IPv4 vs IPv6: What’s the Difference?
2026-01-21
IPv4 vs IPv6: What’s the Difference?
IPv4 and IPv6 are two versions of the Internet Protocol (IP) used to identify devices and route data across the internet. While they serve the same purpose, they differ greatly in design, capacity, and future readiness.
Understanding the difference between IPv4 and IPv6 helps you better understand modern networking, internet scalability, and why IPv6 adoption is increasing worldwide.
What Is IPv4?
IPv4 (Internet Protocol version 4) is the original and most widely used IP standard.
Example IPv4 address:
192.168.1.1
Key features of IPv4:
- 32-bit address space
- About 4.3 billion unique addresses
- Written in decimal format
- Uses NAT extensively to conserve addresses
IPv4 has powered the internet for decades, but its limited address space has become a major constraint.
What Is IPv6?
IPv6 (Internet Protocol version 6) was developed to replace IPv4 and solve address exhaustion.
Example IPv6 address:
2001:0db8:85a3:0000:0000:8a2e:0370:7334
Key features of IPv6:
- 128-bit address space
- Virtually unlimited IP addresses
- Written in hexadecimal format
- Designed for modern and future networks
IPv6 enables direct, end-to-end connectivity without relying heavily on NAT.
IPv4 vs IPv6: Side-by-Side Comparison
| Feature | IPv4 | IPv6 |
|---|---|---|
| Address length | 32-bit | 128-bit |
| Address format | Decimal | Hexadecimal |
| Address space | ~4.3 billion | ~340 undecillion |
| NAT required | Yes | No (by design) |
| Header complexity | Simple | Simplified but extensible |
| Security | Optional | Built-in IPsec support |
Why Was IPv6 Created?
The rapid growth of:
- Smartphones
- Cloud services
- IoT devices
- Global internet usage
quickly exhausted available IPv4 addresses.
IPv6 was created to:
- Provide massive address scalability
- Improve routing efficiency
- Simplify network configuration
- Support modern internet architecture
Are IPv4 Addresses Still Used?
Yes. IPv4 is still widely used today.
To cope with address shortages, networks rely on:
- NAT (Network Address Translation)
- Carrier-grade NAT (CGNAT)
- IP address sharing
This is why many users still have IPv4-only or dual-stack connections.
IPv6 Advantages Over IPv4
IPv6 offers several important benefits:
- 🚀 Larger address space
- 🔒 Improved security support
- 🌐 Better routing efficiency
- 📡 No need for NAT in most cases
- ⚙️ Easier auto-configuration
These advantages make IPv6 better suited for the future internet.
Why Isn’t IPv6 Fully Adopted Yet?
Despite its benefits, IPv6 adoption has been gradual due to:
- Legacy IPv4 infrastructure
- Compatibility concerns
- Cost of upgrading systems
- Slow ISP and enterprise adoption
As a result, most networks today operate in dual-stack mode, supporting both IPv4 and IPv6.
Which One Am I Using?
Your device may use:
- IPv4 only
- IPv6 only
- Both IPv4 and IPv6
This depends on your ISP, network configuration, and device support.
Online IP tools can instantly detect:
- Your active IP version
- IPv4 and IPv6 availability
Will IPv4 Be Replaced by IPv6?
IPv6 is the long-term future of the internet, but IPv4 will not disappear overnight.
Both protocols will likely coexist for many years, with IPv6 gradually becoming dominant as adoption increases.
Summary
IPv4 and IPv6 serve the same purpose but differ significantly:
- IPv4 is limited and legacy
- IPv6 is scalable and future-proof
- Both are still in use today
Understanding IPv4 vs IPv6 helps you make sense of modern internet connectivity and prepares you for future network technologies.
IP Web Tools allows you to check whether you are using IPv4 or IPv6 and analyze detailed IP information instantly.