Bulk domain availability checker

When you are naming a company, clearing a long shortlist, or stress-testing a portfolio slice, you need a fast read on which full domain strings are probably open. This tool takes a pasted list and returns one row per name using the same two-step flow every time: public DNS first, then RDAP for anything that still looks available at the DNS layer.

You can paste up to 500 domains per scan. Mix extensions freely. Full URLs and a leading www. are fine. We remove duplicates, normalize casing, and strip obvious junk before the requests run.

Step one: what the DNS pass is checking

We query live DNS through DNS-over-HTTPS. If the answer includes common active record types (for example A, AAAA, MX, or NS), we treat the domain as taken for practical purposes because something is already published on the public DNS.

If the resolver returns NXDOMAIN, the public DNS tree does not carry a normal zone for that exact name. That is a strong hint, but it is still not the same as a registrar cart. A domain can be registered and still look quiet in DNS, which is why we always add the registry pass below.

Step two: RDAP and why it matters

For every name that looked available on DNS, we call RDAP (Registration Data Access Protocol) using the public bootstrap data for DNS zones. When RDAP returns 404 for the domain object, we label the row Verified Available. When RDAP returns a record, we mark the name as taken at the registry layer even if the owner never pointed DNS anywhere yet.

RDAP is slower than DNS. We send those checks in small batches so the UI can breathe. If a registry rate-limits the request, if the network glitches, or if RDAP is not published for a given TLD, you may see Error or Unsupported. Treat those rows as inconclusive, not as proof you can register the name.

How to read the status labels

• Taken: DNS already shows active records, or RDAP found a registry object.
• Verified Available: DNS looked empty and RDAP returned no registration for that exact string.
• Verifying registry: DNS finished and the RDAP pass is still running.
• Error or Unsupported: we could not finish the registry check. Double-check at a registrar before you rely on the name.

What this checker is not

This page does not replace a registrar checkout, a trademark clearance search, a backorder queue, or a premium price quote. It also does not know about private sales, registry reserved lists, or sunrise phases for new extensions. Always confirm price, eligibility, and transfer rules at the registrar you trust.

Related tools on this site

If you already have a clean left-hand label and want to compare popular extensions in one pass, use the check domain extensions tool. When you have a shortlist of winners and want a rough resale baseline, open the domain name appraisal tool. For longer reads on naming workflows, start with the blog.

Note: We do not store your pasted list. Availability signals can change quickly. If a name matters for a launch, verify it again at your registrar before you print packaging, file trademarks, or pay for premium branding work.