IPv6 Expander / Compressor

The IPv6 Expander / Compressor is a free browser-based tool that converts IPv6 addresses between their expanded (full) and compressed (shorthand) forms. Enter any valid IPv6 address in either notation and instantly see both representations, along with the binary form, address type, scope, and whether the address is an IPv4-mapped IPv6 address.

IPv6 addresses consist of eight groups of four hexadecimal digits separated by colons (e.g., 2001:0db8:0000:0000:0000:0000:0000:0001). The compressed notation removes leading zeros within groups and replaces the longest consecutive run of all-zero groups with :: (e.g., 2001:db8::1). This tool handles both directions automatically.

The tool also provides a batch mode for converting multiple addresses at once, and includes a reference panel of common IPv6 addresses such as the loopback (::1), link-local (fe80::), multicast, unique local, and well-known DNS server addresses.

If you work with IPv4 subnets, try the Subnet Calculator for CIDR and network calculations. For converting between number systems, the Number Base Converter can help with hex-to-binary and other base conversions. For DNS configuration, check out the DNS Record Generator.

All processing runs entirely in your browser. No IP addresses or network data are ever sent to any server. This tool is safe to use with production infrastructure addresses.

1. Enter an IPv6 address in the input field (compressed or expanded form).
2. The tool auto-detects the format and displays both expanded and compressed forms instantly.
3. Review the Binary Representation to see each group's 16-bit binary value.
4. Check the Address Information section for the address type (Global Unicast, Link-Local, Multicast, etc.) and scope.
5. Use the Copy button next to any field, or press Ctrl+Shift+C to copy all results at once.
6. Switch to Batch Mode to convert multiple IPv6 addresses at once, one per line.
7. Click the Reference button to see common IPv6 addresses and click any to use it as input.