The full IPFerret toolkit.
Every utility we ship — lookup, diagnostic, utility, reference. Free, CORS-friendly API on every endpoint, zero tracking, dark mode that actually works.
Lookup
Investigate a specific IP, domain, ASN, or country.
My public IP
Your IP, ISP/ASN, approximate location, cloud provider detection, browser fingerprint — at a glance.
OpenIP lookup
Look up geo, ASN, hostname, and privacy signals for any IPv4 or IPv6 address. Shareable URLs.
/ip-lookup/1.1.1.1OpenWHOIS / RDAP
Allocation, registrant, abuse contact, CIDR ranges, and origin AS for any IP. Live RDAP across the five RIRs.
/whois/2606:4700::1OpenDNS lookup
Resolve A, AAAA, MX, TXT, NS, CNAME, SOA, CAA, PTR, or SRV for any domain. Powered by Cloudflare DNS-over-HTTPS.
/dns?name=example.com&type=MXOpenASN explorer
Holder, country, type, announced prefixes, and cloud detection for any Autonomous System.
/asn/AS13335OpenCountry index
IP allocation overview by country — RIR, sample routed ASNs, regional metadata.
/country/JPOpenEmail deliverability
Check MX, SPF, DMARC, and (optionally) DKIM for any domain. Catches misconfigs that send legitimate mail to spam.
/email?domain=google.comOpenSSL / TLS checker
Inspect any site's cert chain, expiration, protocol, cipher, ALPN, and HSTS. With an A–F grade.
/tls?host=cloudflare.comOpen
Diagnostic
Inspect your connection — what your browser reveals, what your network is doing.
Request headers
Every header your browser sent us, plus parsed TLS / HTTP version. Useful when debugging proxies, CDNs, or VPN setups.
OpenUser-agent parser
Decode your browser user-agent string into browser, OS, and device — and copy it.
OpenIPv6 reachability test
Did your connection reach IPFerret over IPv6 or IPv4? Quick yes/no with the actual address.
OpenDNS leak test
Learn how DNS leaks happen, why they matter for privacy, and how to confirm your VPN is routing DNS safely.
OpenWebRTC leak test
In-browser ICE probe that shows which IP addresses your browser would expose to a peer connection.
Open
Utility
Bit-math and notation helpers for network engineers.
Bulk reverse DNS
Paste up to 100 IPv4 or IPv6 addresses and get the PTR hostname for each. CSV export, parallel lookups.
/reverse-dns?ips=8.8.8.8,1.1.1.1OpenCIDR / subnet calculator
Network, broadcast, host count, netmask, wildcard for any IPv4 or IPv6 CIDR. Fully client-side.
/cidr-calculatorOpenIPv6 toolkit
Expand and compress IPv6 notation, convert to ip6.arpa reverse-DNS form, identify special ranges.
OpenMAC vendor (OUI) lookup
Resolve any MAC address to its IEEE-registered manufacturer using the OUI database.
Open
Reference
Concept explainers — the underlying mechanics in plain language.
CGNAT explainer
Carrier-grade NAT in plain English — what it is, the 100.64.0.0/10 shared range, how to tell, and workarounds.
OpenWhat is my IP? (explainer)
Plain-language guide to public vs. private IPs, IPv4 vs. IPv6, and what websites can learn from your IP.
OpenNetworking glossary
20+ plain-English definitions — ASN, BGP, CIDR, DNS, NAT, MTU, RDAP, IPv6, QUIC, and more. Cross-linked back into the tools.
Open
Shell-friendly
Every tool is also a curl one-liner.
The big tools have plain-text shortcuts so they pipe cleanly into jq or your shell prompt. Everything else is JSON under /api/.
$ curl ipferret.com/ip $ curl ipferret.com/ua $ curl ipferret.com/json $ curl 'ipferret.com/api/dns?name=example.com&type=A' $ curl ipferret.com/api/whois/1.1.1.1 $ curl ipferret.com/api/lookup/8.8.8.8