Punycode / IDN Converter
Convert internationalised domain names between Unicode and Punycode (xn--) form, one per line. Nothing is uploaded — the conversion runs locally.
| Input | Unicode | Punycode (ACE) |
|---|
Punycode Converter
Domain names can use letters well beyond ASCII, but the domain system itself only carries a limited set of characters. Punycode (RFC 3492) bridges the two: it represents a label's non-ASCII characters using only letters, digits and hyphens, prefixed with xn--. So münchen.de becomes xn--mnchen-3ya.de. This tool converts a domain both ways, label by label.
How it works
- Each label is converted separately, so a name is handled the same way the domain system handles it.
- A Unicode name produces its
xn--ASCII form; anxn--name produces its Unicode form. - Labels longer than 63 characters, or with invalid characters, are reported per line.
- Plain ASCII names are returned unchanged.
Related tools
This tool is about domain labels and their ACE form. The Unicode converter handles characters and code points, and the query string parser handles percent-encoding in URLs — three different jobs.
Frequently asked questions
What does this tool do?
It converts internationalised domain names between their readable Unicode form and their ASCII (Punycode) form with the xn-- prefix, one domain per line.
Is anything uploaded?
No. The conversion runs entirely in your browser.
What is Punycode?
Punycode is the encoding defined in RFC 3492 that represents non-ASCII characters in a domain label using only letters, digits and hyphens, so the name can travel over systems limited to ASCII.
What does xn-- mean?
A label beginning with xn-- is an ASCII-Compatible Encoding (ACE) label: the xn-- prefix marks it as a Punycode-encoded internationalised label.
How is this different from the Unicode converter?
The Unicode converter turns characters into code points and escapes; this tool works at the domain-label level, between a name and its ACE form. A percent-encoded URL is a different matter again, handled by the query string parser.
Are similar-looking domains a risk?
Yes. Different scripts can contain similar-looking characters, which is used in IDN homograph attacks; two domains can look alike while being different names.
Related: the Unicode converter, query string parser, or browse every browser-only tool on the all tools page.