Punycode / IDN Converter

Punycode / IDN Converter

Local Processing

Convert internationalised domain names to Punycode (xn--) and back.

How It Works & Processing Standards

Convert internationalised domain names to Punycode (xn--) and back.

Tool processing runs in your browser. If you create a calculator or conversion share link, its values are included in the URL. See the privacy policy for account, analytics and advertising data.

Current Limits

  • Maximum input length: 100,000 characters

Shows the xn-- form that DNS and certificates really use for internationalized domain names (IDNs) such as 한국.kr, and converts back.

It only converts notation; it does not check registration or reachability.

What You Can Do

Domain → IDN (xn--)
Turns a domain with non-ASCII characters into an ASCII address.
IDN (xn--) → domain
Turns an xn-- address back into readable characters.
Unicode ↔ Punycode
Converts a single label to a Punycode string.

How to Use Punycode / IDN Converter

  1. 1
    Choose a taskPick the direction.
  2. 2
    Enter a domainThe full dot-separated domain.
  3. 3
    CopyPaste into config files or a certificate request.

Examples

Korean domain to xn--
Input: 한국.kr
Result: xn--3e0b707e.kr
xn-- back to Korean
Input: xn--3e0b707e.kr
Result: 한국.kr

Common Use Cases

  • Setting DNS records or TLS certificates for an IDN
  • Reading xn-- addresses in mail headers or logs
  • Checking lookalike phishing domains

Frequently Asked Questions (FAQ)

What about plain English domains?

ASCII-only labels come back unchanged.

Why convert to xn--?

DNS handles ASCII only, so IDNs are registered and looked up as xn-- addresses internally.

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