(Dokumentation på engelsk)
What it does
The IPv4 ↔ IPv6 Converter translates between IPv4 and IPv6 addresses in both directions, entirely in your browser. Paste any address and it auto-detects the family, then shows the canonical RFC 5952 form, the fully expanded form, IPv4-mapped (::ffff:a.b.c.d) and IPv4-compatible representations, and any IPv4 embedded inside an IPv6 address. Everything runs 100% client-side - your input never leaves the page.
How to use it
- Type an IPv4 (
192.168.1.1) or IPv6 (2001:db8::1) address into the box - the family is detected automatically. - For an IPv4, read its IPv4-mapped and IPv4-compatible IPv6 forms. Optionally enter a custom /96 prefix (e.g.
64:ff9b::) to embed it under a NAT64-style prefix. - For an IPv6, read its canonical compressed form, its fully expanded form, and any IPv4 embedded in a mapped/compatible address.
- Copy any result, or Copy share link to send the exact input and prefix to a teammate.
Examples
IPv4 → IPv6 (mapped & compatible)
Input: 192.168.1.1
IPv4-mapped IPv6: ::ffff:192.168.1.1
IPv4-compatible IPv6: ::192.168.1.1
Under prefix 64:ff9b::: 64:ff9b::192.168.1.1IPv6 → canonical & expanded
Input: 2001:db8::8a2e:370:7334
Canonical (RFC 5952): 2001:db8::8a2e:370:7334
Expanded: 2001:0db8:0000:0000:0000:8a2e:0370:7334Extract an embedded IPv4
Input: ::ffff:10.0.0.1 → Expanded 0000:0000:0000:0000:0000:ffff:0a00:0001, Embedded IPv4 10.0.0.1.Good to know
- Shareable: your address and prefix are encoded in the URL (
?a=…&p=…), so a link reproduces the exact view. - Private: all parsing and conversion happen locally - safe for real network addresses.
- RFC 5952: IPv6 output uses lowercase hex, no leading zeros, and collapses the longest run of zero groups to
::. Only::ffff:mapped addresses render with a dotted-decimal tail; the deprecated compatible range renders as pure hex. - Related tools: Subnet & CIDR Calculator,
Base64Base64An encoding representing binary data as 64 safe ASCII characters, so it survives transport through text-only channels. It encodes — it does not encrypt.
, JSON Formatter.