IPv6 notation tool

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

Compressed IPv6 address

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

Expanded IPv6

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

Compressed IPv6

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

Expanded length

39 characters

Compressed length

20 characters

Characters saved

19

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 2 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

Recent notation conversions

Recent IPv6 Compressions

Open recent IPv6 addresses to compare their expanded and shortest standard forms.

Learn the rules for compressing IPv6 addresses