IPv4 vs IPv6: What's the Difference?

The internet is slowly migrating from IPv4 to IPv6. Here's what changed, why it was necessary, and what it means for you.

The problem: IPv4 ran out

IPv4, designed in the early 1980s, uses 32-bit addresses like 198.51.100.7. That allows roughly 4.3 billion addresses — which seemed infinite in 1981 and ran out around 2011. Workarounds like NAT (sharing one public IP among many devices) kept IPv4 alive, but the long-term fix is IPv6.

The solution: IPv6

IPv6 uses 128-bit addresses like 2001:db8:85a3::8a2e:370:7334. The address space is about 340 undecillion (3.4×10³⁸) — enough to give every grain of sand on Earth trillions of addresses. Beyond size, IPv6 also brings:

• No need for NAT — every device can have a globally unique address
• Simpler packet headers, more efficient routing
• Built-in support for IPsec and better autoconfiguration

Side by side

• Format: IPv4 — four numbers 0–255 separated by dots. IPv6 — eight groups of hex digits separated by colons (zeros can be compressed with ::).
• Address count: IPv4 ~4.3 billion; IPv6 ~3.4×10³⁸.
• Configuration: IPv4 often needs DHCP/NAT; IPv6 can self-configure.
• Adoption: over 40% of Google's traffic is IPv6 as of the mid-2020s, and growing steadily.

Is IPv6 faster?

Marginally, sometimes. IPv6 can avoid NAT overhead and take more direct routes, but in practice the difference is small. What matters more: some networks now offer IPv6-only service with translation layers for old IPv4 sites, so IPv6 support is increasingly essential rather than optional.

Which one am I using?

Check the homepage — we show both your IPv4 and IPv6 address (if you have one). Many connections today are dual-stack, meaning you use both simultaneously: IPv6 when a site supports it, IPv4 otherwise.