IPv4 vs IPv6, explained
You may see two very different-looking addresses for your connection. Here’s why.
IPv4: the original
IPv4 addresses look like 203.0.113.42 — four numbers, each 0–255. There are about 4.3 billion of them, which sounded limitless in the 1980s and ran out years ago. ISPs now share IPv4 addresses among many customers using carrier-grade NAT, which is why your IPv4 might be shared.
IPv6: the successor
IPv6 addresses look like 2001:0db8:85a3::8a2e:0370:7334 — eight groups of hex. There are 340 undecillion of them, enough to give every grain of sand its own address. IPv6 lets each device have a unique public address again, without NAT.
Why do you see both IPv4 and IPv6?
Most networks now run “dual stack” — IPv4 and IPv6 side by side — during the long transition. Which one a site uses depends on what both ends support. If our panel shows an IPv6 address, your connection preferred it for this request; your IPv4 may still exist in parallel.