The internet runs on IP addresses. For decades, IPv4 was the only standard — but it's running out of addresses. IPv6 was designed to solve this. Here's what you need to know.
IPv4: The Classic Internet Protocol
IPv4, introduced in 1981, uses 32-bit addresses expressed as four decimal numbers:
93.184.216.34
This gives roughly 4.3 billion possible addresses. That sounds like a lot — but with billions of smartphones, smart devices, and servers, we ran out around 2012.
IPv6: The Future
IPv6 uses 128-bit addresses written in hexadecimal:
2001:0db8:85a3::8a2e:0370:7334
The address space: 340 undecillion addresses (3.4 × 10^38). Enough for every grain of sand on Earth to have billions of IP addresses.
Key Differences
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address length | 32-bit | 128-bit |
| Address example | 192.168.1.1 | fe80::1 |
| Address space | 4.3 billion | 340 undecillion |
| NAT required | Yes | No |
| IPSec support | Optional | Mandatory (in spec) |
| Header complexity | Variable | Simplified, fixed |
| Current usage | ~70% | ~40% |
What Is NAT and Why Does IPv6 Eliminate It?
Network Address Translation (NAT) lets multiple devices share a single public IPv4 address. Your router does this: your laptop and phone both get private addresses (192.168.x.x) but share one public IP.
IPv6 has enough addresses for every device to have its own globally routable address — no NAT needed. This simplifies networking and improves performance.
Do You Have IPv6?
Check with our IP checker. If your IP starts with numbers like 2001: or fe80:, you have IPv6. Many ISPs now support both IPv4 and IPv6 simultaneously (dual stack).
Conclusion
IPv6 solves IPv4's exhaustion problem and adds technical improvements. Migration is slow but inevitable — both protocols will coexist for years to come.