IPv4 vs IPv6: What's the Difference?
Compare IPv4 and IPv6 address formats, capacity, speed, and compatibility. Learn which protocol your network uses and why the transition matters.
What Is IPv4?
IPv4 (Internet Protocol version 4) has been the dominant internet protocol since the 1980s. It uses 32-bit addresses, providing approximately 4.3 billion unique addresses. An IPv4 address looks like 8.8.8.8 or 192.168.0.1.
Despite address exhaustion, IPv4 remains widely used because of its simplicity and universal support across all network equipment and software.
What Is IPv6?
IPv6 (Internet Protocol version 6) was introduced to solve IPv4 address exhaustion. With 128-bit addresses, IPv6 provides 340 undecillion unique addresses — more than enough for every device on Earth for centuries.
An IPv6 address looks like 2001:4860:4860::8888. IPv6 also includes built-in improvements for routing efficiency, auto-configuration, and security.
Key Differences
Address format: IPv4 uses dotted decimal (4 octets); IPv6 uses hexadecimal groups separated by colons.
Address space: IPv4 has ~4.3 billion addresses; IPv6 has virtually unlimited addresses.
Configuration: IPv4 often requires DHCP; IPv6 supports stateless auto-configuration.
NAT dependency: IPv4 relies heavily on NAT for home networks; IPv6 allows direct end-to-end connectivity.
Header size: IPv6 has a simplified header, which can improve routing performance on modern hardware.
Do I Have IPv6?
Many ISPs now provide dual-stack connectivity, meaning you have both IPv4 and IPv6 addresses. Our homepage displays your IPv4 address automatically. If your ISP supports IPv6, you may see a separate IPv6 address depending on your network configuration.
You can test any IP address — IPv4 or IPv6 — using our IP Lookup tool to see geolocation and network details.
Frequently Asked Questions
Is IPv6 faster than IPv4?
IPv6 is not inherently faster, but it can reduce latency in some cases by eliminating NAT overhead and enabling more direct routing paths. Real-world speed depends on your ISP's infrastructure and the destination server.
Why hasn't the world fully switched to IPv6?
Transitioning billions of devices, routers, and services takes decades. IPv4 and IPv6 coexist through dual-stack networking and tunneling technologies. Most modern networks support both protocols.
Can I lookup an IPv6 address?
Yes. Our IP Lookup tool accepts both IPv4 and IPv6 addresses and returns geolocation, ISP, and ASN information for either format.