Inspect any public domain the way an attacker would: DNS records, registration data, and HTTP security headers, plus an IPv4 subnet calculator. The lookup tools send only the domain or URL you enter to public DNS, RDAP, or our own server checks; the subnet calculator runs entirely in your browser. Nothing you enter is stored.
Each tool runs a real check against the target you enter and returns actionable, plain-language results.
Query DNS records from Cloudflare and Google side by side, compare TTLs, and check DNSSEC.
See a domain's registrar, registration and expiry dates, status, and nameservers, with a domain-age phishing flag.
Grade any site's HTTP response headers from A to F with per-header explanations and remediation guidance.
Turn an IP and CIDR prefix or netmask into the full picture: network, broadcast, host range, and binary.