Convert between an IPv6 unique local address (fd00::/8) and an embedded IPv4 — the last 32 bits of the ULA, the same convention used when a ULA plan mirrors an existing v4 range — plus subnet math and IP geolocation.
Example rows are pre-filled — replace them with your own.
| IPv6 ULA | IPv4 | Status |
|---|
Example rows are pre-filled — replace them, and the prefix, with your own.
| IPv4 | IPv6 ULA | Status |
|---|
| IP↕ | Hosting↕ | Country↕ | Region / City↕ | ISP / Org↕ | ASN↕ | Timezone↕ | Status |
|---|
An IPv6 unique local address (fd00::/8) can embed a full IPv4 address in its last 32 bits — the same convention used when a ULA numbering plan is designed to mirror an existing v4 range. This tool reads or writes those last two hextets as a dotted-decimal IPv4 address; nothing else in the address is touched.
Subnet math (network address, broadcast address, usable host range, and usable host count) follows standard IPv4 CIDR rules, including the /31 and /32 edge cases where the usable count equals the total rather than total − 2. The suggested ULA alternative embeds the same range using the convention above.
Each address is resolved by a third-party IP-to-location lookup service and mapped to approximate country, region, ISP, and coordinate data. Results reflect the network's registered location — typically an ISP or hosting provider's address — not a precise physical location, and accuracy varies by provider and region.