Free Domain & DNS Tools
Instant domain research tools — WHOIS registration details, availability checks, and full DNS record lookups. Powered by open standards, completely free.
Pick a Tool
All tools run in your browser — no sign-up, no API keys, no limits beyond fair use.
WHOIS Lookup
Look up registration details for any domain — registrar, creation date, expiry, name servers, and registrant info.
Domain Availability
Find out instantly if a domain name is available to register. Search for the perfect name for your next project.
DNS Lookup
Query any DNS record type — A, AAAA, MX, NS, TXT, CNAME, SOA — from the global resolver network. Instant results.
More Tools
SSL certificate checker, IP geolocation, reverse DNS, HTTP header inspector, and more are in development.
Why Use HostRainbow Tools?
We built these tools to help you research domains and diagnose DNS issues quickly — the same tools our support team uses every day.
No Registration
Use every tool instantly with no account or email address required.
Authoritative Data
Data is fetched live from authoritative domain registries and the global DNS resolver network.
Private
Lookups go directly from your browser to the source — we don't log your queries.
Fair use: These tools are provided for legitimate domain research and network diagnostics only. Automated scraping, bulk enumeration, and use in connection with spam, phishing, or abuse investigations against third parties is prohibited and may result in access being blocked. Acceptable Use Policy.