Punycode / IDN Converter

Convert internationalized domains between Unicode and ASCII (xn--) form.

Free • no sign-up • runs entirely in your browser.

What is Punycode?

DNS only understands ASCII, so internationalized domain names (IDNs) with accents or non-Latin scripts are encoded into an ASCII form that starts with xn-- — called Punycode. For example münchen.de is stored as xn--mnchen-3ya.de. Browsers convert back to the readable Unicode form for display.

Security: homograph attacks

Attackers register lookalike domains using characters that resemble Latin letters (e.g. a Cyrillic “а”). Converting a suspicious domain to Punycode reveals its true ASCII form — a quick way to spot these spoofs.

Frequently asked questions

What does xn-- mean?

It's the standard prefix marking a Punycode-encoded (ACE) label. Everything after it is the ASCII encoding of the Unicode label.

Why do I see xn-- in my browser?

Browsers sometimes display the Punycode form instead of Unicode when a domain mixes scripts, as an anti-spoofing measure.

Is this conversion done online?

No — the conversion runs entirely in your browser with a local implementation of RFC 3492. Nothing is sent anywhere.