IDN Punnycode converter
Why Punycode exists
The DNS hostname rules historically allowed ASCII only. Punycode encodes Unicode labels as xn-- ASCII strings so münchen.de becomes an ASCII-compatible form registrars and older software can store. This UI labels it "Punnycode" in buttons—what matters is the reversible mapping between human-readable IDN and wire-format ACE strings.
Security note
Homograph attacks mix Cyrillic or Greek lookalikes with Latin to spoof brands. Converting to Punycode exposes the real xn-- label—compare it to your allowlist before trusting a link. Pair with Safe URL checker and URL parser when auditing suspicious hosts.