Domain availability checker

Check whether a name is registered at the registry, across endings or a whole list at once.

Fill in the form to see the result

What this is

This domain availability checker reads only one thing: whether the registry that runs an ending has a registration record for a name right now, answered the way RDAP (RFC 9083) actually answers it — a 404 means no record exists, nothing more.

A registry keeps the authoritative record of every name registered under its ending — one registry for .com, a different one for .io, and so on. Asking it directly through RDAP is the only way to know, rather than guess from a parked page or a registrar’s storefront, whether a name has a registration record at all.

Not registered is a narrower claim than available to buy. A name can be free of any registration record and still be a premium name priced far above a normal registration, reserved by the registry itself, or blocked outright by a policy the registry enforces before any registrar ever sees an order for it.

How to read the result

Each row is one name and the registry’s own answer for it: registered, with the registrar if the answer carries one, or not registered at the registry, which is the 404 RDAP gives when no record exists. Nothing else about pricing or policy is read.

A green result lists names with no registration record. Before assuming any of them can be bought, check it at an actual registrar, because a premium or reserved name shows exactly the same "not registered" answer here and is still not something a normal order will get you.

Common mistakes

Treating "not registered" as "I can buy it" — The registry only answers whether a registration record exists. A registrar’s own pricing, a premium listing and a reservation policy all sit on top of that answer and this tool cannot see any of them.
Only checking .com — Checking one ending and stopping there misses that the same name is free, taken or premium at a dozen other endings for completely unrelated reasons; each registry decides for its own ending alone.
Assuming a taken name stays taken — A registration that is not renewed moves through an expiry and redemption period and can become unregistered again months later, so a name checked once and never again can quietly change state.
Pasting more than the registry can be asked about at once — Checking dozens of names at once by hand invites typos that turn a real check into a check of a name nobody asked about; a short list checked carefully beats a long one checked carelessly.

Questions

Does "not registered at the registry" mean I can buy the domain?

No. It means the registry has no registration record for that name right now. A premium name, a reserved name or one a registrar refuses to sell for policy reasons can show exactly this answer and still not be purchasable through a normal order.

Why does the same name show differently for .com and .io?

Each ending is run by its own registry with its own records, so a name can have a registration under one ending and none under another; there is no shared ledger across endings to keep them consistent with each other.

How many names can I check at once?

Up to 20: either one bare name checked across every ending you choose, or a pasted list of up to 20 full domains, one per line, each already carrying its own ending.

Can a domain become available again after it is registered?

Yes. A registration that lapses moves through an expiry grace period and then a redemption period before the registry finally releases it, after which it can show as not registered here again.

Resell domain registration across the endings your customers ask for, at your own price.

Get started

API example

Example request

curl -X POST https://163-123-236-68.sslip.io/api/tools/domain-availability \
  -H "Content-Type: application/json" \
  -d '{"query":"widgetco","endings":["com","net","org"]}'

Example response

{
  "tool": "domain-availability",
  "input": {
    "query": "widgetco",
    "endings": [
      "com",
      "net",
      "org"
    ]
  },
  "result": {
    "verdict": {
      "tone": "success",
      "headline": "2 of 3 not registered at the registry",
      "summary": "That means no registration record exists for them yet, not that any registrar will sell them to you."
    },
    "findings": [
      {
        "id": "already-registered",
        "severity": "info",
        "title": "1 name already registered",
        "detail": "widgetco.com is registered at the registry already, so a fresh registration will be refused no matter what any storefront shows."
      },
      {
        "id": "not-registered-at-registry",
        "severity": "pass",
        "title": "2 names not registered at the registry",
        "detail": "widgetco.net, widgetco.org have no registration record at the registry that runs their ending (RFC 9083's RDAP answer, read as a 404). That is not the same as being orderable: a premium, reserved or blocked name can give exactly this answer and still not be something any registrar will sell. This reads only the registry's own answer, nothing a storefront decides."
      }
    ],
    "parts": [
      {
        "kind": "table",
        "title": "The registry’s own answer, one row per name",
        "columns": [
          "Name",
          "Registry says",
          "Registrar"
        ],
        "rows": [
          [
            "widgetco.com",
            "Registered at the registry",
            "Example Registrar, Inc."
          ],
          [
            "widgetco.net",
            "Not registered at the registry",
            "—"
          ],
          [
            "widgetco.org",
            "Not registered at the registry",
            "—"
          ]
        ],
        "mono": [
          0
        ],
        "note": "Not registered at the registry is not the same as available to buy."
      }
    ],
    "lookups": [
      {
        "label": "RDAP for widgetco.com",
        "value": "registered via Example Registrar, Inc."
      },
      {
        "label": "RDAP for widgetco.net",
        "value": "no registration found (404)"
      },
      {
        "label": "RDAP for widgetco.org",
        "value": "no registration found (404)"
      }
    ],
    "limits": [
      "This reads only whether the registry itself holds a registration record. It cannot see a registrar’s price, a premium listing, a reserved or blocked list, or any policy that would stop a purchase even though the registry shows nothing registered.",
      "A name that looks unregistered here can still be unbuyable everywhere, and a name shown as registered can become unregistered again once its registration lapses and its redemption period ends."
    ]
  }
}

Related tools

DNS and domains

WHOIS / RDAP lookup

See a domain’s registrar, its dates and every status code explained, read from RDAP rather than old WHOIS.