How it works
This converter takes an IPv4 address and represents it in IPv6 format, showing the IPv4-mapped (::ffff:192.0.2.1) and IPv4-compatible variants, as well as the expanded and compressed notations of a single IPv6 address.
It helps you understand how an IPv4 fits within the IPv6 space and to switch between the long and short forms of an address without messing up the zeros and hexadecimal groups.
Use cases
- Get the IPv4-mapped form of an IPv4 for configurations or records that require it.
- Convert an IPv6 from its compressed notation to the expanded one to see it in full.
- Validate that an IPv6 address is well-formed before using it in a configuration.
- Understand how an IPv4 maps within the IPv6 address space.
Frequently asked questions
What is an IPv4-mapped address?
It is an IPv6 with the format ::ffff:a.b.c.d that represents an IPv4 within the IPv6 space. Dual-stack network stacks use it to handle IPv4 connections through IPv6 sockets.
What is the difference between compressed and expanded notation?
The expanded one writes all eight full four-digit groups. The compressed one omits the leading zeros of each group and replaces a single sequence of zero groups with ::, giving a shorter form of the same address.
Can I use :: more than once in an address?
No. The double colon can only appear once, because otherwise it would be ambiguous how many zero groups each occurrence represents. A second occurrence makes the address invalid.
Does the conversion let me browse over IPv6 with an IPv4?
No. The conversion is a representation of the address, not a transport mechanism. For IPv4 traffic to travel over IPv6, transition techniques such as NAT64 or tunnels are needed, which operate on the network.