Punycode encode/decode

The DNS system historically only supports ASCII characters, so domain names with Cyrillic, CJK, or other non-ASCII characters (IDN) are encoded as Punycode — an ASCII-compatible form prefixed with xn--. This tool encodes and decodes such domains.

How to use it

• Encode: enter a domain with Cyrillic or other Unicode characters (e.g. пример.рф) to get its ASCII form as xn--....
• Decode: paste a domain in xn--... form to see the original characters.
• Works on both a single domain label and a full multi-level domain name.

Common uses

• Checking what real domain is hiding behind a confusing xn--... string in an email or link.
• Registering or setting up DNS for a domain with national characters when the registrar requires an ASCII form.
• Spotting a homograph attack — a domain visually mimicking a known brand using characters from a different script.

Things to keep in mind

Visually similar characters from different scripts (like Cyrillic "а" and Latin "a") can form a domain that looks identical to a known brand — this is the basis of homograph phishing.

Not every browser shows decoded Unicode the same way: when a domain label mixes scripts, browsers often deliberately show the raw xn-- form as a warning sign.