IPv4 vs. IPv6: What’s the Difference and Which to Use?

The strain on the internet’s aging infrastructure is starting to show, especially when it comes to IPs. The familiar IPv4 system, once more than sufficient, is now running out of room. IPv6 steps in as the long-term solution, offering an almost limitless address space along with built-in security features and more efficient routing. In this article, we’ll break down the key differences between IPv4 and IPv6, explore what IPv6 brings to the table, and look at the practical challenges of making the transition.

TL;DR

IPv4 and IPv6 are protocols that connect devices online. IPv4 uses 32-bit addresses, but is running out of space. IPv6, with 128-bit addresses, offers more space, better security, and faster routing. Moving to IPv6 takes time due to compatibility issues, but it’s key to the internet’s future growth.

Why IPv4 vs. IPv6 matters

Each connected device, whether it's a smartphone, computer, smart TV, or even an IoT gadget, relies on an IP to function. Without an IP, devices would never be able to identify one another, let alone establish connections on the internet.

IPv4 has powered the internet since the 1980s, but it simply wasn’t built for today’s billions of connected devices, IoT systems, and cloud infrastructures. IPv6 was designed to fix that, bringing near-limitless address space, built-in security, and better routing efficiency.

Understanding how IPv4 and IPv6 differ isn’t just a tech trivia question. It matters to businesses, developers, and data teams building scalable systems that need to stay relevant in an evolving internet architecture.

What is an IP address?

An IP (Internet Protocol) address is a set of numbers (or numbers and letters) provided by your ISP (Internet Service Provider) and assigned to any device. It allows devices to communicate with other devices and networks. Without an IP, it wouldn’t be possible to connect to anything online.

In a nutshell, IPv4 and IPv6 are both versions of the same IP address. For the most part, it’s essentially the same thing, but at the same time, some key differences make IPv6 stand out from the crowd, and we’ll explore them soon.

IPv4: the original protocol

Developed in the 1980s, IPv4 (Internet Protocol version 4) became the backbone of the modern internet. It uses 32-bit numeric addresses, meaning it can generate roughly 4.3B unique IPs. At first, that seemed infinite. But as the internet exploded with more users, more devices, more everything, that number started to look small. Approaches like Network Address Translation (NAT) were introduced to make multiple devices share one IP, extending IPv4’s lifespan.

IPv4 remains popular because it’s simple, reliable, and universally supported. Nearly every system, router, and data center understands how to deal with it, making it the safe, battle-tested choice even decades later.

However, businesses and developers may find that using IPv4 proxies can still help scale and maintain privacy and security in their systems, especially with legacy systems continuing to be in operation. For anyone looking to increase anonymity while scraping or browsing, IPv4 proxies can offer reliable solutions.

IPv6: the next generation

In the 1990s, IPv6 (Internet Protocol version 6) was introduced to bypass the limitations of IPv4, particularly the lack of available IP addresses. IPv6 uses 128-bit alphanumeric addresses, allowing for approximately 340Un unique IPs, enough to give every grain of sand on Earth its own address (and still have plenty left).

Beyond just more space, IPv6 introduces technical improvements:

• Better security: IPsec encryption is built in.
• Faster routing: simplified header structure improves efficiency.
• Automatic configuration: devices can connect and assign addresses themselves.
• No need for NAT: every device can have a unique, public-facing IP.

Despite its advantages, IPv6 adoption is still growing slowly due to compatibility challenges and the cost of upgrading infrastructure.

As businesses look to scale, especially with IoT and high-traffic applications, using residential proxies or datacenter proxies alongside IPv6 offers enhanced speed and scalability. These proxies are especially valuable in environments that require large-scale data scraping or automation, where they help ensure smoother operations, more efficient routing, and better access to geo-restricted content.

Technical differences explained

IPv6 isn’t just "IPv4 with more space." It’s a more advanced, future-proof protocol.

Its simplified header structure reduces latency, improves packet delivery, and supports multicasting, allowing a single packet to reach multiple devices simultaneously. This makes IPv6 ideal for streaming, real-time data delivery, and automation.

On the security front, IPv6 supports IPsec, providing authentication, integrity, and encryption by design. IPv4 can also use IPsec, but it’s optional, which is why many IPv4 networks still rely on third-party firewalls or VPNs.

Real-world adoption: why the transition is slow

While IPv6 is clearly the future, the transition from IPv4 hasn’t been smooth. Many businesses continue to use IPv4 because:

• Legacy infrastructure upgrades can be costly.
• Some devices and applications don’t fully support IPv6 yet.
• ISPs must run both versions side by side (dual-stack mode), which adds complexity.

According to Google’s IPv6 adoption statistics, global usage surpassed 45% in 2025, showing steady progress, but full replacement could still take years.

Security and performance: myths and facts

Myth 1: IPv6 is faster than IPv4 by default.

Fact: Speed depends on configuration and routing. IPv6 can be faster when properly optimized, but not always automatically.

Myth 2: IPv6 is less secure because it’s new.

Fact: IPv6 was designed with security in mind, including built-in encryption through IPsec.

Myth 3: IPv4 will soon be obsolete.

Fact: The coexistence of IPv4 and IPv6 will persist for a long period as the transition process unfolds gradually.

Use cases: gaming, IoT, VPNs, and home networks

• Gaming. IPv6 can lower latency and reduce NAT-related connection issues, giving players smoother, more stable matches.
• IoT. With billions of smart devices coming online, IPv6’s massive address pool keeps things scalable and efficient.
• VPNs and proxies. IPv6 improves routing and supports modern proxy infrastructure, improving privacy and bypassing geo-blocks.
• Home networks. IPv6’s auto-configuration simplifies setup while offering direct device communication without NAT complications.

Conclusion

IPv4 has carried the internet for more than 40 years, powering everything from email servers to global data centers. But it’s reaching its limit. IPv6 steps in with a virtually infinite address pool, built-in security, and streamlined performance. The shift won't take place right now. Compatibility issues, hardware limitations, and cost barriers mean IPv4 will stick around for a while. Still, IPv6 adoption is only a matter of time, so the earlier people, businesses, and ISPs get ready, the easier the transition will be.

Together, IPv4 and IPv6 are keeping the digital world connected while paving the way for a faster, safer, and more scalable internet.