How Domain Name Now Runs an Instant Domain Availability Checker Without API Keys

A name that is not available is not a suggestion — it is a tease. So every card on Domain Name Now has to answer one question fast: can I actually buy this? The feature people call an instant domain availability checker is, for us, the thing that makes the rest of the product honest.

RDAP over WHOIS, always

WHOIS is the old protocol: plaintext, inconsistent across registries, rate-limited in opaque ways, and often scraped through fragile middlemen. RDAP — Registration Data Access Protocol — is the replacement the registries themselves publish. It returns structured JSON, handles redirects between registries cleanly, and, critically, does not require an API key. Domain Name Now hits RDAP directly for every candidate.

Chunks of eight, parallelized

Checking 40 names serially would feel like waiting for dial-up. We batch them in groups of eight, fire the batches in parallel, and stream results back as they arrive. The first batch typically lands in under a second, which is why the grid feels populated almost immediately rather than lurking behind a single slow call.

What 'available' actually means

When the RDAP server returns a 404 for a domain, the domain is unregistered. That is what we surface as 'available'. We do not surface premium listings or auction statuses yet — those cases get filtered out so a green card always means a registrar will quote you a straightforward first-year price. The tradeoff is real: we miss a few interesting premium names, and in exchange nobody gets surprised at checkout.

No caching, and why that is correct here

The pull to cache availability results is strong. It is also wrong for a product like this. A domain that was free twenty minutes ago can be registered by the time you click. Domain Name Now re-queries on every session because a false 'available' burns trust far more than an extra RDAP call costs us. The instant domain availability checker only earns the 'instant' if every answer is fresh.

What we deliberately do not do

• We do not poll registrar pricing APIs. Retail pricing is shown as indicative; the registrar confirms the real price at checkout.
• We do not scrape WHOIS through a proxy service. Every lookup goes to the authoritative RDAP endpoint.
• We do not pre-reserve or 'hold' names. The registrar owns that workflow.

The result is a checker that is cheap to run, fair to the user, and — with apologies for the claim in the name — genuinely instant.