IPv4 vs IPv6: What’s the Difference?

Published: 7 Apr 2025

The internet relies on IP (Internet Protocol) addresses to identify devices and allow them to communicate. Two versions of IP addresses exist: IPv4 and IPv6. While IPv4 has been around since the early days of the internet, IPv6 was introduced to solve some of its limitations. These versions differ in address structure, speed, security, and capability.

In this article, we’ll explore the key differences between IPv4 and IPv6 to help you understand which one is better for today’s internet needs.

Table of Content

✅ Quick Comparison Table: IPv4 vs IPv6

Here is a quick comparison table of IPv6 vs IPv4:

Feature	IPv4	IPv6
Address Length	32-bit	128-bit
Address Format	Decimal (e.g., 192.168.1.1)	Hexadecimal (e.g., 2001:db8::1)
Number of Addresses	~4.3 billion	~340 undecillion
Security	Relies on external tools	Built-in IPsec encryption
Speed	Good but limited by NAT	Faster with better routing
NAT Requirement	Required	Not required
Configuration	Manual/DHCP	Automatic (SLAAC)
Adoption Rate	Very high	Still growing

Key Differences between IPv4 and IPv6

Let’s discuss the key differences between IPv6 and IPv4 in detail to better understand:

1. Address Format

IPv4 and IPv6 use different formats to identify devices.

IPv4:

Uses a 32-bit address format.
Written in decimal format (e.g., 192.168.0.1).
Provides around 4.3 billion unique addresses.
Simple and widely supported.
Easier to read and remember.

IPv6:

Uses a 128-bit address format.
Written in hexadecimal format (e.g., 2001:0db8:85a3::8a2e:0370:7334).
Can generate over 340 undecillion addresses.
Better suited for future internet growth.
More complex but very scalable.

2. Speed and Performance

The performance of each protocol can differ depending on the network.

IPv4:

Works well in current networks with fast processing.
Can experience delays due to NAT (Network Address Translation).
Not optimized for newer network structures.
Better on older infrastructure.
Sometimes faster in certain configurations.

IPv6:

Eliminates the need for NAT, improving speed.
Better performance in peer-to-peer connections.
More efficient routing and data flow.
Designed for better mobility and scalability.
Slightly faster in modern networks.

3. Security Features

IPv6 was built with stronger security in mind.

IPv4:

Security depends on external tools like firewalls.
No built-in encryption or authentication.
More vulnerable to spoofing and DDoS attacks.
Relies on manually configured security protocols.
Can be secured, but requires extra work.

IPv6:

Built-in IPsec for data encryption and authentication.
Better protection against packet tampering.
Reduces attack surface with no NAT requirement.
Supports end-to-end encryption by default.
Stronger built-in security features.

4. NAT (Network Address Translation)

How each protocol handles multiple devices sharing one IP.

IPv4:

Requires NAT due to limited address availability.
Translates one public IP to many private ones.
Can slow down connections and complicate networking.
Common in homes and small networks.
Makes peer-to-peer communication harder.

IPv6:

No need for NAT thanks to a vast number of IPs.
Each device gets its own unique IP.
Simplifies network configuration and communication.
Makes end-to-end communication easier.
Enhances transparency between devices.

5. Compatibility and Adoption

Adoption varies depending on the environment.

IPv4:

Universally supported by all devices and systems.
Works with all routers, websites, and servers.
Still widely used despite limitations.
Transitioning slowly to IPv6.
More familiar to IT professionals.

IPv6:

Supported by most modern devices and systems.
Still not as widely used as IPv4.
Requires updated hardware and software.
Slowly growing in adoption worldwide.
May cause compatibility issues in older setups.

6. Address Configuration

How each protocol assigns and manages IPs.

IPv4:

Uses manual or DHCP configuration.
Needs regular maintenance and management.
More prone to human error.
Static IPs can be harder to manage.
Relies on central servers for IP assignment.

IPv6:

Supports auto-configuration using SLAAC.
Devices can generate their own addresses.
Reduces admin workload and errors.
More flexible and dynamic.
Better suited for large networks.

Which is Better: IPv4 or IPv6?

When deciding between IPv4 and IPv6, it depends on your specific needs and network environment. IPv4 is still widely used, easy to implement, and compatible with almost every device. It’s ideal for networks that don’t require a huge number of addresses or advanced features.

IPv6 is clearly the future. It offers a massive number of unique IP addresses, improved performance, stronger security, and simpler configuration in modern systems. If you’re building a new network or planning for the future, IPv6 is the better choice due to its scalability and advanced capabilities.

In summary:

Use IPv4 if you need compatibility and are working with older systems.
Choose IPv6 if you’re setting up modern infrastructure and want better security, speed, and scalability.

Conclusion

IPv4 has served the internet well for decades, but its limitations are becoming more apparent as more devices connect online. IPv6 is the modern solution that offers better scalability, security, and performance. However, adoption is still in progress, and many systems continue to rely on IPv4. For new infrastructure and future-proofing, IPv6 is the better choice, but both will continue to coexist for some time. Your decision should depend on your network needs, hardware compatibility, and long-term goals.

❓ FAQs about IPv4 and IPv6

Here are some of the most FAQs related to IPv4 and IPv6:

Why was IPv6 created?

IPv6 was created to overcome the limited address space in IPv4 and provide better performance, security, and scalability for modern internet usage.

Can I use both IPv4 and IPv6 together?

Yes, many systems use a dual-stack approach where both IPv4 and IPv6 run together to ensure compatibility and gradual transition.

Is IPv6 more secure than IPv4?

Yes, IPv6 has built-in security features like IPsec for encryption and authentication, making it more secure by design.

Why is IPv6 adoption slow?

IPv6 adoption is slow due to compatibility issues, cost of upgrading hardware, and the widespread use of IPv4 in existing networks.

Will IPv6 replace IPv4 completely?

Eventually, yes, but it will take time. Both protocols will coexist for years until IPv6 becomes the dominant standard.

Does IPv6 improve internet speed?

In some cases, yes. IPv6 can reduce latency and improve performance by removing the need for NAT and simplifying routing.

Do all devices support IPv6?

Most modern devices do, but older hardware or outdated systems may not support IPv6 without upgrades.

What is SLAAC in IPv6?

SLAAC stands for Stateless Address Autoconfiguration, a feature that allows IPv6 devices to generate their own IP addresses automatically.

How can I check if I’m using IPv6?

You can check your IP version using online tools or by looking at your network settings in your device’s control panel.

Is IPv6 required for the internet to grow?

Yes, because IPv4’s limited address space cannot support the growing number of internet-connected devices.