Expand IPv6 into eight groups or compress its longest zero run.
Type or paste on the left — the result updates as you type.
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.
Tool page updated: 2026-09-27
