IP Address Validator & CIDR Subnet Calculator (IPv4 / IPv6)
Validate IPv4 and IPv6 addresses, check public vs. private ranges, calculate CIDR subnet masks, and convert IP formats in real time.
Input Workspace
Characters: 64Words: 3Lines: 3Size: 64 Bytes
Output Result
Time: 0 msOutput: 0 Bytes
Tool Customization
No customization controls needed for this tool. It transforms text automatically!
100% Client-Side Privacy & Large-Text Ready
Supports text inputs up to 50 MB. Computations execute entirely within your local browser memory with zero server uploads.
Validation Guide
About the IP Address Validator & CIDR Subnet Calculator (IPv4 / IPv6)
Configuring firewall allowlists, analyzing server security logs, setting up cloud VPC subnets, or validating user input forms requires verifying that IP addresses and CIDR notation blocks are syntactically valid and properly classified. The IP Address Validator & CIDR Subnet Calculator inspects IPv4 and IPv6 addresses in real time. It validates dot-decimal and hexadecimal notation, classifies public vs. private RFC 1918 / RFC 4193 ranges, computes CIDR network ranges (usable host IPs, broadcast addresses, subnet masks), and converts IPs to binary and integer formats.
In-Depth Technical Guide
How IP Address Validator & CIDR Subnet Calculator (IPv4 / IPv6)Works & What the Results Mean
Mechanics of IPv4 & IPv6 Address Architecture
IP addressing follows standardized IETF network protocols:
IPv4 Architecture (32 Bits): Formatted as 4 dot-decimal octets (0.0.0.0 to 255.255.255.255, e.g. 192.168.1.1).
Private Ranges (RFC 1918):10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16.
Loopback:127.0.0.0/8.
Link-Local (APIPA):169.254.0.0/16.
IPv6 Architecture (128 Bits): Formatted as 8 groups of 4 hexadecimal digits separated by colons (e.g. 2001:0db8:85a3:0000:0000:8a2e:0370:7334). Consecutive zero blocks can be compressed once with ::.
CIDR Subnet Math (Classless Inter-Domain Routing): A prefix length (e.g. /24) defines the network mask. A /24 IPv4 subnet provides $2^{32-24} = 256$ total addresses (254 usable hosts after reserving network and broadcast addresses).
Primary Everyday Applications
Cloud Networking & VPC Design: Calculating usable host ranges for AWS VPC and Kubernetes cluster subnets.
Firewall Rule Verification: Validating IP whitelists and CIDR blocks before deploying security policies.
Log Analysis: Checking whether client IP addresses in server access logs are public internet clients or internal private proxies.
Step-by-Step Guide
How to Use IP Address Validator & CIDR Subnet Calculator (IPv4 / IPv6)
1Type or paste an IPv4 address, IPv6 address, or CIDR block (e.g. 192.168.1.1 or 10.0.0.0/24) into the input field.
2The tool validates syntax and classifies the address in real time.
3Review the Validation Status badge (Valid IPv4 / Valid IPv6 vs. Invalid IP).
4Inspect the Classification Card detailing Address Type (Public Internet vs. Private RFC 1918, Loopback, Link-Local).
5If a CIDR prefix is provided, review the Subnet Calculations table showing Netmask, Network Address, Broadcast Address, and Usable Host Range.
6Click 'Copy IP Details' to copy the report to your clipboard.
Capabilities
Key Features & Highlights
Validates standard IPv4 dot-decimal and IPv6 128-bit hexadecimal addresses.
