1 of 2 routes returned a live 4021 CURATED ROUTEdomain-availability-checker.underscoredone.com
Domain Availability Checker
Give this API up to 10 domain names and it will tell you whether each one has a registration record on file with the official registry. It uses RDAP — the modern, structured replacement for WHOIS — so there is no messy free-text parsing. Each domain comes back labeled 'registered', 'unregistered', or 'indeterminate' (when the registry does not support RDAP for that ending). Important: 'unregistered' means no record was found, which usually means the name is available — but reserved or premium names can also return no record. This API tells you registration status only; it does not tell you price, premium status, or whether a registrar will actually let you buy the name.
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resources
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data sources
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network identifiers
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registry calls / 30d
RESOURCE SAMPLE · 2 OF 2
search all →GET
https://domain-availability-checker.underscoredone.com/check
https://domain-availability-checker.underscoredone.com/check
402 quote
POST
Domain Availability Checker: POST /check
https://domain-availability-checker.underscoredone.com/check
origin reachable