Bulk Domain Lookup — WHOIS (RDAP), DNS, Expiry & Availability

Look up a list of domains in one run and get one clean row per domain: whether it is registered, the registrar, creation and expiry dates, days until expiry, domain statuses, name servers and DNSSEC, plus live DNS records (A, AAAA, MX, NS, TXT, CNAME, SOA). Registration data comes from RDAP, the official successor to WHOIS, using the IANA list of registry servers. DNS records are read straight from DNS. Export as JSON, CSV or Excel, or call it as an API.

No proxies, login or API keys are needed.

What you can do with it

• Watch a domain portfolio. Schedule a weekly run and flag domains with few daysUntilExpiry, or changed name servers and statuses.
• Check a list of names for availability before you spend time on them, then confirm the shortlist with a registrar.
• Enrich company lists. Add registrar, domain age and hasMailServer to a sales or SEO list, and see which domains use Google, Microsoft or another mail provider from the MX records.
• Security and brand checks. Review name servers, SPF/TXT records and DNSSEC across the domains you are responsible for, or look at look-alike domains.

Input

{
    "domains": ["google.com", "https://www.wikipedia.org/wiki/Domain", "bbc.co.uk", "example.io"],
    "includeWhois": true,
    "includeDns": true,
    "dnsRecordTypes": ["A", "MX", "NS", "TXT"]
}

• domains — bare domains or full URLs. The scheme, path, port and www. are removed and the name is lowercased. Subdomains are reduced to the registrable domain, so blog.example.co.uk becomes example.co.uk. Duplicates are looked up once.
• includeWhois — registration data via RDAP (default on)
• includeDns — DNS records (default on)
• dnsRecordTypes — which record types to look up (default all seven)

Input validation

The run stops before any lookup if the input is invalid, and the error names the field:

• domains is required: a list of strings, up to 1,000 entries, each at most 2,048 characters. An entry that is not a domain (a stray line in a pasted list) is skipped and listed under invalid in SUMMARY. If none of the entries is a domain, the run fails up front.
• includeWhois and includeDns must be true or false, and at least one of them must be on.
• dnsRecordTypes must be a list drawn from A, AAAA, MX, NS, TXT, CNAME and SOA (any case). An unknown type fails the run; it is no longer dropped silently. An empty list means all seven.

Redaction in TXT records

TXT records are free text, and some carry an owner's email or phone number (for example a DMARC rua=mailto: address). Each TXT value is passed through the shared redaction module (src/redact.js), which replaces emails and phone numbers with [redacted]. The trade-offs:

• Role addresses such as DMARC report mailboxes are redacted too, because the module can't tell a role address from a personal one.
• Verification tokens and UUIDs (anything written as key=value, and standard UUIDs) are shielded from the phone-number rule. Without this, a live docusign= UUID was partly redacted.
• soa.hostmaster is not changed. It is the zone's technical contact written in DNS form (for example hostmaster.bbc.co.uk). For a small personal domain it can identify the owner.

Output

One item per domain. Every item has the same fields; ones that do not apply are null or an empty list.

{
    "domain": "wikipedia.org",
    "tld": "org",
    "registered": true,
    "available": false,
    "registrarName": "MarkMonitor Inc.",
    "registrarIanaId": "292",
    "createdDate": "2001-01-13T00:12:14.754Z",
    "updatedDate": "2026-08-12T08:47:19.410Z",
    "expiryDate": "2027-01-13T00:12:14.000Z",
    "daysUntilExpiry": 99,
    "statuses": ["client delete prohibited", "client transfer prohibited", "client update prohibited"],
    "nameServers": ["ns0.wikimedia.org", "ns1.wikimedia.org", "ns2.wikimedia.org"],
    "dnssecSigned": false,
    "rdapServer": "https://rdap.publicinterestregistry.org/rdap/",
    "rdapStatus": "ok",
    "a": ["198.35.26.224"],
    "aaaa": ["2620:0:863:ed1a::1"],
    "mx": [{ "exchange": "mx-in1001.wikimedia.org", "priority": 10 }, { "exchange": "mx-in2001.wikimedia.org", "priority": 10 }],
    "ns": ["ns0.wikimedia.org", "ns2.wikimedia.org", "ns1.wikimedia.org"],
    "txt": ["v=spf1 include:_cidrs.wikimedia.org ~all", "google-site-verification=AMHkgs-4ViEvIJf5znZle-BSE2EPNFqM1nDJGRyn2qk"],
    "cname": null,
    "soa": { "nsname": "ns0.wikimedia.org", "hostmaster": "hostmaster.wikimedia.org", "serial": 2026060420, "refresh": 43200, "retry": 7200, "expire": 1209600, "minttl": 3600 },
    "hasMailServer": true,
    "error": null
}

rdapStatus is ok, not_registered, unsupported (the TLD has no RDAP server), failed or skipped. A SUMMARY record in the key-value store gives the number of domains and how many were registered, available, unsupported and failed.

Pricing

You pay per result returned.

Limits worth knowing

• Availability is an inference. available: true means the registry's RDAP server answered "not found" for that name. Reserved, premium, blocked or recently dropped names can still be unavailable to register. Confirm with a registrar before you buy.
• Some TLDs have no RDAP. Several country-code TLDs (checked in this build: .io, .de and .nz) are not in the IANA list. For these, registered and available are null and rdapStatus is unsupported; DNS records are still returned. Nothing is guessed from DNS.
• Contact details are deliberately not included. Registrant, admin and technical contact names, emails, phone numbers and addresses are never output, even where a registry returns them. Registrar name and IANA ID are included. Many registries redact this data anyway.
• Subdomain handling is simple. The registrable domain is found with a built-in list of common two-part suffixes such as co.uk, com.au and co.nz, not the full Public Suffix List. Rare suffixes outside that list may be cut one label too short.
• Registry detail varies. Some registries leave out dates, the registrar IANA ID or DNSSEC data. Those fields are then null. The registry's own name servers (nameServers) can differ from the live NS records (ns).
• DNS is a live snapshot from the resolver on the machine that runs the Actor. A missing record is returned as an empty list. If a resolver fails or times out, the reason is in error.
• RDAP servers rate-limit. The Actor works on about ten domains at a time, sends one request at a time to any one RDAP server, and retries with a pause when a server asks it to slow down. Very large lists of domains under the same TLD therefore take longer.

Questions and requests

Open an issue on the Issues tab and it will be looked at quickly.