Punycode Converter

Overview

• Converts an internationalized domain name (IDN) containing Japanese text, emoji, or similar into Punycode notation (starting with xn--), which uses only ASCII characters, or does the reverse.
• Each dot-separated label (subdomain part) is converted individually, so you can enter a full domain, such as example.co.jp, as-is.
• Since DNS can only handle ASCII characters, domain names containing non-ASCII characters are internally managed in Punycode format. This tool reproduces that conversion rule in your browser.

Usage

1. Enter a domain name into the input field.
2. Click "Convert to Punycode" or "Convert to Unicode".
3. The result is displayed below.

Example

日本語.jp

xn--wgv71a119e.jp

Use Cases

• Checking the Punycode notation that will actually be registered in DNS before acquiring or configuring a Japanese domain
• Converting an xn-- domain shown in a browser's address bar or server log back into its actual domain name (such as Japanese text)
• Verifying that conversion results match the specification while implementing or debugging a system that handles internationalized domain names

FAQ

Notes

• If you "Convert to Unicode" a label that already consists only of ASCII characters, that label is returned unchanged.
• Conversion is applied per dot-separated label, so you can enter a full domain, including subdomains, as-is.
• Entering a malformed Punycode string (one that cannot be decoded) results in an error.