Turn complex subnet notations into actionable data. Instantly expand any CIDR block or hyphenated range into a complete, copyable list of every valid IP address.
Firewalls often require explicit, line-by-line IP declarations. Convert abstract CIDR logic into massive text files instantly.
Generate massive, line-separated text files containing exactly the IPs you want to test, ensuring your automated Nmap security scans never hit unintended servers.
The engine accepts both rigid IT standards (like `10.0.0.0/24`) and messy human inputs (like `192.168.1.5 - 192.168.1.15`), calculating the exact boundaries flawlessly.
Generating 65,000 text strings usually requires a backend server. We utilize an optimized JavaScript Array construction loop that completes the task directly in your CPU in milliseconds.
Classless Inter-Domain Routing (CIDR) is the shorthand method network engineers use to describe massive blocks of IP addresses. Instead of writing out a document containing 256 distinct IP addresses to send to a firewall, they simply write 192.168.1.0/24.
While CIDR is a brilliant concept for human communication and advanced routers, many legacy software systems are "dumb". They do not understand the complex bitwise math required to parse a /24 notation.
It is a common misconception that an IP address like 192.168.1.255 just "rolls over" to 192.168.2.0 like a car odometer.
In reality, the computer is converting the IP address into a massive 32-bit integer (e.g., 3,232,236,031), adding +1 to the integer, and then converting it back to the dot-decimal string format.
When you submit a /24 block to our tool, the engine mathematically determines that there are 32 minus 24 = 8 bits available for hosts. 28 equals 256. The engine then simply runs a JavaScript loop 256 times, adding +1 to the base integer on each loop, and pushing the resulting string to the text box.
An inexperienced developer might see a 10.0.0.0/8 network block and try to expand it using an online script.
A /8 subnet contains exactly 16,777,216 IP addresses. If a JavaScript array attempts to hold 16 million text strings in memory simultaneously, the browser tab will instantly crash, consuming gigabytes of RAM. Our tool institutes a strict safety limit (maximum 65,536 IPs, which is a /16) to prevent you from accidentally crashing your computer.