Free, fast diagnostic tools for DNS, email authentication, and network security

DNS & Network Tools Free, fast diagnostic tools for DNS, email authentication, network security, and more. DNS Tools DNS Lookup Query A, AAAA, MX, TXT, NS, SOA, CNAME, PTR, CAA, SRV, TLSA, HTTPS, MTA-STS, BIMI and more. Results come directly from authoritative nameservers. Look Up DNS Records DNS Propagation Checker Query 7 global public resolvers simultaneously to see whether your DNS changes have propagated worldwide. Check Propagation DNSSEC Checker Verify the DNSSEC chain of trust. Check DS, DNSKEY, and RRSIG records to confirm cryptographic signing is properly configured. Check DNSSEC Whois Look up structured RDAP registration data for any domain or IP — registrar, status, expiry dates, nameservers, and contacts. Whois Lookup Network Tools My IP Address Detect your public IPv4 and IPv6 addresses with geolocation, ISP name, and a live map. View My IP Ping Send ICMP echo requests to any hostname or IP and see real-time round-trip times and packet loss statistics. Ping a Host Traceroute Trace the network path hop-by-hop with real-time results and geolocation data for each router along the route. Run Traceroute Blacklist / RBL Check Check an IP address or domain against 15+ major DNS-based blocklists in parallel. Check Blacklists SSL Certificate Check Inspect SSL/TLS certificate details, expiry date, SANs, key info, and certificate chain for any hostname. Check Certificate HTTP Headers View HTTP response headers and redirect chains. Highlights security headers and flags missing ones. Check Headers HTTP/2 & HTTP/3 Checker Test whether a site supports HTTP/2 and HTTP/3. Checks ALPN negotiation, Alt-Svc advertisement, HTTPS redirect, and HSTS configuration. Check Protocol Support Port Checker Test whether a TCP port is open or closed on any hostname or IP address. Grabs server banners for SSH, SMTP, FTP, and more. Check a Port Email Tools Email Health Check Get a combined SPF + DMARC health grade (A–F) with a per-check breakdown and actionable recommendations for your domain. Check Email Health SPF Checker Look up and validate SPF records for any domain. Recursively expands all include chains and flags errors. Check SPF Record DMARC Checker Look up and validate DMARC records for any domain. Every tag is explained with validation status and warnings. Check DMARC Record DKIM Checker Look up and validate DKIM public keys for any domain and selector. Checks key size, flags, and configuration. Check DKIM Record Email Header Analyzer Paste raw email headers to trace the delivery path, check SPF/DKIM/DMARC results, and find routing delays. Analyze Headers SPF Generator Build a valid SPF record for your domain. Select email providers, enter IP ranges, and generate a ready-to-publish TXT record. Build SPF Record DMARC Generator Build a valid DMARC record for your domain. Set policy, reporting URIs, and alignment options. Build DMARC Record MTA-STS Checker Validate MTA-STS DNS records and policy files. Check mode, max_age, MX coverage, and policy file reachability. Check MTA-STS BIMI Checker Validate BIMI DNS records, fetch and preview the SVG brand logo, and check VMC certificate URLs. Check BIMI