Overview

The IPv4 IPv6 Converter turns any IPv4 address into its IPv6 equivalents using four standard representations. It produces the IPv4-mapped IPv6 form, the full expanded 128-bit form, dotted-decimal mixed notation, and a 6to4 address. Each result can be copied, and an octet breakdown shows the hexadecimal value of every byte.

Common Use Cases

Translating legacy IPv4 addresses for use in IPv6-only environments
Configuring IPv4-mapped addresses on dual-stack servers and applications
Building 6to4 tunnel addresses for automatic IPv6 transition
Understanding how an IPv4 address sits inside a 128-bit IPv6 address
Verifying the hex encoding of each octet for documentation or debugging

How to Use

Enter a valid IPv4 address like 192.168.1.1 in the IPv4 Address field.

Press the Convert button.

Read the four results: IPv4-Mapped IPv6, Full Expanded, Dotted-Decimal Notation, and 6to4 Address.

Use the copy button next to any result to put it on the clipboard.

Press Reset to clear the form and start over.

Check the octet breakdown to see each byte and its 0x hex equivalent.

Example Scenario

Converting a LAN gateway address

Enter 192.168.1.1 and press Convert. The tool shows the IPv4-mapped form ::ffff:c0a8:0101, the full expanded form 0000:0000:0000:0000:0000:ffff:c0a8:0101, the dotted-decimal form ::ffff:192.168.1.1, and the 6to4 address 2002:c0a8:0101::. Each octet appears in the breakdown as 0xc0, 0xa8, 0x01, and 0x01.

Technical Notes

An IPv4-mapped IPv6 address embeds the 32-bit IPv4 address in the low 32 bits of an IPv6 address, preceded by ::ffff. It is defined in RFC 4291 and is the most common way to represent an IPv4 address in IPv6 form.

The full expanded form writes all eight 16-bit groups with leading zeros, producing the complete 128-bit address. It is longer but unambiguous and useful when tools require uncompressed notation.

RFC 4291 also allows the embedded IPv4 address to be written in its familiar dotted-decimal form at the end of the address, such as ::ffff:192.168.1.1.

A 6to4 address uses the 2002::/16 prefix followed by the IPv4 address encoded as two 16-bit hex groups. It is defined in RFC 3056 for tunneling IPv6 over IPv4 networks without a manually configured tunnel.

Each of the four octets is also shown with its hexadecimal equivalent, for example 192 becomes 0xc0. This makes it easy to verify how the address was encoded.

Common Mistakes

Entering an IPv4 address with leading zeros, such as 192.168.01.1, which is rejected as invalid
Expecting the tool to convert IPv6 addresses to IPv4, which it does not do
Confusing the dotted-decimal form ::ffff:192.168.1.1 with the hex form ::ffff:c0a8:0101, both of which are valid and equivalent
Using the 6to4 result on networks that do not support 6to4 tunneling

Frequently Asked Questions

Both encode the same address. The full expanded form writes all eight 16-bit groups with leading zeros, while the IPv4-mapped form compresses the zeros and uses ::ffff. They are interchangeable representations of the same 128-bit address.

The IPv4 octets are converted to hex: 192 becomes c0, 168 becomes a8, 1 becomes 01, and 1 becomes 01. Two octets are then paired into each 16-bit group.

IPv4-mapped addresses are primarily used by dual-stack implementations to represent IPv4 sockets. Whether they work depends on the operating system and application.

6to4 (RFC 3056) allows IPv6 traffic to travel through a tunnel over an IPv4 network by embedding the IPv4 address in the 2002::/16 prefix. It is a transition mechanism that does not require a manually configured tunnel.

IPv4 IPv6 Converter

Overview

Common Use Cases

How to Use

Example Scenario

Converting a LAN gateway address

Technical Notes

Ipv4 Mapped

Full Expanded

Dotted Decimal

Six To Four

Octet Breakdown

Common Mistakes

Frequently Asked Questions

What is the difference between the full expanded and IPv4-mapped forms?

Why does 192.168.1.1 become c0a8:0101?

Can I use the IPv4-mapped address to connect to an IPv4 service?

What is a 6to4 address used for?

Related Topics