About Punycode Converter
Punycode is an encoding scheme that converts Unicode characters into ASCII, purpose-built for Internationalized Domain Names (IDN). Because the DNS system was originally ASCII-only, any domain containing Chinese, Japanese, Korean, Cyrillic, Arabic or other non-ASCII characters must be converted to a Punycode form prefixed with `xn--` before DNS can resolve it. For example, the domain `中文.com` becomes `xn--fiq228c.com`. This tool performs both encoding and decoding entirely in your browser, supporting any Unicode character including emoji, with instant conversion and no network calls. Whether you are registering an IDN, debugging mail server IDN support, or troubleshooting DNS resolution, you get accurate Punycode results immediately. All processing happens locally — your domains never leave your device.
How to Use
- Open the Punycode Converter tool page
- Enter or paste your data into the input area
- View the real-time results and use the copy button to get the output
Use Cases
- IDN Registration — Convert domains with Chinese, Japanese or other non-ASCII characters into Punycode for registrar lookup and registration.
- Mail Server Debugging — SMTP requires ASCII domains; convert IDN domains to troubleshoot delivery failures and SPF/DKIM mismatches.
- DNS Resolution Issues — Compare the Unicode domain a user typed with the actual Punycode being resolved to pinpoint failures or hijacking.
- Certificate Configuration — Generate CSRs or configure SAN entries for IDN using the Punycode form of the domain for correct matching.
- Development Self-Test — Quickly verify Punycode output when integrating IDN in front-end or back-end code, catching encoding bugs early.
FAQ
What is Punycode?
Punycode (RFC 3492) is an algorithm that encodes Unicode strings into ASCII, used to represent Internationalized Domain Names in the ASCII-only DNS system.
Why do domains start with xn--?
`xn--` is the ACE (ASCII Compatible Encoding) prefix. DNS resolvers use it to detect a Punycode-encoded IDN and decode it back to Unicode for display.
Does it support emoji domains?
Yes. Emoji are Unicode characters and can be Punycode-encoded. Whether you can actually register one depends on the top-level registry allowing emoji.
Is my domain uploaded?
No. All encoding and decoding runs locally in your browser with no network requests, so your domain never leaves your device.
Why are some encoded domains so long?
Punycode length depends on the number and complexity of Unicode characters. More characters and higher code points produce longer ASCII output.
Can I convert in bulk?
This tool converts one domain at a time instantly. For bulk processing, paste entries one by one or use a standard Punycode library in a script.
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