Random IP Generator
Generate cryptographically random IPv4 or IPv6 addresses for testing, development, or network simulations. All addresses are generated server-side using a secure random source.
Common Use Cases
- Populating test databases with realistic-looking IP data
- Testing firewall rules and access control lists
- Network simulation and load testing
- Development and QA environments that need varied IP inputs
IPv4 vs IPv6 Address Spaces
IPv4 uses 32-bit addresses, providing approximately 4.3 billion unique addresses - A number that was exhausted by the early 2010s. IPv6 uses 128-bit addresses, providing 340 undecillion addresses (3.4 x 10^38), enough to assign billions of IPs to every atom on Earth. Despite this, IPv4 remains dominant due to legacy infrastructure and NAT.
| Property | IPv4 | IPv6 |
|---|---|---|
| Address length | 32 bits | 128 bits |
| Total addresses | ~4.3 billion | 340 undecillion |
| Notation | Dotted decimal (e.g. 192.168.1.1) | Colon-hex (e.g. 2001:db8::1) |
| NAT required? | Yes (for most deployments) | No (every device gets a public IP) |
| IANA exhaustion | 2011 (regional pools still active) | Not in foreseeable future |
| Adoption (2025) | Dominant (~60% of traffic) | Growing (~40% of traffic) |
Private and Reserved IP Ranges
Certain IP ranges are reserved for private networks, loopback, link-local, and multicast use. These addresses are not routable on the public internet. When generating random IPs for public network simulation, exclude these ranges.
IPv4 Reserved Ranges
| Range | Purpose | RFC | Routable? |
|---|---|---|---|
10.0.0.0/8 | Private network (Class A) | RFC 1918 | No |
172.16.0.0/12 | Private network (Class B) | RFC 1918 | No |
192.168.0.0/16 | Private network (Class C) | RFC 1918 | No |
127.0.0.0/8 | Loopback | RFC 990 | No |
169.254.0.0/16 | Link-local (APIPA) | RFC 3927 | No |
224.0.0.0/4 | Multicast | RFC 5771 | Limited |
100.64.0.0/10 | Shared address space (CGN) | RFC 6598 | No |
IPv6 Reserved Ranges
| Range | Purpose | RFC |
|---|---|---|
::1/128 | Loopback | RFC 4291 |
fc00::/7 | Unique local (private) | RFC 4193 |
fe80::/10 | Link-local | RFC 4291 |
ff00::/8 | Multicast | RFC 4291 |
2001:db8::/32 | Documentation only | RFC 3849 |
2002::/16 | 6to4 tunneling | RFC 3056 |
IPv4 vs IPv6 Global Adoption
Approximate share of internet traffic by IP version (Google data, 2025)
Frequently Asked Questions
Yes, for unit testing and validation logic. However, for integration tests that require realistic responses (geolocation, ISP data, etc.), use well-known public IP addresses instead - Randomly generated IPs may resolve to unallocated or private ranges that behave unexpectedly in external APIs.
Public IPs are globally unique and routable on the internet. Private IPs (RFC 1918 ranges: 10.x.x.x, 172.16-31.x.x, 192.168.x.x) are for internal networks only and are not directly accessible from the internet without NAT. This tool lets you choose between generating public or private addresses.
IPv6 adoption has been gradual due to the investment required to upgrade routers, firewalls, and legacy applications. NAT (Network Address Translation) also extended the useful life of IPv4 by allowing many devices to share a single public IP. Major mobile carriers (T-Mobile, Reliance Jio) and ISPs now issue IPv6 by default, which is driving the rapid adoption seen in recent years.