A bulk domain availability checker takes a list of names and asks the registry about each one. You get one of three answers per name: available (no registration exists), registered (someone holds it), or dropping (it has expired and is in redemption or pending delete). The answer is only as good as your reading of it, though. "Available" is not a promise you can register the name at the standard price, and "registered" does not always mean you should cross it off.
How a bulk domain availability check works
Every generic extension and many country-code extensions now publish registration data over RDAP, the protocol ICANN describes as the replacement for WHOIS. Since 28 January 2025, gTLD registries and registrars are no longer required to run WHOIS at all, except for a few extensions such as .com. A bulk checker sends one RDAP request per name to the right registry server and reads the reply:
- A record comes back: the name is registered. The reply carries its dates, registrar and status codes.
- Nothing comes back: under RFC 7480, the IETF standard for RDAP over HTTP, a server with no data for the query answers with a 404 "Not Found". To a bulk checker that means available.
- A record with
redemptionPeriodorpendingDelete: the name is registered on paper but on its way out. A good checker reports this as dropping rather than lumping it in with "registered".
The free bulk domain availability checker on this site works this way and sorts each name into those three states. It takes 5 names at a time as a guest, 20 with a free account and 50 on Pro.
Preparing the list for a bulk domain search
Most of the work is in the list, not the lookup.
- One name per line. Strip
http://,www.and trailing paths from anything copied out of a spreadsheet. - Bare names or full domains. A full domain (
examplecoffee.com) is checked once. A bare name (examplecoffee) is tried across several extensions; on this site's tool, eight. Use bare names when brainstorming, full domains when working from a drop list. - Remove duplicates and split into batches that fit the limit. For hundreds of names, the expired domain API guide covers doing it in a script.
What "available" means, and why it is not a guarantee
An available result means the registry holds no registration for that name. It does not mean any registrar will sell it to you at the normal price. Three things can sit behind an empty answer:
- Reserved or blocked names. ICANN's registry agreement lets a registry withhold certain names, and some are reserved by policy (ICANN publishes the categories on its reserved names page). A reserved name has no registration, so a lookup finds nothing, yet you cannot buy it.
- Premium pricing. Some registries price selected names above the standard fee. The name is genuinely free, but the checkout shows a higher price.
- Timing. A name released in today's drop can be caught within moments. An available result is a snapshot of when you ran the check.
So treat "available" as a shortlist. A registrar's search shows the real price, or refuses the name.
What "registered" means: check before you give up
A registered result tells you someone holds the name today. Before you discard it, look at two things in the record (the WHOIS lookup shows both):
- The expiry date. A name expiring soon, with no renewal in sight, may come back to market. A name renewed for years ahead will not.
- The status codes.
autoRenewPeriodmeans the name has expired and sits in the registrar's grace period, where many registrars run an expiry auction. Ordinary transfer and update locks just mean the owner protected it. The guide to domain status codes explains each one.
If the name matters to you and is not expiring, the other route is buying it from the owner. A for-sale page or marketplace nameservers usually signal the name is on offer.
What "dropping" means
Dropping means the name has passed its renewal window. In redemptionPeriod (30 days for gTLDs), only the previous owner can restore it. In pendingDelete (5 days), nobody can renew, restore or register it; then the registry deletes it and it is released first come, first served.
For .com and .net, the release happens in the daily drop at around 12:00 UTC, on the sixth day after the name entered pending delete. The drop date calculator works this out from the registry record. From there, your choices are a backorder with a drop-catching service, or a manual registration attempt if competition looks thin. The article on pending delete domains covers both.
Why bulk domain checkers disagree
Run the same list through two tools and you may get different answers. The usual reasons:
| Cause | What happens | What to do |
|---|---|---|
| Registry data vs registrar search | A registry lookup only knows whether a registration exists; a registrar search also applies reserved lists and prices | Confirm "available" names at a registrar |
| Caching | Some tools store results for hours, so a name that dropped or was caught since then shows the old state | Prefer tools that query live; rerun close to purchase |
| Rate limits | RFC 7480 lets a server answer 429 "Too Many Requests" and asks clients to slow down | A tool that ignores 429 may report errors as "available"; retry slowly |
| Dropping not separated | Some tools label every existing record "taken", including names days from release | Look at the status code yourself |
The rate-limit row causes the real mistakes: a refused request read as "no record" is false availability. When a result looks too good, look the name up on its own.
Extensions you cannot check over RDAP
Not every country-code registry runs an RDAP server. At the time of writing, .com.tr, .se, .nu, .it and .es cannot be looked up this way, so a registry-based bulk checker will skip them or return an error. For those, use the registry's own lookup page or a registrar's search, one name at a time if necessary. Rules after expiry differ by country too, so a "dropping" state may not exist for them at all.
Worked example: sorting a list in one pass
Say you check ten names from a drop list and a brainstorm in one pass:
- Available (3 names). Two show the standard price at a registrar; you register the better one. The third is premium at checkout, so you skip it.
- Registered (4 names). One shows
autoRenewPeriod, so you watch for an expiry auction. Two are renewed years ahead and parked with a for-sale page; you note them as possible purchases. The last is an active business site. - Dropping (3 names). All are in
pendingDelete. The drop date calculator shows two release on the same day. You backorder the stronger one and plan a manual attempt on the other.
Before money changes hands on any of them, run the full report in the domain checker: availability says nothing about spam history, blacklists or whether the backlinks are worth having. If you would rather start from names that already passed those checks, the live list of expired domains on hunter.domains is filtered and scored before anything is shown, and the PendingDelete list shows names that are days from release.
Frequently asked questions
Is a bulk domain availability check accurate?
It is accurate about whether the registry holds a registration at the moment of the query. It cannot see reserved lists, premium prices or a name caught seconds later. Confirm available results at a registrar.
Why does a domain show as available but cannot be registered?
Usually the name is reserved or blocked by the registry, or it is a premium name priced above the standard fee. A checker that misreads a rate-limit error can also report a false "available".
How many domains can I check at once?
It depends on the tool. Here, 5 names per batch as a guest, 20 with a free account and 50 on Pro. For thousands of names, a script against the registries' RDAP servers works, as long as it respects their rate limits.
Can I check expired domains in bulk?
Yes. A checker that reads status codes shows which names are in redemption or pending delete and so will be released soon. For the full timeline of each name, pair it with the domain expiration lookup and the drop date calculator.
