The main difference between IPv4 and IPv6 is in the structure and volume of the address space.
IPv4 uses a 32-bit system, which gives about 4.3 billion unique IP addresses. This amount has long been insufficient for all devices on the Internet. IPv6, by contrast, is based on a 128-bit architecture that provides an almost unlimited number of addresses — more than 340 undecillion (that’s a number with 36 zeros).
In addition to the extended range, IPv6 offers improved security and performance: it supports built-in encryption (IPsec), faster routing, and automatic device configuration (autoconfiguration), which makes it unnecessary to use the NAT used in IPv4.
IPv4 looks familiar — for example, 192.168.0.1, and IPv6 is longer: 2001:0db8:85a3::8a2e:0370:7334. Today, both versions co—exist, but IPv6 is considered the future standard – it was created for the era of IoT, mobile networks and billions of connected devices. If you are still unaware of what is an IP address and how it works – feel free to check our article.
| Category | IPv4 | IPv6 |
|---|---|---|
| Address Length | 32-bit | 128-bit |
| Number of Addresses | ≈ 4.3 billion | ≈ 340 undecillion (3.4 × 10³⁸) |
| Address Format | Numeric, dotted — 192.168.0.1 | Hexadecimal, colon-separated — 2001:0db8:85a3::8a2e:0370:7334 |
| NAT (Network Address Translation) | Required due to address shortage | Not needed — enough addresses available |
| Security (IPsec) | Optional | Built-in by default |
| Autoconfiguration | Limited, usually requires DHCP | Supported natively by the protocol |
| Compatibility | Widely supported, legacy standard | Actively adopted, not yet universal |
| Purpose | Foundation of the old internet | Designed for IoT, mobile, and cloud networks |
What is IPv4 and IPv6?
IPv4 and IPv6 are two generations of Internet protocols that are responsible for devices finding each other on the network. Simply put, it’s like the Internet’s address system. Every computer, phone, or smart kettle should have its own unique IP address, just like a house gets a number on the street.
IPv4 appeared back in the 1980s and remained the standard for a long time. It uses a 32-bit scheme that allows you to create about 4.3 billion unique addresses. At the dawn of the Internet, this seemed more than enough, but as the number of devices grew, there were not enough addresses. To “stretch” the system, they began using NAT technology, which allows multiple devices to share a single IP address.
However, over time, this became insufficient, and IPv6 appeared, a new version of the protocol with 128—bit addressing. This is a huge step forward: more than 340 undecillion addresses are now available, enough for even every atom of a grain of sand. IPv6 also provides higher security, built-in encryption (IPsec), and automatic device configuration.
So IPv4 is an old but still living standard, and IPv6 is its modern, fast and secure replacement, created for the era of the Internet of Things and billions of connected devices. By the way, changing IP address can be crucial in the modern digital world, so it is better to be aware of how to change my IP address.
IPv4 and IPv6: The Internet’s Two Languages Compared
When we talk about the Internet, we rarely think that under the hood of each connection has its own “grammar” — the IP protocol. It determines how devices find each other, how information is transmitted, and how stable the network is. Today there are two versions of this grammar — IPv4 and IPv6. They can be compared as an old, well-known language and a new, more advanced, but not yet mastered everywhere.
The Big Picture — IPv6 and IPv4 as Two Eras of Connectivity
IPv4 is the language of the old Internet, which appeared in the early 1980s. It was created for academic networks and the first computers. It was used to build the entire modern Internet, but it has a serious limitation — only about 4.3 billion addresses. This was enough as long as there were few servers and users on the network.
IPv6, on the contrary, is the language of modern times. It was created with an eye to the Internet of Things, 5G and global connectivity. Its address space is colossal — 340 undecillion addresses. IPv6 has features that make the network not only wider, but also safer, more stable, and smarter.
Figuratively speaking, IPv4 is an old city with narrow streets and a limited number of houses. IPv6 is a new metropolis where there is enough space for every device, and at the same time the roads are wider, the lighting is better, and the security is more reliable.
Core Difference Between IPv4 and IPv6
At the device level, the differences are immediately noticeable:
- Addresses. IPv4 uses a short four—number format (for example, 192.168.1.1), while IPv6 uses a long hexadecimal combination (2001:0db8:85a3::8a2e:0370:7334). This makes IPv6 almost infinite.
- Configuration. IPv4 requires manual configuration or a DHCP server, IPv6 is able to configure itself using SLAAC.
- Speed and routes. Due to the lack of NAT, IPv6 sends data directly, bypassing intermediaries. This reduces latency and improves performance.
- Security. IPv6 has built—in IPsec encryption, which is a mandatory element, not an additional feature, as in IPv4.
Thus, IPv6 is not just an “upgrade”, but a fundamentally new approach: more addresses, fewer intermediaries, more protection.
Adoption, Compatibility, and the Future of IP Evolution
The world is still living in a hybrid of IPv4 and IPv6. The transition to the new system is slow: the old hardware does not always support IPv6, and it is expensive for businesses to rebuild the infrastructure. However, the largest companies — Google, Amazon, Facebook — have long moved to a new standard. IPv6 has become the norm in mobile networks and Asian countries.
For the user, the difference is almost imperceptible — websites and applications just work. But behind the scenes, everything is changing: connections are becoming faster, safer, and more stable. IPv6 is the foundation of the Internet of the future, where every light bulb, sensor and car will receive its own IP.
| Category | IPv4 | IPv6 | Practical Effect |
|---|---|---|---|
| Address Structure | 32-bit numeric (e.g. 192.168.1.1) | 128-bit hexadecimal (e.g. 2001:db8::1) | IPv6 provides exponentially more unique addresses |
| Address Space | ~4.3 billion total | ~340 undecillion total | IPv6 solves the address exhaustion problem |
| Configuration Method | Manual or DHCP required | Automatic via SLAAC | IPv6 devices configure themselves |
| Network Translation (NAT) | Common and necessary | Not required | IPv6 allows direct peer-to-peer communication |
| Routing Efficiency | Slower due to NAT and fragmentation | Streamlined and more direct | IPv6 improves data routing and latency |
| Security Features | Optional IPsec | IPsec is native and mandatory | IPv6 offers stronger built-in encryption |
| Compatibility | Supported by all legacy devices | Supported by modern devices | IPv4 dominates, but IPv6 is rapidly expanding |
| Performance in Mobile Networks | Average | Optimized for mobile and IoT | IPv6 suits 5G and next-gen networks |
| Human Readability | Simple and short | Complex and longer | IPv4 easier for manual use, IPv6 for automation |
| Primary Use Case | Legacy internet infrastructure | Cloud, IoT, and 5G ecosystems | IPv6 is the foundation for the future Internet |
Why the world is switching from IPv4 to IPv6 — the main reasons
- The addresses have run out. IPv4 provides only about 4.3 billion addresses, and there are already many more devices in the world: smartphones, smart speakers, cameras, light bulbs, and IoT. IPv6 solves this problem by offering 340 undecillion unique addresses, which is enough for literally every device on the planet.
- No more NAT. IPv6 gets rid of intermediaries — Network Address Translation. Devices can communicate directly, without “masking” behind a common IP. This means fewer delays, easier setup, and better operation of peer-to-peer services.
- Faster and more efficient. IPv6 is optimized: data packets are transmitted without unnecessary transformations, routes are shorter, and ping is lower. This is especially important for streaming, gaming, and 5G.
- Default security. IPv6 has built—in IPsec encryption protocol, which is mandatory, not optional, as in IPv4. That is, security is enabled out of the box.
- Automatic setting. IPv6 devices can assign an address to themselves (via SLAAC). No need for DHCP, everything connects automatically.
- The Internet of the future. IPv6 is the basis for the Internet of Things, clouds and smart cities. The transition to a new standard is not just an upgrade, but a step towards an endless, secure and scalable Internet.
IPv6 and IPv4 Difference Conclusion
The main difference between IPv4 and IPv6 is in volume and capabilities.
IPv4 was created in the era when the Internet was just emerging. It uses 32-bit addresses — there are about 4.3 billion unique IP addresses in total, which have been missing for a long time.
IPv6 runs on a 128-bit system and offers an almost infinite number of addresses, allowing billions of devices to be connected, from phones to smart fridges.
But it’s not just about quantity. IPv6 is faster, more secure, and more convenient: it supports automatic configuration, more efficient routing, and built-in encryption (IPsec).
Simply put, IPv4 is the Internet of people, and IPv6 is the Internet of everything: smart homes, cars, and future digital ecosystems.
Frequently Asked Questions
Is IPv6 better than IPv4?
Yes, IPv6 is better than IPv4 in several ways, including a larger address pool, built-in security (IPsec), and more efficient routing. IPv6 is designed to handle the internet's future growth, especially with the increasing number of connected devices.
Does IPv6 make internet faster?
IPv6 can lead to faster internet speeds because it eliminates the need for Network Address Translation (NAT) and streamlines routing, making data travel more directly.
Should I enable both IPv4 and IPv6 on my router?
Yes, enabling both IPv4 and IPv6 ensures compatibility with older and newer devices. IPv6 adoption is growing, but IPv4 is still widely used.
What are the disadvantages of IPv6?
1. Compatibility Issues: IPv6 is not universally supported by all devices, networks, or services yet, which can create compatibility challenges. 2. Complexity: IPv6 addresses are longer and more complex, which can be difficult for users to configure or troubleshoot. 3. Transition Period: The shift from IPv4 to IPv6 may cause issues during the transition, as both systems must coexist for now.
