If you’ve ever looked at your computer’s network settings and noticed an IP address, you may have wondered what those numbers and letters actually mean. An IP address identifies a device on a network and helps data find its way to the correct destination.
Today, there are two major versions of the Internet Protocol in use: IPv4 and IPv6. While both perform the same basic job, they use very different addressing systems.
The biggest difference between IPv4 and IPv6 is the size and format of their addresses. IPv4 uses a 32-bit address, while IPv6 uses a much larger 128-bit address.
This difference gives IPv6 access to an enormous number of unique addresses and helps solve the address shortage associated with IPv4.
In this guide, we’ll break down the difference between IPv4 and IPv6, explain how each works, compare their features, and show you how to identify and configure them on a Windows PC.
Difference Between IPv4 and IPv6 [Quick Table]
| Feature | IPv4 | IPv6 |
| Full Name | Internet Protocol version 4 | Internet Protocol version 6 |
| Address Size | 32-bit | 128-bit |
| Address Format | Decimal numbers | Hexadecimal characters |
| Example | 192.168.1.10 | 2001:db8:85a3::8a2e:370:7334 |
| Number of Addresses | About 4.3 billion | About 340 undecillion |
| Address Separation | Periods (.) | Colons (:) |
| Broadcast | Supported | Not supported |
| Address Configuration | Manual or DHCP | Manual, DHCPv6, or automatic configuration |
| NAT | Commonly used | Generally less necessary |
| Security | IPsec support | IPsec support |
| Header | More complex | Simplified base header |
| Current Usage | Still widely used | Growing adoption |
Difference Between IPv4 and IPv6 [Complete Guide]
To understand the difference between IPv4 and IPv6, remember that IPv4 uses a 32-bit address system written as four decimal numbers, while IPv6 uses a 128-bit address system written with hexadecimal characters separated by colons.
IPv6 provides vastly more addresses, supports more efficient network configuration, and was designed to address limitations of IPv4.
1: Understand What an IP Address Does
Before comparing IPv4 and IPv6, it helps to understand what an IP address actually does.
An IP address works somewhat like a mailing address for a device connected to a network. When your computer sends information across the Internet, the network needs an address that identifies where that information should go. The IP protocol provides this addressing and routing system.
For example, an IPv4 address might look like 192.168.1.25. Your router can use addresses like this to identify devices on your local network.
IPv6 performs the same fundamental function, but its address format is completely different. An IPv6 address can look like 2001:db8:85a3::8a2e:370:7334.
The important thing to remember is that IPv4 and IPv6 are different versions of the same Internet Protocol family. IPv6 was developed primarily because the available IPv4 address space was becoming insufficient.
2: Understand How IPv4 Addresses Work
IPv4, or Internet Protocol version 4, uses a 32-bit addressing system. These 32 bits are divided into four groups of 8 bits, known as octets.
An IPv4 address is normally written using four decimal numbers separated by periods. For example:
192.168.1.100
Each number can range from 0 to 255. Because IPv4 has 32 bits, it can theoretically provide approximately 4.3 billion unique addresses.
That sounded like an enormous number when IPv4 was originally designed. However, the Internet eventually grew to include billions of computers, smartphones, servers, smart TVs, cameras, and other connected devices.
Technologies such as NAT, or Network Address Translation, helped extend the usefulness of IPv4 by allowing multiple devices to share a public IP address. However, NAT adds complexity to network communication.
3: Understand How IPv6 Addresses Work
IPv6, or Internet Protocol version 6, uses a 128-bit addressing system. That’s dramatically larger than IPv4’s 32-bit system.
IPv6 addresses are written using eight groups of hexadecimal characters, separated by colons.
For example:
2001:0db8:85a3:0000:0000:8a2e:0370:7334
IPv6 also allows addresses to be shortened. Consecutive groups containing zeros can often be compressed using ::.
So the address above can become:
2001:db8:85a3::8a2e:370:7334
The massive address space is IPv6’s biggest advantage. It provides approximately 340 undecillion possible addresses, which is an extraordinarily large number.
This makes IPv6 much better suited for a world where practically every device can have network connectivity.
4: Compare IPv4 and IPv6 Address Formats
The easiest way to recognize IPv4 and IPv6 is to look at their formats.
An IPv4 address uses decimal numbers and periods, such as 10.0.0.1.
An IPv6 address uses hexadecimal characters and colons, such as fe80::1a2b:3c4d:5e6f.
IPv6 hexadecimal characters can include the numbers 0 through 9 and letters A through F.
You don’t need to memorize IPv6 formatting to use it. Windows, routers, and other network equipment handle most of the technical details automatically.
5: Check Whether Your Windows PC Uses IPv4 or IPv6
You can easily check the IP versions configured on your Windows computer.
Go to Settings > Network & internet > Wi-Fi or Ethernet > Hardware properties. Depending on your Windows version and connection type, you’ll see network information that can include your IPv4 address and IPv6 address.
You can also use Command Prompt.
Go to Start > type Command Prompt > Open, then enter:
ipconfig
Look for the IPv4 Address and IPv6 Address entries.
If both appear, your computer is configured to use both protocols. This is common because many modern networks support dual-stack networking, allowing IPv4 and IPv6 to operate together.
6: Understand the Difference in Address Availability
One of the biggest reasons IPv6 was created is the limited number of IPv4 addresses.
IPv4 provides roughly 4.3 billion addresses, but not all of those addresses are available for public Internet devices. Some address ranges are reserved for private networks, special purposes, and other uses.
IPv6 dramatically expands the available address space.
With 128 bits, IPv6 provides an almost unimaginably large number of possible addresses. This makes it possible to assign unique addresses to huge numbers of devices without relying as heavily on techniques such as NAT.
This is particularly important as the number of IoT devices, mobile devices, cloud systems, and connected equipment continues to grow.
7: Compare IPv4 and IPv6 Network Configuration
IPv4 commonly relies on DHCP, or Dynamic Host Configuration Protocol, to automatically provide devices with network configuration.
IPv6 can use SLAAC, or Stateless Address Autoconfiguration, allowing devices to configure their own addresses based on information provided by the network.
IPv6 can also use DHCPv6 when centralized configuration is required.
Go to Settings > Network & internet > Advanced network settings > More network adapter options. Right-click your network adapter and select Properties to see options such as Internet Protocol Version 4 (TCP/IPv4) and Internet Protocol Version 6 (TCP/IPv6).
Don’t disable either protocol simply because you don’t recognize it. Modern Windows networking may rely on both.
8: Understand NAT and IPv6
NAT is extremely common in IPv4 networks. It allows multiple devices on a private network to share a public IPv4 address when communicating with the Internet.
For example, your laptop, phone, smart TV, and other devices can have private IPv4 addresses inside your home while your router uses a public IPv4 address for Internet communication.
IPv6 was designed with enough addresses that this approach is generally less necessary.
That doesn’t mean IPv6 automatically makes every network faster. IPv6 and IPv4 performance depends on the network, ISP, routing, hardware, and configuration. The primary advantage of IPv6 is its larger address space and modern networking capabilities, not simply speed.
9: Understand IPv4 and IPv6 Compatibility
IPv4 and IPv6 aren’t directly interchangeable. A device using only IPv4 cannot simply communicate with an IPv6-only destination without some form of translation or compatibility mechanism.
That’s why many networks use dual stack, where devices and network equipment support both IPv4 and IPv6.
This approach allows users to access services that are available through either protocol while networks gradually transition toward broader IPv6 adoption.
For most home users, this transition happens behind the scenes. Your operating system, router, and Internet service provider handle much of the process automatically.
FAQs
Is IPv6 better than IPv4?
IPv6 is more modern and provides a vastly larger address space, but that doesn’t mean IPv4 is useless. IPv4 remains heavily used across the Internet, while IPv6 adoption continues to grow.
Is IPv6 faster than IPv4?
Not necessarily. IPv6 can provide networking advantages, but actual performance depends on your ISP, routing, network hardware, server, and configuration.
Can I use IPv4 and IPv6 at the same time?
Yes. This is called dual-stack networking, and it’s widely used to allow devices to communicate using either protocol.
How do I know whether my PC supports IPv6?
Most modern versions of Windows support IPv6. Go to Settings > Network & internet > Advanced network settings > More network adapter options, then open your adapter’s properties and look for Internet Protocol Version 6 (TCP/IPv6).
Does IPv6 replace IPv4?
IPv6 was designed as the long-term successor to IPv4, but IPv4 has not disappeared. Both protocols continue to coexist.
Does IPv6 eliminate the need for a router?
No. IPv6 still uses routers to connect different networks and forward packets toward their destinations.
Which protocol should I use on Windows?
For most users, the best approach is to leave IPv4 and IPv6 enabled unless you have a specific networking reason to change the configuration.
Summary
The primary difference between IPv4 and IPv6 is their addressing capacity and format. IPv4 uses a 32-bit address written with decimal numbers and periods, while IPv6 uses a 128-bit address written with hexadecimal characters and colons.
IPv4 remains an important part of today’s Internet, but its limited address space has created the need for technologies such as NAT. IPv6 addresses this limitation with an enormous address space and provides modern mechanisms for network configuration and communication.
For everyday Windows users, you usually don’t need to choose between the two manually. Keeping IPv4 and IPv6 enabled allows your computer to work with networks and services that support either protocol.
Understanding how both work, however, makes troubleshooting network problems much easier and gives you a better picture of how your Internet connection actually works.