# Bulk Domain Availability Checker

> A bulk domain checker tells you which of a list of domains are still available and which are already registered, in one pass. This one queries each registry directly over RDAP - the protocol that replaced WHOIS - so a taken domain comes back with its registrar and expiry date rather than a parked-page guess.

Source: https://rankcert.com/tools/bulk-domain-availability
Free, no signup. Updated: 2026-09-08

## How to use it

1. Paste up to 25 domains, one per line - the TLD is required, so write myproduct.com, not myproduct.
2. We ask each registry directly over RDAP, six at a time.
3. Available names sort to the top; taken ones show the registrar holding them and when the registration expires.

## Questions

### How many domains can I check at once?

Twenty-five per run. That is the point where registries start rate-limiting a single caller, and a slower tool that gets throttled is worse than a fast one that respects the limit. Run it again for the next batch.

### Is this the same as a WHOIS lookup?

It uses RDAP, the protocol ICANN mandated to replace WHOIS. RDAP returns structured JSON instead of scraped text, so registrar and expiry come back reliably rather than parsed out of free-form output.

### Does it work for every TLD?

For every TLD that publishes an RDAP service - all gTLDs and most ccTLDs. A few registries, .de among them, still do not. Those come back marked unconfirmed rather than guessed at, because a false 'available' is the one answer this tool must never give.

### Does checking a domain here risk front-running?

No. RDAP queries go to the registry, not to a registrar's search box, and nothing you type is logged against your session or sold on. Front-running has historically come from registrar search tools, not registry lookups.

### Why does a domain show as available when a registrar says it is taken?

Usually a premium or reserved name: unregistered at the registry, but withheld from general sale. RDAP reports the registration status, which is the truth about who holds it, not the sales status.

### What does the expiry date mean for a taken domain?

It is when the current registration lapses, not when the name becomes buyable. Expect a 30-day grace period plus a 30-day redemption window after that, and most owners renew. Treat it as a signal, not a date to plan around.

### Can I check availability without the TLD?

No - example.com and example.io are different registrations at different registries. List every extension you actually want, one per line.

### Is there a limit on how often I can run it?

Four bulk runs a minute from one IP. Results are cached for an hour, so re-checking the same list costs nothing.

## Related tools

- [WHOIS Lookup](https://rankcert.com/tools/whois-lookup): Look up any domain's registrar, registration date, expiry, status codes and nameservers using live RDAP registry data.
- [Domain Age Checker](https://rankcert.com/tools/domain-age-checker): Find out exactly how old a domain is, when it was registered, when it was last changed and when it expires.
- [DNS Lookup](https://rankcert.com/tools/dns-lookup): Query every common DNS record type for any domain at once, with TTLs, resolved through Cloudflare's public DNS-over-HTTPS resolver.
- [Domain Popularity Checker](https://rankcert.com/tools/domain-rating-checker): Check how popular any domain is on a 0-100 score built from the Tranco top-million ranking, with its raw rank and 30-day movement.
- [Bulk Domain Popularity](https://rankcert.com/tools/bulk-domain-rating): Score up to twenty-five domains at once against the Tranco top-million ranking and sort them, so you can triage a link prospect list in one pass.
- [Meta Tags Checker](https://rankcert.com/tools/meta-tags-checker): Check any page's title, meta description, canonical, robots and heading structure, and see the exact issues that hurt its rankings.