Random IPv4 Address Generator
About the IPv4 Address Generator
This tool operates in two modes. In random mode (leave the Base IP field empty) it generates the requested number of IPv4 addresses using a cryptographically secure random number generator. The addresses are not associated with any real device or network and are safe to use in test environments, mock data or documentation.
In range mode (enter a Base IP address) the tool calculates the network address for the given IP and CIDR prefix and lists the first N addresses sequentially from that network. For example, entering 192.168.1.50 with a /24 prefix will list addresses starting from 192.168.1.0. This is useful for planning IP allocations or testing firewall rules against a specific subnet.
The Public IPs only checkbox filters out all RFC 1918 private ranges (10.x.x.x, 172.16-31.x.x, 192.168.x.x), loopback addresses, link-local ranges and other reserved blocks, ensuring every result is a routable public address.
Common Use Cases
Application testing: Populate test databases with realistic-looking IP addresses without using real customer data. Random IPs avoid accidentally testing against live infrastructure and satisfy anonymisation requirements in test environments.
Network simulation: Generate a list of IPs in a specific subnet to test routing configurations, firewall rule sets or load balancer distributions in a lab environment where real addresses are not available.
Security research: Use synthetic IP sets when writing network scanners, parsers or log analysis scripts to ensure your tooling handles the full range of valid IPv4 addresses correctly without sending real traffic.
Documentation and presentations: Replace real IP addresses in screenshots, network diagrams and documentation with randomly generated ones to avoid inadvertently exposing internal network topology.
IPv4 Address Space Overview
IPv4 uses 32-bit addresses, giving a theoretical total of 4,294,967,296 (2^32) addresses. Of these, roughly 600 million are reserved for private networks, loopback, multicast, documentation and other special purposes, leaving approximately 3.7 billion routable public addresses. IANA allocated the last unassigned /8 blocks to the Regional Internet Registries in February 2011, marking the official exhaustion of the central IPv4 pool.
The transition to IPv6 is ongoing but IPv4 remains dominant for most internet traffic. Network address translation (NAT) extends the life of IPv4 by allowing many devices to share a single public address, but this introduces complexity and breaks end-to-end connectivity. Understanding IPv4 subnetting remains an essential skill for network administrators and developers.
Frequently Asked Questions
Are the generated IPs real?
In random mode the addresses are mathematically valid IPv4 addresses but are not guaranteed to be assigned to any device. Some may correspond to real hosts on the public internet. Never use them to test against live systems without permission. For testing that requires guaranteed non-routable addresses, use the RFC 1918 ranges or the documentation prefix 192.0.2.0/24.
How many addresses can I generate at once?
Up to 500 per request. For larger sets, run multiple requests and combine the results. There is no rate limiting for reasonable use.
Why does range mode start from the network address rather than the IP I entered?
The tool automatically applies the subnet mask to find the network address for the given prefix length. This is the standard behaviour for IP subnet calculations. If you enter 192.168.1.50 with /24, the network address is 192.168.1.0 and listing starts from there.
Can I generate IPv6 addresses?
Yes, visit our Random IPv6 Address Generator for 128-bit address generation with the same features.