IPv4 to IPv6 Converter
Convert IPv4 addresses to IPv6-mapped or 6to4 — and extract IPv4 from IPv6.
Convert any IPv4 address to its IPv4-mapped IPv6 form (::ffff:a.b.c.d), the fully expanded form, and the 6to4 prefix (2002::/16). The reverse direction extracts the embedded IPv4 from a mapped or 6to4 IPv6 address.
Common use cases
- Map IPv4 server addresses into IPv6 logging or audit pipelines
- Generate a 6to4 prefix when bootstrapping IPv6 connectivity over IPv4
- Recognise an IPv4-mapped address in dual-stack server logs
- Educate yourself on IPv4/IPv6 transition mechanisms with concrete examples
Frequently asked questions
What's the difference between mapped and 6to4?▾
IPv4-mapped (::ffff:a.b.c.d) is used inside dual-stack hosts to represent IPv4 connections in an IPv6 socket API. 6to4 (2002::/16) is a transition mechanism for tunnelling IPv6 over IPv4.
Why does the expanded form have 0000s?▾
IPv6 addresses are 128 bits / 8 hextets. The first 80 bits are zero in the IPv4-mapped scheme, then ffff, then the IPv4 packed into the last 32 bits.
Can I extract IPv4 from any IPv6?▾
Only from IPv4-mapped (::ffff:) or 6to4 (2002:) addresses. Native IPv6 addresses do not embed an IPv4.
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