Bulk domain availability checker: up to 500 domains from the registries
A bulk domain availability checker looks up many domain names at once and says which are already registered. Paste up to 100 domains, or 500 after a Google sign-in, or bare names to try across .com, .io, .ai and other TLDs, and press Check availability. Each name is checked against its TLD registry's RDAP server and DNS: no registry record and no nameservers means likely available, and TLDs without RDAP show unknown instead of a guess. Likely available is not a guarantee; the registry is the source of truth, and your registrar confirms before you buy.
Sample result
acme-shop.example looks available. Its registry has no record of it.
- Domain
- acme-shop.example
- Basis
- No RDAP record, no nameservers
- Registry
- rdap.registry.example
What this means for you
Worth grabbing at a registrar soon; the registrar confirms it's free before you pay.
- 100 domains a run, 500 when signed in
- Asks each TLD's own RDAP registry
- Cross-checks DNS delegation
- Registered names show registrar and expiry
- RDAP
- Bulk
- No signup
By SimpleVerifier Team · Last updated
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How do I check if many domains are available?
- Paste up to 100 domains, one per line (500 when signed in with Google), such as acme-mail.com. Bare names like acmehq are tried with every TLD you tick, .com by default, and each pairing counts toward the limit.
- Press Check availability. Results arrive in batches of 20 as each registry answers.
- Read the status of each: Likely available, Registered (with registrar and expiry date where the registry shares them) or Unknown.
- Tick Show only likely available, download the CSV, and confirm the ones you want at a registrar, which also shows the price.
Example
- You enter
- Two domains pasted one per line:
acme-shop.exampleandyourcompany.example. - You get
acme-shop.examplecomes back Likely available, because its registry's RDAP server has no record and the name has no nameservers.yourcompany.examplecomes back Registered, with registrar and expiry where the registry shares them. Download the table as CSV.- Limits
- Up to 100 domains a run without an account and 500 when signed in with Google, counted after bare names are paired with each ticked TLD. TLDs without RDAP show Unknown, never available.
How do I check domain availability in bulk?
Paste the list and press Check availability. For each name, the checker finds the registry for its TLD in IANA's RDAP bootstrap file, the method set out in RFC 9224, asks that registry for the domain, and checks whether the name has nameservers in DNS. Up to 100 domains a run without an account, and up to 500 when you sign in with Google.
Registrar search pages usually check one name at a time, or suggest alternatives they want to sell. Asking the registries directly gives the registration record itself: the registrar holding the name and when it expires, which tells you when a taken name might come back.
What does likely available mean?
It means the registry has no record of the name and DNS has no nameservers for it, the two public signals of an unregistered domain. It's "likely" because a registry can hold names back without a record: premium names sold at a higher price, reserved names and blocked trademarks can look free and still be unavailable or expensive. The registrar's checkout is the final word.
Registered means the registry returned a record, or DNS shows the name delegated even if the registry didn't answer. Unknown means we couldn't confirm either way, and we never show those as available.
Why are some domains unknown?
Because their registry publishes no RDAP service. Several country-code TLDs, including .io, .co, .me and .de, aren't in IANA's RDAP bootstrap, so there's no standard way to ask them. For those, a name with nameservers is shown as registered, which DNS proves, and a name without them is unknown: it may be free or registered but parked without DNS.
Some redirect services answer "not found" for every name in such TLDs, which would show taken domains as available. This checker doesn't use them. A registry that is slow or rate-limiting also gives unknown; run those names again a minute later.
How long before a domain becomes available?
For generic TLDs, not on the expiry date shown here. The registrar can hold an expired name for a while before deleting it, and once deleted, ICANN's Expired Registration Recovery Policy requires most gTLD registries to offer a 30-day Redemption Grace Period in which the previous owner can still restore it. Only after that is the name released, and many expired names are renewed or sold at auction before they get there.
Country-code TLDs set their own rules, so check the registry's policy for those.
How is this different from a registrar's bulk search?
| This checker | A registrar's bulk search | |
|---|---|---|
| Source | Each TLD registry's RDAP + DNS | The registrar's own availability API |
| Prices | No | Yes |
| Expiry and registrar of taken names | Yes, where the registry shares them | Usually not |
| TLDs without RDAP | Unknown, never guessed | Covered if the registrar sells them |
| Account needed | No | Often |
Who uses this tool, and for what?
- Cold emailers
- Shortlist secondary sending domains from a list of variations of your brand before buying them.
- Founders
- Test a shortlist of product names across .com, .io and .ai in one run.
- Agencies
- Check which client brand variations are still unregistered, for defensive registration or new campaigns.
- Domain investors
- See registrar and expiry dates for taken names in a list, to know which might come back.
What can’t this tool tell you?
- Likely available isn't a guarantee: premium, reserved and blocked names can look free. The registrar confirms.
- TLDs whose registries publish no RDAP, such as .io, .co, .me and .de, show unknown unless DNS proves the name is registered.
- Registration details are the registry's; some registries don't share expiry dates or registrars.
- No prices: RDAP doesn't publish them.
- Up to 100 domains a run without an account and 500 signed in, a few at a time, to stay within what the registries allow.
Common questions
- What is a bulk domain search?
- Checking many domain names in one go instead of one at a time. Paste a list, or names to try across several TLDs, and get the status of each.
- How do I check domain availability?
- Look the name up in the registry's RDAP service or at a registrar. This checker asks the registry over RDAP and checks DNS, and a registrar confirms availability and price before you buy.
- Is this bulk domain checker free?
- Yes. It checks up to 100 domains a run with no account, and up to 500 a run when you sign in with Google, with no card. The registries' RDAP services are public.
- Can I check domains without a registrar seeing my searches?
- This checker asks the TLD registries, not registrars, so your list isn't sent to a registrar's search page. It does pass through our server, which doesn't keep it.
- Does likely available mean I can register the domain?
- Usually, but it isn't guaranteed. Likely available means the registry has no record of the name and DNS has no nameservers for it. Reserved, blocked and premium names can look the same, so the registry is the source of truth and your registrar's checkout shows whether you can buy it and at what price.
- Which TLDs can I check?
- Any TLD you type, such as acme.co.uk or acme.xyz. Bare names without a TLD are tried with the ones you tick: .com, .net, .org, .io, .co, .ai, .app and .dev. TLDs whose registry runs no RDAP service, such as .io, .co, .me and .de, show unknown unless DNS proves the name is registered.
- Why does a domain show as likely available but cost more at the registrar?
- It's probably a premium name: the registry has it unregistered but prices it higher. RDAP doesn't publish prices, so the registrar's search is where you'll see it.
- Does domain extension matter?
- Any TLD can be set up with SPF, DKIM and DMARC. For outreach, many senders pick .com or a country code their recipients know, because people judge an unfamiliar domain before they open the email.
Sources
Authentication and capacity are half of deliverability.
The other half is who you send to. Every hard bounce counts against the domain and inboxes you are sending from, and nothing in DNS can tell you which addresses on your list are dead.
- Bulk verification with real SMTP mailbox checks
- Hard bounces removed before a send, not discovered after
- Catch-all, disposable and role detection on every row
One plan, cancel anytime, no contract. Sign in with Google and your first 100 email checks are free, no card. The free tools stay free either way.