Inspect domains, networks and URLs — DNS, WHOIS, certificates and more.
Look up a domain's DNS records — A, AAAA, CNAME, MX, NS, TXT, SOA and CAA.
Look up a domain's registration data — registrar, dates, nameservers and status — via RDAP.
Inspect a domain's TLS certificate — validity, issuer, subject/SANs and protocol version.
Fetches a URL and evaluates the response's security headers — CSP, HSTS, X-Frame-Options and more.
Paste the JSON an API should return and get a real URL to test your frontend against.
Extracts and decodes URL parameters — paste the whole URL or just the query string.
Builds and encodes a query string from editable key/value pairs.
Look up registration, routing, cloud, reverse DNS and approximate location data for an IP.
Calculates network, mask and hosts for an IPv4/IPv6 block, plus VLSM and route aggregation.
Checks if a URL is up from our server — is it down for everyone or just you?