If you've ever looked at an IP address, it probably looked something like 203.0.113.42 — that's an IPv4 address. But the internet is gradually moving to a newer generation called IPv6. Here's what's different, and why the change is happening at all.
What is IPv4?
IPv4 is made of four number blocks between 0 and 255, separated by dots (like 192.168.1.10). That structure provides about 4.3 billion unique addresses — a number that seemed enormous in the 1980s, but has effectively run out given the explosive growth of mobile devices, smart gadgets, and IoT.
What is IPv6?
IPv6 was designed to solve exactly that shortage. It uses eight groups of four hexadecimal digits, like:
2001:0db8:85a3:0000:0000:8a2e:0370:7334
That structure provides roughly 340 undecillion addresses — enough to assign several unique IPv6 addresses to every grain of sand on Earth.
Key differences
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address length | 32 bits | 128 bits |
| Format | Dotted decimal (192.168.1.1) | Colon-separated hex (2001:db8::1) |
| Address count | ~4.3 billion | Effectively unlimited |
| NAT (address sharing) | Usually required | Usually unnecessary |
| Support today | Universal | Growing, not yet universal |
Why hasn't everyone switched to IPv6 yet?
A full migration to IPv6 requires updating routers, ISPs, servers, and legacy software — a process that's been underway for years and still isn't finished. To bridge the gap, most networks rely on NAT (Network Address Translation) so multiple devices can share one public IPv4 address, which we explain in Private vs Public IP.
Which one am I using?
Today, many connections use both at once (called dual-stack). To see exactly which address your current device or connection is getting, open the Show-IP.ir homepage — your current IP address shows up immediately along with full network details.
Key takeaways
- IPv4 is older, more common, and limited to about 4.3 billion addresses.
- IPv6 is newer and effectively never runs out of addresses.
- Most networks today run both simultaneously (dual-stack).
- NAT is what lets IPv4 networks keep working despite the address shortage.