IPv6 Compressor and Expander
Expand IPv6 into eight full groups or compress it using RFC 5952 rules. IPv4-mapped addresses use a dotted-decimal tail in the compressed output.
Processing happens in this page without contacting the entered address. Tool pages do not load ads or analytics; inputs are not saved or added to the page URL.
How to use this tool
Enter an IPv6 literal to see eight four-digit groups and a shorter canonical spelling. The longest zero run is compressed; the leftmost run wins a tie. A single zero group stays visible. IPv4-mapped addresses use a dotted-decimal tail.
2001:0db8:0000:0000:0000:0000:0000:0001 → 2001:db8::1