Domain tools
Focused, free checks for registration, DNS, web and email configuration. Each result explains what it found.
25 tools 6 categories Free, no sign-up
Registration 4 tools
Look up who a domain is registered through, when it was created, when it expires and whether it can be registered.
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RDAP / WHOIS Lookup
See a domain's registrar, status codes, key dates and nameservers from the official registry RDAP service.
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Domain Availability
Find out whether a domain is registered, likely available or cannot be checked, with the evidence behind the answer.
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Domain Age
Check when a domain was registered and how old its current registration is, based on registry RDAP data.
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Domain Expiry
See when a domain registration expires, how many days remain and whether it is on hold or pending deletion.
DNS 6 tools
Query DNS records, check nameservers and DNSSEC, compare public resolvers and inspect reverse DNS and CAA.
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DNS Lookup
Query A, AAAA, MX, TXT, NS, SOA, CAA and other records for any hostname through public DNS resolvers.
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Nameserver Checker
Review a domain's delegated nameservers: count, addresses, network diversity, IPv6 reachability and SOA.
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DNSSEC Checker
Check whether a domain is DNSSEC-signed, whether its DS and DNSKEY records match and whether it validates.
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DNS Resolver Comparison
Ask several public recursive resolvers the same DNS question and see whether their cached answers agree.
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Reverse DNS
Look up PTR records for an IP address or a domain's addresses and confirm they resolve forward again.
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CAA Checker
See which certificate authorities a domain allows to issue SSL/TLS certificates, including wildcard rules.
Web & SSL 4 tools
Test certificates, HTTPS availability, status codes, redirect chains and security headers of a website.
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SSL Checker
Inspect the certificate served on port 443: validity dates, hostname match, chain trust, protocol and key.
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HTTP Status & HTTPS Checker
Check whether a site answers over HTTPS, whether HTTP redirects to it and which status code is returned.
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Redirect Checker
Follow a URL hop by hop and see every redirect, status code and final destination, with loop detection.
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HTTP & Security Headers
View a site's response headers and review HSTS, CSP, framing, referrer policy and cookie attributes.
Email security 5 tools
Check the DNS records that route mail and protect a domain from spoofing: MX, SPF, DKIM, DMARC and more.
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MX Checker
List the mail servers for a domain in priority order and check that each one resolves to a public address.
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SPF Checker
Validate a domain's SPF record, its all qualifier and the number of DNS lookups it needs against the limit of 10.
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DMARC Checker
Read a domain's DMARC policy, reporting addresses and alignment settings, and see how strictly it is enforced.
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DKIM Checker
Look up the DKIM public key for a selector you provide and check its presence, key type and key length.
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Email Security Checker
Review a domain's complete mail posture in one pass: MX, SPF, DMARC, MTA-STS, TLS-RPT and BIMI.
Security intelligence 3 tools
Passive intelligence from public sources: certificates in Certificate Transparency logs, publicly observed hostnames and look-alike (homograph) risk.
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Certificate Transparency Search
See certificates publicly logged for a domain and its subdomains: issuers, validity dates and the names they cover.
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Passive Subdomain Finder
List hostnames publicly observed in Certificate Transparency logs and whether they still resolve — no brute force, no scanning.
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IDN Homograph Risk Analyzer
Check whether an international (Unicode or Punycode) domain name can be visually confused with another name: scripts, look-alike characters and invisible characters.
Utilities 3 tools
Helpful extras: IP network registration data, IDN conversion and a keyword-based domain name generator.
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IP Lookup
Find the IP addresses behind a host and the network registration data published by the regional registry.
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IDN Converter
Convert internationalized domain names between Unicode and Punycode (xn--) forms and spot mixed scripts.
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Domain Name Generator
Turn a few keywords into short, brandable and descriptive domain name ideas, then check any of them on demand.
No tools match your search. Try a shorter term such as “DNS” or “SSL”.