By Debmedia Technologies LLP · Kolkata, India · Updated
What Is IPv6 to IPv4 Conversion?
IPv6 to IPv4 conversion means reading the IPv4 address that some IPv6 addresses carry inside. A normal IPv6 address, such as one assigned by your provider, has no IPv4 equivalent. Only special transition formats hold an IPv4 address in their bits, and this tool recognises them.
You may meet these addresses in logs, in firewall output or when you debug a dual-stack server. Knowing the hidden IPv4 address lets you identify the real visitor or host.
How to Use This IPv6 to IPv4 Converter
- Enter an IPv6 address, such as ::ffff:192.0.2.33 or 2002:c000:0221::1.
- Press Convert.
- Read the embedded IPv4 address and the type of IPv6 address.
- If nothing is embedded, the tool explains what kind of address you entered.
Where the IPv4 Address Hides
| Format | Prefix | Where the IPv4 bits are |
|---|---|---|
| IPv4-mapped | ::ffff:0:0/96 | The last 32 bits |
| IPv4-compatible (deprecated) | ::/96 | The last 32 bits |
| NAT64 | 64:ff9b::/96 | The last 32 bits |
| 6to4 | 2002::/16 | Bits 17 to 48, right after the 2002 |
| Teredo | 2001::/32 | The server in bits 33 to 64, and the client in the last 32 bits, with all bits flipped |
The structure of these prefixes follows RFC 4291, the IPv6 addressing architecture.
Common Situations
Your logs show ::ffff: addresses
This is normal for a server that listens on both protocols. The visitor is using IPv4, and the IPv4 address is the part after ::ffff:. The tool also converts the hexadecimal version, such as ::ffff:c000:0221.
The address is a regular global address
If it starts with 2001, 2400, 2600 or similar and is not a transition prefix, it cannot be converted. Use the IPv6 owner lookup to see who owns it, or find its hostname with the reverse DNS tool.
The address is very long
Make it easier to read with the compression tool or see every group with the expansion tool. To go back to IPv6, use the IPv4 to IPv6 converter.
All calculations run in your browser, and nothing you type is uploaded.
Why the Conversion Sometimes Fails
If the tool reports no embedded IPv4 address, nothing is wrong with your input. Global IPv6 addresses assigned to devices are unrelated to any IPv4 address, even when the same device also has one. The only way to learn the IPv4 address of such a host is to look up its name, or to ask the owner.
Be careful with 6to4 and Teredo results as well. They show the address of a tunnel endpoint, which may be a router or a relay and not the real device. Treat them as a clue, not as proof of identity, and check the owner with a lookup before acting.
Frequently Asked Questions
Disclaimer: results come from live requests and can change as records and servers change. We cannot guarantee that every answer matches what every visitor sees.