IPv4 vs IPv6: what is the difference?
IPv4 and IPv6 are both versions of Internet Protocol, but they differ in address size, deployment patterns, and operational behavior. Most networks still carry a lot of IPv4 traffic, while IPv6 continues to expand for growth and simplicity.
- Why IPv4 exhaustion pushed IPv6 adoption.
- Why dual-stack is common on modern networks.
- Why a site may show IPv4 only or IPv6 only depending on host and path.
Address size and format
IPv4 uses 32-bit addresses like 203.0.113.10.
IPv6 uses 128-bit addresses like 2001:db8::10.
Operational differences
IPv4 often depends on NAT because public address space is tight.
IPv6 was designed with a much larger address space so global addressing is easier.
What users notice
Some VPNs or home networks only carry IPv4.
Some mobile and fiber networks support both families and may prefer one for certain destinations.
How WhenIP helps
WhenIP checks both families using separate hosts so you can see what each path actually does.
That makes IPv6 problems easier to isolate than a single generic IP page.
Is IPv6 faster?
Sometimes, but it depends on routing, DNS, and your provider.
Can I use the internet without IPv6?
Yes, but some environments and future services work better when both families are available.
Last updated: March 29, 2026