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Network Tool

IP Address Lookup & Analyzer

Validate and analyze any IPv4 or IPv6 address instantly. See binary, decimal, and hex representations, classify addresses as public or private (RFC 1918), and calculate subnet details using CIDR notation. This free IP address lookup tool computes network addresses, broadcast addresses, subnet masks, wildcard masks, and usable host ranges entirely in your browser — no external API calls, no data sent to any server. Supports IPv4 vs IPv6 address checking, IP subnet calculation, and private IP range identification. Works offline.

ip-lookup.tool

IP Address Analysis

Subnet Calculation

Common Private IP Ranges Reference
Range CIDR Type Addresses
10.0.0.0 – 10.255.255.25510.0.0.0/8Private (RFC 1918)16,777,216
172.16.0.0 – 172.31.255.255172.16.0.0/12Private (RFC 1918)1,048,576
192.168.0.0 – 192.168.255.255192.168.0.0/16Private (RFC 1918)65,536
127.0.0.0 – 127.255.255.255127.0.0.0/8Loopback16,777,216
169.254.0.0 – 169.254.255.255169.254.0.0/16Link-Local65,536
224.0.0.0 – 239.255.255.255224.0.0.0/4Multicast268,435,456
240.0.0.0 – 255.255.255.255240.0.0.0/4Reserved268,435,456
::1/128::1/128IPv6 Loopback1
fe80::/10fe80::/10IPv6 Link-Local~1.2×1024
fc00::/7fc00::/7IPv6 Unique Local~5.9×1037

Frequently Asked Questions

How do I find information about an IP address?
Enter any IPv4 or IPv6 address into the input field above to instantly see its version, binary/decimal/hex representations, classification (private, public, loopback, link-local, multicast), and IP class. Add a CIDR prefix length (e.g., /24) to calculate subnet details including network address, broadcast address, usable host range, subnet mask, and wildcard mask. All processing happens locally in your browser — no data is sent to any server, and no external API calls are made.
What is the difference between IPv4 and IPv6?
IPv4 uses 32-bit addresses written as four decimal octets (e.g., 192.168.1.1), providing about 4.3 billion unique addresses. IPv6 uses 128-bit addresses written as eight groups of four hexadecimal digits separated by colons (e.g., 2001:0db8::1), providing approximately 3.4 × 1038 addresses. IPv6 was created to solve IPv4 address exhaustion and includes improvements like built-in IPsec support, simplified packet headers, and elimination of NAT.
What are private IP address ranges (RFC 1918)?
RFC 1918 defines three private IPv4 address ranges not routable on the public internet: 10.0.0.0/8 (~16.7 million addresses), 172.16.0.0/12 (~1 million addresses), and 192.168.0.0/16 (~65,000 addresses). These are used for local area networks behind NAT routers. Other reserved ranges include 127.0.0.0/8 for loopback and 169.254.0.0/16 for link-local auto-configuration. The reference table above lists all common reserved ranges.
How does CIDR notation and subnetting work?
CIDR (Classless Inter-Domain Routing) notation appends a prefix length to an IP address, like 192.168.1.0/24. The prefix length indicates how many leading bits define the network portion. A /24 means 24 network bits and 8 host bits — giving 256 total addresses (254 usable hosts, minus network and broadcast). Subnetting divides a larger network into smaller segments: a /24 can be split into two /25 subnets (128 addresses each) or four /26 subnets (64 addresses each). Use the subnet calculator above to explore these calculations interactively.
What is a subnet mask and how do I calculate it?
A subnet mask is a 32-bit number that separates the network and host portions of an IP address. It consists of consecutive 1-bits for the network part followed by 0-bits for the host part. For example, /24 = 255.255.255.0 (24 ones followed by 8 zeros in binary). The wildcard mask is the bitwise inverse: 0.0.0.255. To find the network address, perform a bitwise AND between the IP and subnet mask. The broadcast address has all host bits set to 1. Enter any IP with a CIDR prefix above to see all these values computed instantly.