Convert tools

IPv6 Expand / Compress

Expand IPv6 into eight groups or compress its longest zero run.

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Uses RFC 5952-style lowercase and leftmost longest-run compression. Zone IDs and dotted IPv4 suffixes are unsupported.

Up to 100,000 UTF-16 units per input and 1,000,000 per result. See the supported formats and examples below.

How to use

  1. Expand IPv6 into eight groups or compress its longest zero run.
  2. Choose the mode or options, then run the tool.
  3. Review the result, then copy or download the TXT file.

Example

2001:db8::1 → 2001:0db8:0000:0000:0000:0000:0000:0001

Details and limitations

Uses RFC 5952-style lowercase and leftmost longest-run compression. Zone IDs and dotted IPv4 suffixes are unsupported.

Text stays in your browser; it is not sent to a conversion server.

FAQ

IPv6 Expand / Compress — What are the supported inputs and limits?

Uses RFC 5952-style lowercase and leftmost longest-run compression. Zone IDs and dotted IPv4 suffixes are unsupported.

Format references

Tool page updated: