IPv6 notation tool

Compress IPv6 address 21da:0000:0000:0000:00ff:0000:0000:9c5a

Convert any valid IPv6 address to its shortest standard notation by removing redundant zeroes safely.

Example: fe80:0000:0000:0000:0202:b3ff:fe1e:8329

The conversion runs locally. No external lookup service is used.

Compression result

Shortest IPv6 notation for 21da:0000:0000:0000:00ff:0000:0000:9c5a

Compressed IPv6 address

21da::ff:0:0:9c5a

Expanded IPv6

21da:0000:0000:0000:00ff:0000:0000:9c5a

Compressed IPv6

21da::ff:0:0:9c5a

Expanded length

39 characters

Compressed length

17 characters

Characters saved

22

Compression rules

How IPv6 compression works

  1. 1Leading zeroes are removed from every four-character hexadecimal group.
  2. 2The longest sequence of two or more 0000 groups can be replaced once with ::.
  3. 3Hexadecimal letters are written in lowercase for a consistent canonical form.

This address

Zero-group analysis

The expanded address contains a longest uninterrupted sequence of 3 zero groups. That sequence is eligible for the :: abbreviation.

Compressed notation is useful in configuration files, logs, command output, and URLs. It represents exactly the same 128-bit address as the expanded form.

Expand this IPv6 address

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