Punycode is a way to encode internationalized domain names (IDN) that contain non-ASCII characters into the ASCII subset supported by DNS. For example, "münchen.de" becomes "xn--mnchen-3ya.de". This tool uses the browser's native URL APIs for reliable encoding. Runs entirely in your browser.
Punycode Encoder / Decoder provides the bridge between human-readable Unicode domains (münchen.de, 例え.jp, 🍕.ws) and the ASCII-only world of DNS. This tool converts in both directions using the browser's native URL parser, which implements the IDNA 2008 / RFC 3492 algorithm - so the output matches what every modern browser actually resolves.
Encoding is per label: each dot-separated chunk is examined, and only those containing non-ASCII code points get the "xn--" prefix and ASCII-Compatible Encoding (ACE). Decoding reverses the process. Pure-ASCII labels pass through unchanged. The encoding is bit-exact and round-trippable, so any string you encode and then decode returns to its original form. This IDN converter ensures your internationalized domain names are compatible with legacy server infrastructure.
Punycode (RFC 3492) is the encoding that lets DNS - which only allows ASCII letters, digits, and hyphens - represent labels containing arbitrary Unicode. Each non-ASCII label is rewritten with the prefix "xn--" followed by an ASCII-Compatible Encoding of the original characters.
The "ü" cannot live in a DNS label, so it is moved to the end as a numeric reference (3ya) while the basic ASCII letters stay in place. The "xn--" prefix tells software the label is encoded and needs decoding before display.
Yes - emoji are just Unicode code points, so they encode the same way. ".ws", ".to", and a handful of other registries actually allow emoji second-level domains; most do not.
Lookalike Unicode characters (Cyrillic "а" vs Latin "a") can produce domains that read identically to a human but resolve to a different server - the so-called IDN homograph attack. Modern browsers display the raw "xn--" form for mixed-script domains to mitigate this.
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