xn-

Punycode and IDN Converter

Convert internationalized domain names to and from Punycode xn-- notation. Useful for checking non-ASCII hostnames in URLs, DNS, and email.

Runs in your browser ⚡ REST API available 🧩 Embeddable
Output
xn--mnchen-3ya.de

What is Punycode?

Domain names live in ASCII, but Internationalized Domain Names let people register names in their own scripts. RFC 3492 defines Punycode, a deterministic way to encode any Unicode label into ASCII, prefixed with xn--.

Each dot-separated label is encoded independently: café.comxn--caf-dma.com.

When to use an IDN converter

Use this converter to check non-ASCII hostnames before adding them to DNS, URLs, email settings, allowlists, or test data.

Decoding Punycode back to Unicode also helps reveal what an xn-- domain displays as in a browser address bar.

Use the API

Call the same encoder server-side or from another origin. CORS is open, no auth required for the free tier.

curl "https://encode-decode.org/api/v1/punycode\
?action=encode&input=caf%C3%A9.com"