IPv6 notation tool

Expand IPv6 address 21ff:ffff:ffff:0:fff0:0:ffff:ffff

Write any valid IPv6 address in its complete eight-group form for subnetting, binary analysis, logs, and documentation.

Example: 2001:db8::1

Expansion result

Full IPv6 notation for 21ff:ffff:ffff:0:fff0:0:ffff:ffff

Expanded IPv6 address

21ff:ffff:ffff:0000:fff0:0000:ffff:ffff

Compressed IPv6

21ff:ffff:ffff:0:fff0:0:ffff:ffff

Expanded IPv6

21ff:ffff:ffff:0000:fff0:0000:ffff:ffff

IPv6 groups

8 groups of 4 hexadecimal digits

Address size

128 bits

Expansion rules

1An IPv6 address always has eight 16-bit hexadecimal groups.
2Each visible group is left-padded with zeroes until it contains four digits.
3If :: appears, it is replaced with the number of 0000 groups needed to reach eight groups.

Binary representation

Each block below represents one 16-bit IPv6 group. This form is useful when comparing prefix bits or troubleshooting subnet boundaries.

0010000111111111 1111111111111111 1111111111111111 0000000000000000 1111111111110000 0000000000000000 1111111111111111 1111111111111111

Compress this IPv6 address

Recent notation conversions

Open recent IPv6 addresses to inspect their complete eight-group and binary forms.