> convert | subnet | analyze <
// Convert IP addresses between formats and calculate subnets
CIDR SUBNET INFO:
5 IP Formats
Convert between dotted decimal, integer, hexadecimal, binary, and octal representations instantly.
CIDR Calculator
Enter IP/prefix notation to calculate network address, broadcast, host range, and subnet mask.
Class Detection
Automatically detect IPv4 address class (A, B, C, D, E) based on the first octet.
// ABOUT IP ADDRESS CONVERSION
How IPv4 Addressing Works:
An IPv4 address is a 32-bit unsigned integer, commonly written in dotted decimal notation as four octets separated by dots. Each octet represents 8 bits (0-255). CIDR notation appends a prefix length to define subnet boundaries.
Example:
192.168.1.1 = 3232235777 = 0xC0A80101
Common Use Cases:
- >Network configuration and troubleshooting
- >Subnet planning and IP allocation
- >Firewall rules and ACL configuration
- >Understanding CIDR notation and subnet masks
- >Converting between IP address representations
>> frequently asked questions
Q: What is an IP address?
A: An IP (Internet Protocol) address is a unique numerical identifier assigned to every device connected to a network. IPv4 addresses are 32-bit numbers, typically written as four decimal octets (e.g., 192.168.1.1).
Q: What is the difference between IPv4 and IPv6?
A: IPv4 uses 32-bit addresses (about 4.3 billion unique addresses), while IPv6 uses 128-bit addresses (virtually unlimited). IPv4 is written in dotted decimal notation (192.168.1.1), while IPv6 uses hexadecimal groups separated by colons (2001:db8::1).
Q: What is CIDR notation?
A: CIDR (Classless Inter-Domain Routing) notation represents an IP address followed by a slash and the prefix length (e.g., 192.168.1.0/24). The prefix length indicates how many bits are used for the network portion, determining the subnet size.
Q: What is a subnet mask?
A: A subnet mask is a 32-bit number that divides an IP address into network and host portions. For example, 255.255.255.0 (/24) means the first 24 bits identify the network and the last 8 bits identify hosts within that network.
Q: What are private IP address ranges?
A: Private IP ranges reserved for internal networks are: 10.0.0.0/8 (Class A), 172.16.0.0/12 (Class B), and 192.168.0.0/16 (Class C). These addresses are not routable on the public internet and are used within local networks.
// OTHER LANGUAGES
References
How we make sure
We check this tool with the automated test suites linked below. Example checks are shown in their original language.
- Verification method
- Check IPv4/uint32 conversion at boundaries and fixed samples.
- Comparison reference
- Independent four-byte integer arithmetic assertions.
- Verification scope
- These samples and boundaries do not prove correctness for every input.
Test source and cases (select a file to read it)
-
legacy-reliability.test.js
- IPv4 converter: address boundaries match independent uint32 byte arithmetic
These checks cover the listed examples and boundaries, not every possible input. Round trips and checks using the same library are not independent verification.