Address for testing
IPv4 and IPv6 from reserved ranges - safe to publish, points at nobody.
Runs locally in your browser. Nothing you generate is ever sent to a server.
Press "Generate" for an address.
Range
Reserved ranges only - these never point at a real host on the internet.
Press Generate for an IP address drawn from ranges that are reserved rather than routable. It is built for tests, tutorials and sample configuration, where using somebody else's real address causes problems that surface much later.
Every routable IPv4 address is allocated to somebody. An address invented at random for a tutorial or a test fixture will, sooner or later, be a real host - and then a copied firewall rule blocks a real company, or a load test points at a stranger's server. The standards body set aside three ranges specifically so that documentation would never have to guess: 192.0.2.0/24, 198.51.100.0/24 and 203.0.113.0/24. Using them removes the problem completely.
The private ranges - 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16 - are what real internal networks use, so they are the right choice when your test data should look like a corporate LAN. They are never routed on the public internet, so they are equally safe to publish.
The IPv6 mode uses 2001:db8::/32, the documentation prefix, and writes addresses in the standard shortened form with a double colon where a run of zero groups is collapsed. This is the form that trips up naive parsers, which makes it useful for testing.
The host portion of the address is drawn from your browser's cryptographic random source with rejection sampling, while the network portion stays fixed to keep the address inside its reserved range. Repeats within a batch are removed.
Addresses from ranges reserved for documentation and private networks, so nothing you generate belongs to a real host on the public internet.
Because every routable address belongs to somebody. Putting one in a test, a firewall rule or a tutorial can send traffic or blame to a real organisation, which is a mistake that is easy to make and hard to notice.
The documentation ranges 192.0.2.0/24, 198.51.100.0/24 and 203.0.113.0/24, the private ranges 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16, and 2001:db8::/32 for IPv6.
Yes. Switch to IPv6 and addresses are drawn from the 2001:db8::/32 documentation prefix, in the standard shortened form.
Yes. Set the count up to 200 and press once, then Copy All to paste the list straight into a fixture or a config file.
Yes. They are syntactically valid and correctly formatted, which is what matters when you are testing parsers, forms and log pipelines.