IPv6 Expand

Expand a shortened IPv6 address to its full form. Paste an address that uses :: or dropped leading zeros and the tool writes out all eight groups with four hex digits each. Free and instant in your browser.

When you need to expand an IPv6 address or uncompress the :: shorthand back into its full, written-out form, this tool does it in one step. It takes a compressed address, restores the all-zero groups the :: stood for, and pads every group to four hex digits, so you get the complete eight-group form with no shorthand left. Developers and network admins reach for this to write out an IPv6 address in long form for exact string matching, to feed an unambiguous address to older software, or just to see all eight 16-bit groups laid out. It even handles an address with an embedded IPv4 tail such as ::ffff:192.0.2.5.

Read the guide: How to Expand an IPv6 Address
Full form
2001:0db8:0000:0000:0000:ff00:0042:8329
All eight groups, four hex digits each, with :: and leading zeros restored.
Full form2001:0db8:0000:0000:0000:ff00:0042:8329
Compressed2001:db8::ff00:42:8329

How it works

  1. 1

    Paste the short address

    Enter an IPv6 address such as 2001:db8::ff00:42:8329.

  2. 2

    Read the full form

    The tool restores the :: zero groups and pads every group to four digits.

  3. 3

    Copy the result

    Copy the full eight-group address, with the compressed form shown for reference.

Instant & 100% private — nothing is uploaded

Everything runs locally in your browser. Your code, text and files are processed on your own device and are never sent to a server — so there are no upload waits, no size limits from us, and nothing is ever stored or logged.

Frequently asked questions

How do I expand an IPv6 address by hand?
Replace the :: with enough all-zero groups to bring the total back to eight, then pad each group to four hex digits with leading zeros. So 2001:db8::ff00:42:8329 expands to 2001:0db8:0000:0000:0000:ff00:0042:8329. The :: stood for three zero groups here, because six groups were already written.
How many groups does :: stand for?
As many all-zero groups as are needed to make eight groups in total. Count the groups written on each side of the ::, add them, and subtract from eight. A full IPv6 address always has exactly eight 16-bit groups.
Is the expanded address different from the short one?
No. Expanding only restores the zeros that compression removed; the 128-bit value is identical, so the two forms are interchangeable. The expansion runs entirely in your browser.
Can it expand an address with an embedded IPv4?
Yes. A trailing dotted-quad such as ::ffff:192.0.2.5 is parsed correctly, with the IPv4 part converted to its two hex groups in the full form.

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