Check domain extensions for one name
Type the left-hand part only (no dot). We build the full domains, check DNS, then RDAP where registries support it. Always confirm at a registrar before you buy.
How this extension check works
Sometimes you already picked the brandable left-hand piece (for example northstar) and you only want to see how it reads across a basket of extensions. This page builds those full domains for you, then runs the same DNS and RDAP pipeline as the bulk checker.
Use the toggle at the top of the tool to scan either 50 or
100 curated, single-part TLDs. The list favors widely used
generic and country-code extensions people actually register. It intentionally avoids multi-part public
suffixes like co.uk because our RDAP routing follows one label at a time. If you need those shapes, paste full
domains into the bulk checker instead.
DNS first, RDAP second
We start with a DNS-over-HTTPS lookup for each generated name. If public DNS already shows active records, we stop there and mark the row taken. If DNS looks empty, we move on to RDAP so we can catch domains that are registered but not yet pointed at a website.
RDAP calls run in small batches because registry servers are slower than resolvers. If a TLD does not expose RDAP in the public bootstrap list, you will see Unsupported. If the request fails or gets throttled, you will see Error. Neither label means the domain is safe to register without a manual registrar check.
When to pick 50 versus 100 extensions
Start with 50 when you want a lighter pass focused on the most common endings. Switch to 100 when you are doing a wider pass before you commit to a shortlist. Changing the toggle clears the current grid so you always know which list produced the numbers on screen.
After you find a winner
Use the row actions to open the domain name appraisal tool or jump straight to a registrar search. Appraisal is a separate model: it estimates structural value, not legal clearance or renewal price.
Note: We do not store your name or the generated list. Availability can change between refreshes. If a string matters for a trademark, a funding deck, or a product launch, confirm it again at your registrar and run a proper legal screen outside this site.