🌐 Punycode Converter
Convert international domain names to Punycode and back. IDN domain encoding.
About the Punycode Converter
This tool converts internationalized domain names (IDN) between Unicode and Punycode (ACE form) in both directions. Type a domain like 例え.jp and click To Punycode to get xn--r8jz45g.jp. All conversion happens in your browser.
What is Punycode?
Punycode is a specialized encoding defined in RFC 3492 that maps Unicode strings into the limited ASCII character set allowed by the Domain Name System. DNS only understands ASCII letters, digits and hyphens, so any non-ASCII label (Chinese, Japanese, Cyrillic, emoji, etc.) must be encoded as xn-- followed by a Punycode sequence before it can be resolved.
How it works
The "To Punycode" direction uses your browser's built-in URL parser, which converts each non-ASCII label to its xn-- form per IDNA2008. The "From Punycode" direction runs a small in-page Punycode decoder (RFC 3492) to expand the xn-- labels back into Unicode.
Frequently asked questions
Does the tool only convert the hostname? Yes. It operates on the domain portion; if you paste a full URL, only the hostname is taken via the URL constructor.
What about subdomains? Each label is converted independently, so a domain like テスト.例え.jp becomes xn--zckzah.xn--r8jz45g.jp.
Can I trust the output? The encoding matches what browsers and DNS resolvers expect, but for production use always verify against your registrar's tooling.