Domain Availability Checker: bulk .com, .io, .ai and more, with registration and expiry dates

Paste your name ideas and get back, for each one, which domains are free across .com, .io, .ai, .co, .net, .org, .app, .dev or any other extension you list. Taken domains come with the registrar, the registration date, the expiry date, the registry status codes and the name servers, so you can see who owns a name, how old it is and whether it is about to drop.

Answers come straight from the registries (RDAP, with WHOIS where an extension has no RDAP, like .co). No API key, no login, no scraping of registrar storefronts.

$1 per 1,000 domains checked, platform usage included.

What you get

One row per domain:

Field	Description
domain, name, tld	The domain, its name part and its extension
status	available, registered, reserved-or-premium or unknown (see below)
isAvailable	true, false, or null when the answer is unknown
registrar	Registrar of record (taken domains)
registeredAt, expiresAt, updatedAt	Registration, expiry and last-change dates, ISO format
daysUntilExpiry	Days from the check to the expiry date
domainStatus	Registry status codes, for example client transfer prohibited, redemption period, pending delete
nameservers	Name servers of the domain
rdapServer, checkedVia	Which registry server answered, and whether by rdap, whois or dns
variationOf	The name idea this row is a variation of (only with variations on)
dnsHasRecords	Whether the domain has DNS delegation (only with the DNS check on)
note	A plain-words caveat when there is one
capturedAt	When the row was collected

The four statuses

• available: the registry says the name is not registered. Registry lookups cannot see premium pricing or registrar-side reservations (common on .ai, .app and .dev), so the row carries a note: confirm the price at checkout.
• registered: the registry holds a record for it. Dates, registrar, status codes and name servers are filled in.
• reserved-or-premium: the registry itself lists the name as reserved or blocked.
• unknown: the registry could not give a trustworthy answer (it rate-limited the run, did not answer, or the extension has no public lookup). Unknown rows are never reported as available and are not charged. The run status says which extensions and why.

Example rows (real, from a run on 2026-10-16)

{
  "domain": "sciences.io",
  "name": "sciences",
  "tld": "io",
  "status": "registered",
  "isAvailable": false,
  "registrar": "Spaceship, Inc.",
  "registeredAt": "2019-04-16T10:25:50.704Z",
  "expiresAt": "2027-04-16T10:25:50.704Z",
  "updatedAt": "2026-08-12T10:06:31.379Z",
  "daysUntilExpiry": 182,
  "domainStatus": ["client transfer prohibited"],
  "nameservers": ["ns1.afternic.com", "ns2.afternic.com"],
  "rdapServer": "https://rdap.identitydigital.services/rdap/",
  "checkedVia": "rdap",
  "variationOf": null,
  "note": null,
  "capturedAt": "2026-10-16T00:40:11.645Z"
}

{
  "domain": "harasses.ai",
  "name": "harasses",
  "tld": "ai",
  "status": "available",
  "isAvailable": true,
  "registrar": null,
  "registeredAt": null,
  "expiresAt": null,
  "updatedAt": null,
  "daysUntilExpiry": null,
  "domainStatus": [],
  "nameservers": [],
  "rdapServer": "https://rdap.identitydigital.services/rdap/",
  "checkedVia": "rdap",
  "variationOf": null,
  "note": "Not registered at the registry. Premium or reserved-for-resale pricing is not visible to registry lookups, so confirm the price at checkout.",
  "capturedAt": "2026-10-16T00:40:11.338Z"
}

Who uses this

• Founders naming a product. Drop in twenty ideas and see in one run which ones have a clean .com, .io or .ai.
• Naming and branding agencies. Check a client shortlist across every extension that matters, with the owner and expiry date of the taken ones.
• Domain investors. Spot names in redemption period or pending delete, sort taken names by daysUntilExpiry, and run big lists on a schedule.
• Marketers and growth teams. Validate campaign and microsite names in bulk before the brief goes out.

Input

Field	What it does
names	Name ideas, one per line. A bare name (acme) is checked on every extension; a full domain (acme.io) is checked as written. Spaces are closed up (my cool app becomes mycoolapp), URLs and www. are stripped, accented names become their international form
tlds	Extensions for the bare names, without the dot. Default: com, io, ai, co, net, org, app, dev. Any extension with a public registry lookup works
generateVariations	Also check get, try, use in front and app, hq, labs, ly after each name (7 extra names per idea, labelled in variationOf)
includeDnsCheck	Add dnsHasRecords, a second signal from DNS
onlyAvailable	Return only the available domains

A run takes up to 3,000 domains. Larger lists: split them over several runs.

Three ideas on four extensions

{
  "names": ["acme", "northwind", "blue fox labs"],
  "tlds": ["com", "io", "ai", "co"]
}

Find free variations only

{
  "names": ["acme", "northwind"],
  "tlds": ["com", "io"],
  "generateVariations": true,
  "onlyAvailable": true
}

Check a list of exact domains

{
  "names": ["acme.com", "acme.io", "getacme.ai"]
}

Pricing

Event	Price
Domain checked	$0.001 per domain, i.e. $1 per 1,000 domains
Run start	$0.001 per run

Store discounts apply: Bronze $0.90, Silver $0.80, Gold $0.70 per 1,000 domains.

A domain is charged when it gets a definitive answer (available, registered or reserved). Unknown rows cost nothing beyond the run start. With onlyAvailable you are charged only for the available domains you receive. Platform usage is included.

A big check: 200 names on 8 extensions (1,600 domains) took 4.5 minutes in our test and costs $1.60 at the list price.

How fast is it, and why can a big run take minutes

Registries limit how fast one address may ask: Google's .app and .dev allow about one lookup per second, Identity Digital's .io and .ai a few per second, Verisign's .com and .net and PIR's .org much more. The actor paces itself per registry, backs off when a registry says slow down, and opens extra routes when one address is limited. A mixed list of 8 extensions runs at roughly 6 domains per second overall; a list that is all .app and .dev is the slow case.

FAQ

Is "available" a guarantee I can register it? It means the registry holds no registration for the name. A domain can still be premium-priced or held back by a registrar, which registry lookups do not show. Always confirm at checkout.

Why do .co and some other extensions say checkedVia: whois? They have no public RDAP service, so the actor asks the registry's WHOIS server instead. Same answer, older format.

What does unknown mean? The registry did not give an answer this run could trust. Run those domains again later.

Do you show who owns the domain? No. Registries hide personal data, so you get the registrar and dates, not the owner's name or contact details.

Can I find domains about to expire? Yes: sort taken domains by daysUntilExpiry, and look for redemption period or pending delete in domainStatus.

Does the DNS check change the availability answer? No. The registry answer is the answer; dnsHasRecords is an extra column. DNS is only used as the answer when an extension has no public registry lookup at all, and then only to prove a domain is taken.

Related actors

• Google Trends Scraper: check that people search for the name's topic before you register it.
• Brand & News Monitor: watch the news for your new brand name.
• Google AI Overview Tracker: see whether your brand gets cited in Google's AI answers.
• Threads Scraper: check who already talks about a name on Threads.

Keywords: domain availability checker, bulk domain checker, domain name search, whois lookup, RDAP, domain expiry checker, .io domain checker, .ai domain checker, domain name generator, domain investing.