Punycode Converter

Domain names with accents or non-Latin scripts are stored in DNS as ASCII Punycode labels that start with xn--. Convert names in either direction to configure DNS records, certificates or mail servers, or to see which real domain a suspicious xn-- link points to.

Encoding & Security Runs in your browser

Convert Domain Names

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How to Use the Punycode Converter

Choose Unicode to Punycode or the reverse.
Enter one domain, URL host or e-mail address per line.
Press Convert.
Read each result and its notes, or copy the converted list.

About This Tool

Web administrators setting up international domains, security teams checking look-alike (homograph) links, and developers handling IDNs.

Input: Domain names · Output: Punycode or Unicode.

Features and Limitations

Features

RFC 3492 Punycode with the IDNA xn-- prefix, label by label.
Accepts full URLs and e-mail addresses (only the domain is converted).
Normalises to lowercase NFC and recognises ideographic full stops.
Flags labels over 63 characters and names over 253.

Limitations

Uses lowercase plus NFC normalisation rather than the complete UTS #46 mapping, so a few special characters (for example ß or some symbols) may convert differently than in browsers.
It does not check whether a domain is registered or allowed by a registry.
The local part of an e-mail address is not converted.
Results are computed in your browser; nothing you enter is sent to a server.

Example

münchen.de becomes xn--mnchen-3ya.de, and 例え.テスト becomes xn--r8jz45g.xn--zckzah.

Frequently Asked Questions

What is Punycode?

An encoding defined in RFC 3492 that represents Unicode characters using only letters, digits and hyphens, so international domain names work in DNS.

How can Punycode help spot phishing?

Look-alike domains may use Cyrillic or Greek letters that resemble Latin ones. Converting reveals an xn-- form, showing the name is not the plain ASCII domain it imitates.

Why must labels be at most 63 characters?

That is a DNS limit for each part of a name, applied to the ASCII (xn--) form.

Is anything looked up online?

No. Conversion is pure calculation in your browser; no DNS queries are made.