WhoisXML API Domain Availability
Free trialLiveLast verified 29 Sept 2026
Checks whether a domain is free to register, using a fast DNS check or a slower DNS-plus-WHOIS/RDAP check.
Example request
curl -s 'https://domain-availability.whoisxmlapi.com/api/v1?apiKey=$API_KEY&domainName=google.com&credits=DA&outputFormat=JSON'
Free tier, in plain English
A free account includes 100 availability checks to try it. After that, lookups use purchased credits.
Alternatives in WHOIS & DNS
DigMyNameChecks domain availability and compares registrar prices across 50+ TLDs, no key required.FreeDomain IntelligenceWHOIS/RDAP, DNS, SSL certificate, subdomain and SPF/DMARC/DKIM data for a domain in one call.FreemiumDomainr (Fastly)Domain name suggestions and registration status (available, parked, premium, for sale) across TLDs.DomScanDomain, DNS, WHOIS/RDAP, TLS, typosquatting and brand-monitoring lookups across 1,100+ TLDs.FreemiumHackerTarget IP Tools APIASN, DNS, reverse DNS/IP, WHOIS, GeoIP, HTTP header and subnet lookups for any IP or domain as plain text.Freemium
All 9 WHOIS & DNS APIs →