IPv6 Compression & Expansion

Paste any IPv6 address in either form to see both its compressed and expanded representations.

IPv6 address (either form)

Compressed (RFC 5952)2001:db8::1

Expanded2001:0db8:0000:0000:0000:0000:0000:0001

How to read the result

RFC 5952: suppress leading zeros per group, replace the longest run of 2+ zero groups with :: once (first run wins ties), use lowercase hex.

Example

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

FAQ

When is :: allowed?

Once per address, replacing one or more consecutive all-zero groups.

Why lowercase?

RFC 5952 recommends lowercase hex for consistent display.

Is my input sent anywhere?

No. Conversion runs entirely in your browser.