Expand a compressed IPv6 address

Expand compressed IPv6 notation into eight four-digit hexadecimal groups.

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ToolIPv6 Expander
Input
Output
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How it works

A compressed address is split at ::, zero groups are inserted until eight 16-bit groups exist, and every group is padded to four hexadecimal digits. Without ::, exactly eight groups must already be present.

  • Eight 16-bit groups represent 128 bits.
  • Only :: can stand for multiple zero groups.

Worked example

Expand 2001:db8::1 to full notation
Expand a compressed IPv6 address to all 8 groups with binary representation
Input
											2001:db8::1
Output
												Input: 2001:db8::1
Expanded: 2001:0db8:0000:0000:0000:0000:0000:0001
Groups: 2001, 0db8, 0000, 0000, 0000, 0000, 0000, 0001
Binary: 0010000000000001:0000110110111000:0000000000000000:0000000000000000:0000000000000000:0000000000000000:0000000000000000:0000000000000001
Total bits: 128

When to use this

Logs, network lessons, and configuration reviews expand IPv6 text.

Edge cases

  • Two :: tokens are ambiguous and invalid.
  • An IPv4 dotted tail contributes two groups.
  • Seven explicit groups plus :: inserts one zero group.

References