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IPv4 vs IPv6: Examining the Pros, Cons, and Differences

There are two main versions of IP addresses. But which is better: IPv4 vs IPv6? 🤔

IPv4, the “old” standard, has been around for many decades and has served us well. However, the internet has grown, and it’s now facing some serious challenges.

That’s where IPv6, the new generation, comes in. It promises to address some of the challenges faced by IPv4. But is new always better?

Below, we’ll explore the differences between IPv4 and IPv6 to help you answer this important question.

📚 Table of contents:

First, what is IP?

Before we compare IPv4 vs IPv6, we have to first talk about IP itself.

IP stands for Internet Protocol. You can think of it as how online data is transferred and received.

Every device we connect to the internet with (e.g., computers, printers, smartphones, tablets, etc.) is assigned a unique IP address, and the protocol (IP) helps these devices communicate with each other.

So, just like humans have languages we use to communicate, our devices also need a standard protocol (i.e., IP) to communicate.

For example, let’s say you want to email your co-worker. You’d compose the email and add a recipient email address and subject.

After clicking “Send,” your email client (e.g., Gmail), will take the email, break the data down into small chunks, and determine the IP addresses of the sender and the recipient (yours and your co-worker’s).

Then, your operating system will send out the data from the email. As the data travels across the internet, it’ll pass through different routers and networks before finally landing in your co-worker’s email server.

Once it arrives, the data is reassembled into the correct order (think putting together a puzzle) and then delivered to your co-worker’s inbox.

This, in a nutshell, is how IP works. 🔧

💡 If you’d like a more thorough explanation, check out our article on what an IP address is.

What is IPv4?

The “v” from IPv4 stands for “version.”

As we compare IPv4 vs IPv6, it’s important to note that IPv4 is the first and older IP version.

When IPv4 first came onto the scene in the ‘80s, the developers couldn’t have known how significant the internet would eventually be.

One of the newest technologies, IoT (Internet of Things), is a good example.

In a nutshell, IoT helps to connect physical devices over the internet and allows them to communicate with each other and be controlled remotely.

This is common in a smart home setup where a smart thermostat can communicate with the lights to adjust their brightness based on the temperature, or alert your smartphone if the security camera detects unusual activity.

All of these smart devices need their own unique IP address, which IPv4 is increasingly struggling to accommodate. This is due to its address format, which we’ll discuss in a moment.

While it does have its limitations, most of the internet connections today still use IPv4.

IPv4 address format ⚙️

If you’re like most people, your website, laptop, or other device probably has an IPv4 address, or you’ve at least seen it before.

It is a 32-bit address that’s made up of four sets of numbers. These sets are separated by periods.

For example, an IPv4 address can look like this:

Each of these sets can range from 0 to 255, and this allows for around 4.3 billion unique addresses.

The challenge here is that there are currently 5.18 billion internet users, and we know that one person can connect multiple devices to the internet [1]. With more people getting connected and purchasing various devices, we can safely assume that this number will continue to grow. Hence the struggle to support IoT technology.

Advantages and disadvantages of IPv4 👍👎

For us to make an informed IPv4 vs IPv6 comparison, we have to look at the pros and cons of each. First up, IPv4.

Advantages of IPv4

  • Most devices are compatible with IPv4. This makes it easy for us to buy a new device, get an IPv4 address, and get connected, seamlessly.
  • IPv4 is deeply ingrained in the infrastructure of the internet. This makes it a stable and reliable option because most networks, routers, and software applications were developed with it in mind.

Disadvantages of IPv4

  • Limited address space. Simply put, we’re running out of available IPv4 addresses.
  • NAT (Network Address Translation) was introduced to help with the shortage of addresses. This allows for multiple devices to share one IP address. The challenge with NAT is that it can cause problems with some applications.

Now that we have a good understanding of IPv4 let’s discuss the newest IP version.

IPv4 vs IPv6 represented in a visual format as sets of dual-colored wires interconnecting with one another.

What is IPv6?

IPv6 is the newer version of IP addresses, and it was introduced in the ‘90s.

It was specifically developed to help address some of the limitations of IPv4. In that regard, it provides a larger pool of unique IP addresses to accommodate the rapidly growing number of devices that are connected via the internet.

In addition to addressing the IP address shortage, it offers advantages like improved security features, a simplified network configuration, and better support for emerging technologies like IoT.

IPv6 address format ⚙️

The IPv6 address is very different from the IPv4 one. Instead of four sets of numbers, it has eight. It is also a 128-bit format that includes both numbers and letters.

For example, an IPv6 address might look like this:


Some addresses can also have consecutive groups of zeros. These are abbreviated using a double colon (::).

For example, instead of having an address like this:


The continuous zeros can be omitted using the double colon like this:


Advantages and disadvantages of IPv6 👍👎

This IPv4 vs IPv6 battle continues as we take a closer look at some of the pros and cons that may come from choosing IPv6.

Advantages of IPv6

  • A large address space. According to its format, IPv6 can accommodate around 340 undecillion unique addresses! That’s 340 with 36 zeros after it.
  • IPv6 has built-in security features, like IPsec, which provides encryption and authentication at the network level.
  • Better correlation with emerging technologies. If you’ll be using the IoT, IPv6 seamlessly supports this.

Disadvantages of IPv6

  • Compatibility with existing IPv4 infrastructure. Since most of the internet and the structures around it (networks, servers, etc.) were built with IPv4 format in mind, it’s important for companies that wish to switch to IPv6 to carefully plan this transition.
  • There’s a bit of a learning curve. Technicians and network administrators would need to get some training on how to properly integrate the system seamlessly into the existing network.
A glowing desktop monitor with internet of Things (IoT) devices surrounding it - which are also glowing.

IPv4 vs IPv6: Key differences

To be able to fully grasp what each IP brings to the table, it’s best to put these versions up, side by side.

Address length32-bit IP address128-bit IP address
Address formatFour sets of numbers, separated by dotsEight sets of numbers and letters, separated by colons
Example of address192.168.10.1502001:0db8:85a3:0001:0000:8a2e:0370:7338
Number of unique IP addresses available43 billion340 undecillion (i.e., 340 trillion trillion trillion!)
Address ModesUses systems of classes and NAT to manage addressesUses a simpler addressing structure and eliminates the need for NAT
SecurityLacks built-in security features. It, therefore, relies on additional protocols for encryption and authenticationIncludes IPsec as a standard feature, providing encryption and authentication by default
IoT compatibilityLimitations to support the growing number of IoT devicesDesigned to accommodate the growing number of IoT devices
Network configurationNeeds manual configuration or DHCP servers to assign IP addressesSupports autoconfiguration, allowing devices to generate their own unique IP addresses without manual configuration or DHCP servers
MobilityNot designed with mobile devices in mind, so it’s not suitable for them.Supports autoconfiguration, allowing devices to generate their own unique IP addresses without manual configuration or DHCP servers

Which one is more popular? 📢

IPv4 is more popular than IPv6. This is because IPv4 has been around much longer than IPv6. It is also widely supported by devices and networks.

Another factor to consider is that although many online businesses, brick-and-mortar stores, nonprofit organizations, and others with an online presence may be interested in transitioning to IPv6, the process can be challenging because the two protocols aren’t directly compatible.

These companies and organizations need time to update their systems to support IPv6. As a result, IPv4 remains more popular for now. But the transition to IPv6 is gradually happening to address the need for more IP addresses [2].

Which is faster? 🚀

In terms of speed, the battle of IPv4 vs IPv6 is tight.

For example, Sucuri ran tests on websites with IPv4 vs websites with IPv6 addresses and concluded that “IPv4 and IPv6 performances are pretty much equal” [3].

That being said, there are some tests that favored IPv6 for speed, but this depends on multiple variables [4].

Remember that the speed of data transfer mostly depends on factors such as bandwidth, network infrastructure, and network congestion, not IP address.

Which one has built-in Quality of Service (QoS) capabilities? 🖱️

QoS refers to the ability to prioritize certain types of network traffic. This can help time-sensitive or critical data receive preferential treatment.

IPv6 has a built-in QoS ability that allows it to assign different priority levels to data. For example, it can assign “high priority” for real-time apps like video conferencing apps while assigning “low priority” to non-time-sensitive activities like downloading files.

While IPv4 can implement QoS using additional protocols, it isn’t a built-in feature.

IPv4 vs IPv6: Which is the better option?

From the above information, we hope you’ve learned a thing or two about these two protocols. Ideally, you also understand that each one has its own advantages and disadvantages.

IPv4 has been the backbone of the internet for many years, providing many unique IP addresses that we needed to connect, receive, and transfer information.

However, the way the internet has grown at an incredible rate over the past decade or so, the number of unique addresses that IPv4 has to offer is simply not enough. While it did try to address this challenge with the introduction of NAT, there are still some technical issues that prevent it from being as efficient as it needs to be.

IPv6 is heading in the right direction in addressing all the challenges that arose from IPv4. In addition to providing a lot more unique addresses, it also offers additional built-in security and QoS features. Based on this, to decide the winner in our IPv4 vs IPv6 battle, we’re leaning more toward the new IP version in town: IPv6.

👉 Sure, at the moment, IPv4 is still the more popular choice (by default, really), but in due time, IPv6 has the potential to overtake it by a large margin. We’ll just have to wait and see.

Now that you understand the difference between IPv4 vs IPv6, you might want to learn the difference between domains and subdomains.