Free Networking Tools
Network-layer tools for diagnosing connectivity, mail-server config, hosting, and CDN setup — DNS queries, IP lookups, HTTP header inspection, and WHOIS records. Everything runs on Cloudflare Workers and DNS-over-HTTPS at the edge, so lookups are fast from anywhere. No signup, no logging.
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Reverse DNS Lookup
Resolve an IPv4 or IPv6 address back to its hostname via PTR records.
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DNS Query
Query A, AAAA, MX, TXT, CNAME, NS, and other DNS records for a domain.
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What is my IP?
Show your current public IP address, with a few useful headers from your request.
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HTTP Header Viewer
Inspect the HTTP response headers, status codes, and redirect chains for any URL.
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WHOIS Lookup
Look up the registration record for any domain via RDAP — registrar, expiry, nameservers, status.
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IP WHOIS
Look up the registered owner of any IPv4 or IPv6 address via the Regional Internet Registry RDAP.
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Domain Info
One-glance domain summary — registrar, age, expiry, nameservers, A/AAAA, MX records.
Retired tools
These three tools needed raw network access that modern serverless platforms don't provide. The slugs still resolve to short explainer pages with the right CLI alternatives.
- Ping — ICMP isn’t available from serverless runtimes. Use the OS’ built-in ping or a multi-region probe.
- Traceroute — Needs raw IP/UDP packets which Workers don’t expose. CLI traceroute / mtr or a looking-glass service work better.
- Port Check — A single-edge probe is rarely more useful than nc on your own machine or check-host.net’s multi-region check.