IPv4 vs IPv6: What's the Difference and Why It Matters

Every device connected to the internet needs an IP address. For decades, IPv4 has been the standard. But with billions of new devices coming online, the internet is slowly transitioning to IPv6. Here is what you need to know.

What Is IPv4?

IPv4 (Internet Protocol version 4) uses 32-bit addresses written as four numbers separated by dots, like 192.168.1.1. Because it is 32-bit, IPv4 supports about 4.3 billion unique addresses. That sounded like plenty in the 1980s, but today we have run out.

What Is IPv6?

IPv6 (Internet Protocol version 6) uses 128-bit addresses written as eight groups of hexadecimal numbers separated by colons, like 2001:0db8:85a3::8a2e:0370:7334. With 128 bits, IPv6 supports an effectively unlimited number of addresses—about 340 undecillion.

Key Differences at a Glance

Why the Transition Matters

The world ran out of new IPv4 addresses years ago. Without IPv6, we rely on workarounds like NAT (Network Address Translation), which complicates networking. IPv6 restores the original vision of the internet: every device gets its own unique, globally routable address.

Check Your IP Address

Curious whether you are already using IPv6? Use our free IP address lookup tool to see your public IPv4 and IPv6 addresses, user agent, and browser information.