What is an IDN domain?

An Internationalized Domain Name (IDN) contains non-ASCII characters such as accented letters, Arabic, Chinese, or emoji. IDNs are encoded to Punycode (starting with xn--) for use in the DNS system.

What does xn-- mean in a domain?

xn-- is the ASCII Compatible Encoding (ACE) prefix that signals a Punycode-encoded domain label. For example, münchen.de becomes xn--mnchen-3ya.de.

IDN Encoder / Decoder — Punycode Domain Names

Internationalized Domain Names (IDNs) allow domain names to contain characters from scripts other than the basic Latin alphabet — including Arabic, Chinese, Cyrillic, emoji, and accented European letters. Since the DNS system only supports ASCII characters, IDNs are encoded into a special ASCII-compatible format called Punycode.

What is Punycode?

Punycode is an encoding algorithm that converts Unicode strings to ASCII-compatible representations. Each non-ASCII label in a domain is prefixed with xn-- and followed by the Punycode representation. For example, münchen.de (German for Munich) becomes xn--mnchen-3ya.de in Punycode. Modern browsers automatically display the Unicode version in the address bar while using the Punycode version for DNS resolution.

Why IDN Encoding Matters

Ensures cross-system compatibility with DNS servers that only handle ASCII
Prevents homograph attacks where lookalike Unicode characters mimic legitimate domains
Required when registering non-Latin domain names with registrars
Essential for email routing with international domain addresses

Frequently Asked Questions

Do I need IDN encoding for emoji domains?

Yes. Emoji domains like 🍕.ws must be Punycode-encoded as xn--vi8h.ws before they can be used in DNS and email systems.

Are IDN domains safe?

IDN homograph attacks use look-alike characters (e.g., Cyrillic а vs Latin a) to spoof legitimate domains. Browsers apply various mitigations, and ICANN maintains policies to prevent abuse.

IDN Encoder / Decoder online

Convert international domain names to Punycode (xn--) and back — runs in your browser

What is Punycode?

Why IDN Encoding Matters

Frequently Asked Questions

Do I need IDN encoding for emoji domains?

Are IDN domains safe?