IPv6 to IPv4 Converter
Paste an IPv6 address and get the IPv4 embedded inside it. Not every IPv6 address carries one, so the converter reads the five formats that do.
The converter tells you which of the five formats you pasted, and does the whole job in your browser, so nothing you paste leaves your machine.
If you came here to turn IPv6 off on your computer or router, that is a network setting rather than an address conversion, and no converter can do it. This tool reads an address you already have; it does not change how your device connects.
How to Convert IPv6 to IPv4
- Enter your IPv6 address in the field above.
- Press Convert to IPv4. The tool identifies which address type you pasted and reads the IPv4 out of it.
- Copy your result. Alongside the IPv4 address you get its type, so you know which addressing or transition mechanism produced the embedded IPv4.
Addresses can be written short or fully expanded. Both work.
Which IPv6 Addresses Can Be Converted to IPv4
Most converters read only the IPv4-mapped and 6to4 forms. This one reads five, because IPv4 addresses ended up inside IPv6 in more places than those two, and each format comes from a different addressing or transition mechanism. These are the five the converter supports, not every format ever defined.
| Address type | Starts with | What it usually means |
|---|---|---|
| IPv4-mapped | ::ffff: | A dual stack machine noting down an IPv4 visitor |
| 6to4 | 2002: | A site tunnelling IPv6 over IPv4, with its public IPv4 written into the prefix |
| NAT64 | 64:ff9b::/96 | The IPv4 server an IPv6-only client reaches through a NAT64 gateway |
| IPv4-compatible | :: then the address | An early transition format, now deprecated |
| Teredo | 2001:0000: | A client tunnelling out from behind NAT |
Teredo returns extra detail. The format stores the client's mapped IPv4 address and mapped UDP port in obfuscated form, and our converter decodes them for you.
IPv6 to IPv4 Conversion Examples
Pick any of these to run it through the converter above. The examples use IPv4 addresses from the documentation ranges defined in RFC 5737, so none of them belong to a real host or server.
| Input | Result |
|---|---|
| 192.0.2.1, IPv4-mapped | |
| 192.0.2.1, IPv4-mapped | |
| 192.0.2.55, 6to4-style documentation example | |
| 198.51.100.23, NAT64 | |
| 198.51.100.7, IPv4-compatible | |
| 203.0.113.45, Teredo |
In the Teredo example, the server address 203.0.113.10 sits in plain hex in the third and fourth groups (cb00:710a). The client's address and port are the hidden part: both are stored with every bit flipped, and they decode to 203.0.113.45 and port 40000. As with the other rows, these values sit in documentation space and do not point at a real Teredo server or client.
Why Some IPv6 Addresses Cannot Be Converted to IPv4
Our converter says so in plain words rather than returning a number that looks believable and is wrong. Two addresses get a direct answer instead: ::1 is the IPv6 loopback, whose IPv4 counterpart is 127.0.0.1, and :: means no address at all, the same as 0.0.0.0.
Reading an address that uses the NAT64 well-known prefix is not the same as running NAT64. The embedded IPv4 address represents an address in the IPv4 namespace, typically the destination in common NAT64 deployments, and it is not necessarily the client that originated the connection. Teredo works differently: it encodes the client's mapped IPv4 address and UDP port in obfuscated form. Either way, the converter only extracts the values already encoded in the address, it does not perform NAT64 translation or establish who generated the traffic.
IPv6 to IPv4 Converter Use Cases
Your access logs are the most common reason people land here. A log holds ::ffff:198.51.100.7 while every filter you wrote expects 198.51.100.7. One visitor, two spellings, and rules that quietly miss.
Firewall rules fail the same way. You banned an IPv4 address and the traffic kept coming. If your server hands that address to your code in mapped form, the ban never matched it in the first place.
NAT64 and Teredo addresses both encode an IPv4 address inside an IPv6 one, though what that address represents differs. Extracting it, and for Teredo the mapped port as well, gives you a concrete address to check against your own records instead of an opaque IPv6 string.
A 2002: address contains the IPv4 address associated with its 6to4 prefix, which can help when documenting inherited equipment configured long before you got there. It does not confirm the tunnel is still active.
Frequently Asked Questions
For location, ISP, and network data on any address you decode, see our IP Geolocation API.