IPv4 and IPv6 are two versions of the protocol that allows devices to communicate on the Internet. IPv4 remains widely used, but IPv6 was created to address the shortage of available addresses and simplify the evolution of the global network.
Key takeaways
- IPv4 uses short addresses like 192.168.1.1.
- IPv6 uses much longer addresses in hexadecimal.
- IPv6 offers a virtually inexhaustible number of addresses.
- Both protocols still coexist on the Internet.
What is IPv4?
IPv4, or Internet Protocol version 4, is the historical format of IP addresses. An IPv4 address consists of four numbers separated by dots, for example 154.67.244.210. Each number ranges from 0 to 255, giving approximately 4.3 billion possible addresses.
This volume seemed enormous at the beginning of the Internet, but became insufficient with the arrival of smartphones, connected devices, cloud services and mobile networks. To extend IPv4 usage, operators use techniques such as NAT or CGNAT.
What is IPv6?
IPv6 uses 128-bit addresses, written in hexadecimal groups separated by colons. An example IPv6 address is 2001:0db8:85a3::8a2e:0370:7334. This format allows an enormously greater number of addresses than IPv4.
IPv6 was designed to facilitate the assignment of unique addresses, simplify certain aspects of routing and reduce dependence on NAT. Its deployment is progressing, but many networks still use IPv4 in parallel.
IPv4 vs IPv6 comparison table
| Criterion | IPv4 | IPv6 |
|---|---|---|
| Format | 4 decimal numbers | Hexadecimal groups |
| Example | 192.168.1.1 | 2001:db8::1 |
| Size | 32 bits | 128 bits |
| Availability | Limited | Very broad |
Why hasn't IPv6 completely replaced IPv4 yet?
The transition takes time because operators, businesses, network equipment and applications all need to be compatible. Many services today operate on dual stack, meaning with both IPv4 and IPv6 enabled simultaneously.
For the user, this coexistence is generally invisible. Your connection may use IPv6 for some services and IPv4 for others depending on the configuration of your operator and the site visited.
Conclusion
IPv4 remains indispensable, but IPv6 represents the logical future of the Internet. Understanding the difference helps to better interpret the information displayed by an IP lookup tool and to diagnose certain network problems.
How to use this guide in practice
To use this guide on IPv4 and IPv6 reliably, start by checking the context of your connection: home network, mobile network, company network, VPN, proxy or server. The same result can mean different things depending on the exit point being used. IP information should therefore be read together with other clues, such as provider, ASN, country, address type and DNS settings.
Avoid jumping to conclusions. Many network data points are approximate, shared or dependent on a third-party provider. If you are troubleshooting, note the test time, network used, VPN state and browser involved. These details make comparisons more useful and help separate a real issue from a normal routing effect.
Quick checklist
- Compare the IPv4 and IPv6 result on two different networks if possible.
- Run the test again after enabling or disabling a VPN, proxy or private DNS.
- Note whether the address is residential, mobile, business, hosted or shared.
- Do not treat an IP address as proof of identity without technical and legal context.
This checklist turns an isolated lookup into a reproducible diagnosis. It is especially useful when two tools show different results or when a service blocks a connection without explaining the reason clearly.
FAQ
Is IPv6 faster than IPv4?
Not automatically. Performance mainly depends on the network, operator, routing and service visited.
Should I disable IPv6?
In general, no. It is better to leave it enabled unless there is a specific technical issue or instruction from your network administrator.
Why do I still have an IPv4?
Because many services and networks still use IPv4. The transition to IPv6 is gradual.