About IP Address Lookup

Parse and validate IPv4/IPv6 addresses and CIDR ranges. Part of the DevTools Surf developer suite. Browse more tools in the Networking collection.

Use Cases

• Validating IP addresses in firewall rule configurations
• Calculating subnet ranges for network infrastructure planning
• Parsing CIDR blocks for cloud security group definitions
• Verifying IPv6 address format in DNS AAAA record entries

Tips

• Validate both IPv4 and IPv6 address formats instantly
• Parse CIDR notation to see the network range and host count
• Check whether an address is in a private or public range

Fun Facts

• IPv4's 32-bit address space provides 4,294,967,296 unique addresses, which were officially exhausted by IANA on February 3, 2011.
• IPv6 provides 340 undecillion (3.4 x 10^38) addresses, enough for roughly 670 quadrillion addresses per square millimeter of Earth's surface.
• The private IP ranges 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 were reserved by RFC 1918 in 1996.

FAQ

Does it lookup geolocation?

No — this is format-only validation. For geo-IP, use a dedicated service (MaxMind, ipinfo.io) that queries a geographic database.

What validations does it run?

Address format (IPv4/IPv6 syntax), range class (private, loopback, multicast, link-local), and whether it's within a specified CIDR.

IPv6 zone IDs?

Yes — link-local addresses like fe80::1%eth0 are parsed with the zone ID preserved. Rare outside local networking, but supported.

What about IPv4-mapped IPv6?

Detected (::ffff:a.b.c.d form). The tool notes when an IPv6 address is actually an IPv4 address in IPv6 clothing.