IPv4 to IPv6 Converter
Convert an IPv4 address to its IPv4-mapped IPv6, IPv4-compatible and 6to4 representations with the correct hexadecimal encoding.
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Convert an IPv4 address into IPv4-mapped, compatible and 6to4 IPv6 representations.
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Convert IPv4 addresses into IPv6 forms
There are several standard ways to represent an IPv4 address inside the larger IPv6 address space, and this tool generates each of them. The IPv4-mapped form, written with the prefix colon-colon-ffff, is used when an IPv6-only application needs to communicate with an IPv4 host. The deprecated IPv4-compatible form embeds the address directly after a zero prefix. The 6to4 form builds a 2002 prefix from the address, historically used for tunnelling IPv6 over IPv4 networks.
Each representation encodes the thirty-two bits of the IPv4 address as two sixteen-bit hexadecimal groups, which the converter calculates precisely.
When these conversions are needed
Dual-stack networks, where IPv4 and IPv6 run side by side, rely on mapped addresses so that software can handle both protocols through a single interface. Engineers reading logs or socket output often encounter the colon-colon-ffff form and need to recognise the IPv4 address hidden inside it. The 6to4 prefix appears in older tunnelling setups.
The IPv4-compatible and 6to4 mechanisms are largely historical and now discouraged, but understanding them helps when maintaining legacy systems. All conversion happens locally in your browser, with no lookups.
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Frequently Asked Questions
What is an IPv4-mapped IPv6 address?
It is an IPv6 address of the form ::ffff:a.b.c.d that represents an IPv4 host, letting IPv6 software communicate with IPv4 systems.
Why is the IPv4-compatible form deprecated?
The IPv4-compatible format, with a plain zero prefix, was an early transition mechanism that has been superseded by the mapped form and other techniques.
What is a 6to4 address?
It uses a 2002 prefix built from an IPv4 address to tunnel IPv6 traffic across IPv4 networks. It is now largely historical.
How is the IPv4 address encoded in IPv6?
Its thirty-two bits are split into two sixteen-bit groups and written in hexadecimal, which form the last part of the IPv6 address.
Can I convert IPv6 back to IPv4?
Only mapped and compatible forms contain a recoverable IPv4 address. This tool focuses on producing the IPv6 representations from an IPv4 input.
Privacy & Security
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How to Use
Enter an IPv4 address to see its IPv6 equivalent forms.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
Related Tools
Port Scanner
NetworkCheck which common ports respond on a host and understand what each exposed service means. Scan only systems you are authorised to test.
DNS Misconfiguration
NetworkAnalyze DNS records (TXT, SPF) for security gaps.
TLS Compat Tester
NetworkCheck client-server compatibility for TLS versions.