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Punycode / IDN Converter

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

Runs instantly in your browser — results update as you type.

What is Punycode?

Punycode is the encoding that lets domain names contain non-ASCII characters such as ü, é, 中文 or emoji. It converts each label to an ASCII form starting with xn-- — for example münchen.de becomes xn--mnchen-3ya.de — because DNS only supports plain letters, digits and hyphens.

How internationalised domain names work

Internationalised domain names (IDNs) let people register domains in their own script: Arabic, Chinese, Cyrillic, Hindi, Sinhala and more. The DNS system, however, still only understands ASCII. Browsers therefore convert each part of the domain with the IDNA standard and Punycode (RFC 3492) before looking it up, then show the readable Unicode form to the user — when it is safe to do so.

Examples

UnicodePunycode
münchen.dexn--mnchen-3ya.de
例え.jpxn--r8jz45g.jp
bücher.examplexn--bcher-kva.example

Only labels with non-ASCII characters are encoded; .de and .jp stay as they are.

Why you might need this

  • DNS and hosting panels often require the xn-- form when you add an IDN.
  • SSL certificates list the Punycode version in their Subject Alternative Names.
  • Email and server logs show xn-- domains; decode them to read them.
  • Security checks — homograph attacks use look-alike characters, such as Cyrillic "а" instead of Latin "a", to imitate brands. Converting a suspicious domain to Punycode reveals the trick: a real apple.com has no xn-- label.

SEO notes for IDNs

Google indexes IDNs normally and shows them in Unicode to users in the matching language. Use the Unicode form in your content and social profiles, and keep canonical tags, sitemaps and redirects consistent — browsers send the Punycode form, so servers and analytics usually record it.

This converter accepts bare domains or full URLs, one per line, and runs in your browser. Inspect a full URL with the URL Parser or check an IDN's DNS records with the DNS Records Checker.

Frequently asked questions

What does xn-- mean in a domain?

xn-- is the prefix that marks a Punycode-encoded label. It tells browsers and DNS that the label represents non-ASCII characters.

How do I convert an IDN to Punycode?

Paste the domain or URL, one per line. The converter shows the Punycode (ASCII) form and the Unicode form side by side.

Are IDN domains bad for SEO?

No. Google supports them and shows them in Unicode to local users. They can be harder to type for international audiences, so many brands also own an ASCII version.

What is an IDN homograph attack?

It is a phishing trick that uses look-alike characters from other alphabets to imitate a real domain. Converting to Punycode exposes it with an xn-- label.

Does it work with full URLs?

Yes. Paste a full URL and the hostname is converted while the protocol and path are kept.