Convert internationalized domain names (IDN) between Unicode and ASCII Punycode (xn--). Useful for IDN homograph analysis, DNS, and email. Runs entirely in your browser.
xn-- + Punycode (RFC 3492); ASCII labels are unchanged.Convert internationalized domain names between Unicode and ASCII Punycode (xn--). Useful for DNS, email, and IDN homograph / phishing analysis. Runs in your browser.
Domain names can only use ASCII letters, digits, and hyphens at the DNS level, so internationalized domain names (IDNs) with accents or non-Latin scripts are encoded into an ASCII form called Punycode, prefixed with `xn--`. For example, münchen.de becomes xn--mnchen-3ya.de. This tool converts in both directions - Unicode to Punycode (ToASCII) and Punycode back to Unicode (ToUnicode) - per dot-separated label, entirely in your browser.
Input:
münchen.de
Output:
xn--mnchen-3ya.de
What is Punycode used for?
It lets internationalized domain names (with non-ASCII characters) be represented in the limited ASCII character set that DNS supports, using an xn-- prefix.
How does this help spot phishing?
Attackers register lookalike domains using non-Latin characters that render identically to real ones (IDN homograph attacks). Converting a suspicious domain to its xn-- form reveals whether it is actually the legitimate ASCII domain or an impostor.
Does it normalize the input?
Yes - non-ASCII labels are Unicode NFC-normalized before encoding, which matches how registrars and browsers process them. It does not perform full UTS-46 mapping.
Is anything sent to a server?
No. The Punycode algorithm runs entirely in your browser; nothing is uploaded.