IP Lookup🔒 100% local
Analyse an IPv4/IPv6 address locally: class, private or public range, binary, hex and reverse DNS name. Privacy-first, no server uploads, no tracking.
Related Tools
Takes an IPv4 or IPv6 address, with or without a CIDR suffix, and derives everything it can from the bits themselves: the class, whether the range is private, loopback, link-local, documentation or globally routable, the binary and hex forms, the reverse-DNS name, and for IPv4 the network, netmask and usable host range. Nothing is looked up - there is no call to a geolocation or whois service, so neither the address you are curious about nor your own address leaves the machine.
How to use it
- Paste an address or a block, for example 8.8.8.8 or 192.168.1.10/24.
- Press Process.
- Read the field list and the Findings bullets, then run the printed dig -x and whois lines in your own shell if you need the real registry records.
Worked example
8.8.8.8becomesAddress: 8.8.8.8
Version: IPv4 (32-bit)
Class: A
Type: Public (globally routable)
Octets: a=8 b=8 c=8 d=8
Binary: 00001000.00001000.00001000.00001000
Hex: 0x08080808 Decimal: 134744072
Reverse DNS: 8.8.8.8.in-addr.arpa
Reverse DNS (PTR):
dig -x 8.8.8.8 +short
host 8.8.8.8
Who owns it:
whois 8.8.8.8 # allocation + abuse contact (ARIN/RIPE/APNIC…)
Public: 8.8.8.8 is in a single-host /32
Findings:
• This address IS routable — it is visible to every network between the client and the server. Treat it as public information.
Privacy note: any "IP lookup" service sees the address you type AND your own IP. This tool is entirely offline — it does the bit-level work locally and never contacts a geolocation API.
Why this tool does not show a city: IP-to-location data is a commercial guess with error bars measured in tens of kilometres; it cannot identify a person and is trivially defeated by a VPN.The Type comes from the RFC ranges coded into the page, and the last two lines state plainly why no city or ISP appears.
192.168.1.10/24becomesAddress: 192.168.1.10/24
Version: IPv4 (32-bit)
Class: C
Type: Private (RFC 1918)
Octets: a=192 b=168 c=1 d=10
Binary: 11000000.10101000.00000001.00001010
Hex: 0xC0A8010A Decimal: 3232235786
Reverse DNS: 10.1.168.192.in-addr.arpa
Network: 192.168.1.0/24
Netmask: 255.255.255.0
Host range: 192.168.1.1 - 192.168.1.254
Reverse DNS (PTR):
dig -x 192.168.1.10 +short
host 192.168.1.10
Who owns it:
whois 192.168.1.10 # allocation + abuse contact (ARIN/RIPE/APNIC…)
Public: 192.168.1.10 is in /24
Findings:
• This address is NOT globally routable (Private (RFC 1918)). Not routable on the public internet — inside your network only.
Privacy note: any "IP lookup" service sees the address you type AND your own IP. This tool is entirely offline — it does the bit-level work locally and never contacts a geolocation API.
Why this tool does not show a city: IP-to-location data is a commercial guess with error bars measured in tens of kilometres; it cannot identify a person and is trivially defeated by a VPN.With a prefix the tool also prints the network, mask and host range: net = 192.168.1.0, mask = 255.255.255.0, usable hosts 1 to 254.
When to use it
- Checking whether an address that appeared in a log line is routable or internal before you chase it.
- Working out the network, netmask and host range of a /26 without opening a subnet calculator.
- Getting the in-addr.arpa name for an IPv4 address when you are about to write a PTR record.
What it does not do
- It contacts nothing, so it cannot tell you the city, ISP or owner of an address; it prints the dig and whois commands for you to run yourself.
- The range classification comes from hard-coded RFC ranges rather than live registry data, so space reassigned since those documents will still be labelled by its original purpose.
- IPv6 is handled at address level only: the compressed form is produced by trimming zero groups rather than by the RFC 5952 rules, so it can differ from the canonical spelling on addresses with several zero runs.
- One address per run - pasting a comma-separated list is treated as an invalid address and errors out.
- The reverse-DNS field is a name to query, not a resolved answer; there is no DNS resolution anywhere in the tool.