What is the difference between IPv4 and IPv6?

IPv4 uses 32-bit addresses (about 4.3 billion total) written as four numbers like 192.168.1.1. IPv6 uses 128-bit addresses written as eight hexadecimal groups, providing a virtually unlimited supply of addresses for the growing internet.

Is IPv6 more secure than IPv4?

IPv6 was designed with IPsec encryption support built in, whereas IPsec is optional on IPv4. However, real-world security depends far more on your VPN, DNS, and browser configuration than on the IP version itself.

Can IPv6 cause a privacy leak with a VPN?

Yes. If your VPN does not route IPv6 traffic, your real IPv6 address can leak even while connected. Choose a VPN with IPv6 leak protection, or disable IPv6 if your VPN does not support it.

IPv4 vs IPv6: What's the Difference?

Q: Do I have IPv4, IPv6, or both?

Most modern networks run dual-stack, meaning your device has both an IPv4 and an IPv6 address. You can check both instantly on WhatsMyInfo.app — if both appear, you are using dual-stack.

What is an IP Address?

An IP (Internet Protocol) address is like a home address for your device on the internet. It allows other devices and servers to find and communicate with you.

There are two main versions: IPv4 (Internet Protocol version 4) and IPv6 (Internet Protocol version 6).

IPv4: The Original Standard

IPv4 was introduced in 1981 and is still the most widely used IP version today.

IPv4 Address Format:

192.168.1.1

Four numbers (0-255) separated by dots

IPv4 Key Facts:

Address length: 32 bits (4 bytes)
Total addresses: ~4.3 billion
Status: Running out of available addresses
Support: Universal — every device and network supports it

IPv6: The Future of the Internet

IPv6 was developed in the late 1990s to solve IPv4's address shortage. It provides a virtually unlimited number of IP addresses.

IPv6 Address Format:

2001:0db8:85a3:0000:0000:8a2e:0370:7334

Eight groups of four hexadecimal digits separated by colons

IPv6 Key Facts:

Address length: 128 bits (16 bytes)
Total addresses: 340 undecillion (340 trillion trillion trillion)
Status: Slowly replacing IPv4
Support: Growing — most modern devices support it

Key Differences Between IPv4 and IPv6

Feature	IPv4	IPv6
Address Length	32 bits	128 bits
Format	192.168.1.1	2001:db8::1
Total Addresses	~4.3 billion	340 undecillion
Security	Optional (IPsec)	Built-in (IPsec)
Speed	Standard	Slightly faster

Why Was IPv6 Created?

The internet was growing faster than expected, and we were running out of IPv4 addresses. With only 4.3 billion addresses available and billions of devices online (phones, computers, IoT devices), IPv6 was necessary.

More devices: Every smartphone, tablet, smart home device needs an IP
IoT explosion: Billions of connected devices joining the internet
Better security: IPv6 includes encryption by default
Faster routing: Simplified packet processing improves speed

Do I Have IPv4, IPv6, or Both?

Most modern networks use dual-stack, meaning your device has both an IPv4 and IPv6 address. This ensures compatibility with older systems while preparing for the future.

To check which IP versions you're using:

Visit WhatsMyInfo.app
Your IPv4 and IPv6 addresses will be displayed instantly
If you see both, you're using dual-stack

Should I Use IPv6?

Yes, if available. Most ISPs and websites now support IPv6, and it offers:

Better performance on compatible networks
Enhanced security with built-in encryption
No need for NAT (Network Address Translation)
Future-proof connectivity

However, IPv4 is still necessary for backward compatibility with older websites and devices.

IPv6 and VPN Compatibility

Not all VPNs support IPv6. If your VPN doesn't route IPv6 traffic, it can create an IPv6 leak — exposing your real location even when connected to the VPN.

Best VPNs with IPv6 support:

ProtonVPN – Full IPv6 support
Mullvad VPN – IPv6 leak protection
NordVPN – Blocks IPv6 leaks by default

Compare VPN features on our Compare VPN Services page, or learn why hiding your IP isn't enough.