Free Network Diagnostic Tools

DNS lookup, IP geolocation, WHOIS, port check, SSL cert inspector, HTTP headers, ASN lookup and more — no login, no limits, all free.

Your public IP address
Detecting…
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DNS lookup
Query A, AAAA, MX, TXT, NS, CNAME, PTR records
FREE
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IP geolocation
Country, city, ISP, ASN, timezone for any IP
FREE
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WHOIS lookup
Domain registrar, creation date, expiry, nameservers
FREE
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SSL certificate checker
Issuer, expiry, SANs, cipher, grade
FREE
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Port check — IP or FQDN
Check if TCP port(s) are open on any IP address or hostname
FREE
Quick:
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HTTP headers inspector
Server, security headers, redirects, status code
FREE
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ASN / BGP lookup
Autonomous system, prefixes, peering info for any IP or ASN
FREE
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Reverse DNS (PTR)
Resolve IP address back to hostname
FREE
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Email / MX record checker
MX, SPF, DKIM root, DMARC records for a domain
FREE
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Ping / latency test
HTTP-based round-trip time measurement to any URL
FREE

Runs from Cloudflare edge only — public internet view, independent of your location

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IP blacklist / reputation check
Check if IP is listed on spam / threat blocklists
FREE
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Subnet calculator
Network address, broadcast, host range, usable IPs
FREE
Legal & usage note: All tools query only publicly available information. DNS, WHOIS, IP geolocation, ASN, and SSL data are public by design. Port checking queries your own specified target — only test hosts you own or have explicit permission to test. No data you enter is stored by AuditXA.