Address formats · 3 minute read

IPv4 vs. IPv6: what your IP address means.

IPv4 and IPv6 are two versions of the Internet Protocol. Both give networks a way to address and route traffic. The difference you will notice first is how their addresses look.

How to recognise each version

IPv4 and IPv6 address formats
Version	Example*
IPv4	`203.0.113.42`
IPv6	`2001:db8::42`

IPv4 uses four numbers separated by dots. IPv6 uses groups of hexadecimal digits separated by colons.

*These are reserved documentation examples, not your address. In IPv6, :: abbreviates one consecutive set of zero groups. A shorter-looking address can still be a complete IPv6 address.

Why IPv6 exists

IPv4 uses 32-bit addresses, giving it roughly 4.3 billion possible combinations. IPv6 uses 128 bits and has a vastly larger address space. It allows networks to assign globally routable addresses to many more devices without relying on the same degree of address sharing.

IPv4 is still widely used. Many networks support both versions at the same time, a setup called dual stack. Your device and the destination determine which version a particular connection uses.

Why two IP websites can show different results

One website might receive your request over IPv4 and another over IPv6. Both results can describe your connection accurately. VPN routing and proxies can also change the address a particular site sees.

Our tool reports the version used for the request that reached this website. It does not independently probe an IPv4-only and IPv6-only destination, so one result cannot tell you whether both versions are available.

What to check when troubleshooting

Note the version as well as the address. An IPv4-only allowlist cannot accept an IPv6 address. Ask the service which format it supports.
Compare like with like. A change from an IPv4 result to an IPv6 result does not, on its own, prove that a VPN is working or failing.
Refresh after changing networks. A result from before you connected a VPN or switched Wi-Fi is a snapshot of the earlier request.
Use a dedicated test for a specific problem. Investigating IPv6 reachability or a DNS leak needs more than a single public-IP check.

Is IPv6 faster or safer?

The address format alone does not guarantee speed, privacy, or security. Performance depends on routing and network conditions. A globally routable address does not mean a device accepts incoming connections; firewall rules still matter. You do not usually need to disable a working IP version just because its address looks unfamiliar.