. A record can carry a list named redacted, and each entry names the field and the method used. There are four redaction methods: removal, which leaves the field out; an empty value, which keeps the field but blanks it; a partial value; and a replacement value. A server may give a reason as well. When a contact appears with no name, the redacted list is where to look before concluding that the registry simply does not know.

Some records also carry a link labelled related, pointing at the registrar’s own RDAP server, which may hold more detail than the registry does. That second server is a different service with its own operator, and a careful tool shows the link for the reader to follow instead of quietly asking a further party on their behalf.

What age can and cannot tell you

Read carefully, the registration date answers one question well: how long the current registration of this exact name has existed without lapsing. That is genuinely informative. A name registered last week and used to send urgent payment requests deserves more suspicion than one held without a break since 2009, and the expiry date and status list add detail about how the holder is maintaining it.

It cannot tell you who held the name, whether the owner changed through a transfer or a sale, what the name was used for, or whether a site at that name is trustworthy today. A transfer event shows that the registrar changed, not that the holder did. Nor can it say anything about search rankings: none of the documents behind this page offers a measure linking a registration date to how a search engine treats a site, and the date is not one.

A 404 has limits too. It means the server asked has no record of that name, and the standard says no more than that. The name may be reserved, blocked by policy, or registered at a different level of the hierarchy. Only a registrar can say whether it is free to register.

So the honest use of domain age is modest. Read the dates in UTC and in your own time, read the statuses for what they permit, notice what is redacted, and treat the registration date as the start of an unbroken registration. It is a well-kept file card, nothing more.