Random IP Generator
Documentation ranges are guaranteed never to be routed.
The random IP generator produces addresses from four ranges: RFC 5737 documentation blocks, RFC 1918 private ranges, public-looking IPv4, and the RFC 3849 IPv6 documentation prefix. Documentation is the default because those addresses are guaranteed never to be routed, so nothing you write can accidentally reach a real host.
How it works
- Documentation (RFC 5737): 192.0.2.0/24, 198.51.100.0/24 and 203.0.113.0/24. Reserved specifically for examples, never routed.
- Private (RFC 1918): 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16. Routable inside a network but never on the public internet.
- Public-looking IPv4: avoids reserved first octets, so it looks real. It may well belong to someone.
- IPv6 documentation (RFC 3849): the 2001:db8::/32 prefix, the IPv6 equivalent of the RFC 5737 blocks.
Host octets avoid 0 and 255, which are the network and broadcast addresses in a /24 and are not assignable to a host.
Examples
Documentation addresses
Range
Documentation (RFC 5737)
How many
5
Result
203.0.113.42, 192.0.2.181, 198.51.100.7, 203.0.113.219, 192.0.2.66
All three reserved blocks appear. These are the addresses to use in a blog post, a diagram or a config example.
IPv6 documentation addresses
Range
IPv6 documentation
How many
2
Result
2001:db8:4f1a:c30e:0091:ab77:d412:5e08 and one more
The 2001:db8 prefix is fixed and the remaining six groups are random hex, which is the standard shape of an IPv6 example address.
Frequently asked questions
Which range should I use for documentation or a screenshot?
The RFC 5737 blocks. 192.0.2.x, 198.51.100.x and 203.0.113.x. They exist for exactly this purpose and are guaranteed never to be routed, so an address in a tutorial cannot point at somebody’s server. Using a public-looking address in published documentation regularly sends unwanted traffic to whoever owns it.
Is a public-looking address safe to use?
Not in anything you publish. Those addresses are generated to look routable, which means they may well belong to a real organisation. Use them only for local test fixtures that never leave your machine.
Why do the addresses never end in 0 or 255?
Because in a /24 those are the network and broadcast addresses and cannot be assigned to a host. Generating them would produce test data that fails validation in anything doing a proper subnet check.
Can these be used to hide my real IP address?
No. Generating a string that looks like an IP address does nothing to your network connection. Your real address is determined by your connection, not by text on a page.