IPv4 vs IPv6 Explained
The Main Differences Between IPv4 and IPv6
IPv4 vs IPv6 is a comparison of two versions of the Internet Protocol, the rules that define how addresses are written and how packets travel. IPv4 is the older version and still carries most internet traffic. IPv6 was designed as its successor and uses longer addresses, which gives it a far larger pool of possible addresses.
An IPv4 address is 32 bits long and is written as four decimal numbers separated by dots, such as 192.0.2.10. That allows about 4.3 billion unique addresses. An IPv6 address is 128 bits long and is written as eight groups of hexadecimal digits separated by colons, such as 2001:db8::10. The number of possible addresses is so large that it cannot practically run out in normal use. The shortage that pushed the change is described in the article on IPv4 exhaustion.
Design Changes That Affect Routing and Setup
IPv6 simplifies the packet header and removes features that were rarely used, which makes routing more efficient. It also drops the broadcast method of reaching every device on a network and relies on more targeted messages instead.
Address configuration differs too. IPv6 devices can configure their own addresses from the network prefix announced by the router, a method called stateless address autoconfiguration, or they can obtain addresses from a DHCPv6 server. Because the address space is so large, IPv6 is designed without the need for network address translation, which many IPv4 networks use to share one public address among many devices.
Most modern systems run both protocols at once, which is called dual-stack operation. A dual-stack device can reach IPv4 and IPv6 sites, and the connection used depends on what each site offers and how the network routes traffic.
What IPv6 Means for a Hosted Website
For a website, IPv6 support shows up in DNS. A site with an IPv4 address publishes an A record. To be reachable over IPv6, the server also needs an IPv6 address, and the domain needs an AAAA record pointing to it. Visitors whose networks support IPv6 can then connect over it, while others continue to use IPv4.
Not every host offers IPv6 by default, so it is worth checking whether a hosting plan provides IPv6 addresses and whether the control panel allows AAAA records. A site that supports only IPv4 still works for most visitors, but it is unreachable for clients that have only IPv6 connectivity.
A Dual-Stack Shop in Practice
A small online shop has a server with one IPv4 and one IPv6 address. Its DNS includes an A record and an AAAA record for the same name. A visitor on a network that supports IPv6 receives the AAAA answer and connects over IPv6, while a visitor on an older connection receives the A answer and connects over IPv4. The shopper sees the same site in both cases.
Frequently asked questions
Do I need IPv6 for my website?
Not strictly, but it is increasingly useful. IPv4 still works for most visitors, and a site that publishes only IPv4 addresses remains reachable. Adding IPv6 means publishing an AAAA record and having an IPv6 address on the server. It lets visitors on IPv6-only networks reach the site without relying on translation.
Does IPv6 make a website faster?
Not by itself. IPv6 changes addressing and routing, not the speed of the server or the page. Some connections may be faster over IPv6 because they follow a shorter or less congested path, but the difference depends on the network. Page size, server response time and caching matter far more for speed.