Punycode Converter
Punycode (ACE)
RFC 3492 Punycode. Each non-ASCII label gets the xn-- ACE prefix (IDNA).
Punycode Converter — Free Online Tool
Encodes and decodes internationalized domain name labels with Punycode (RFC 3492), converting Unicode domain labels to their ACE (xn--) form and back — useful for validating IDN registrations, debugging email sender domains, and understanding how browsers map multilingual domains to DNS-safe ASCII.
How to use the Punycode Converter
- Open the tool above — it runs entirely in your browser, so your input never leaves this page.
- Paste or type your input into the field, then press the relevant button (e.g. Encode / Decode, Generate, or Convert).
- Copy the result from the output area with the copy button orCtrl/Cmd + C.
- No signup, no upload, and no tracking — repeat as often as you need.
Frequently asked questions
Is the Punycode Converter free to use?
Yes. The Punycode Converter is completely free, with no signup, no ads inside the tool, and no hidden limits.
Does the Punycode Converter upload my data?
No. The Punycode Converter processes everything locally in your browser. Your input is never sent to a server, so it stays private even on shared devices.
Does the Punycode Converter work offline?
After the page loads, the Punycode Converter runs entirely in your browser, so it keeps working without a network connection.
Free & private — why use this Punycode Converter
The Punycode Converter runs 100% client-side in your browser. Your data is never uploaded to a server, no account is required, and the tool is completely free. It works offline once the page has loaded and is part of a growing collection of privacy-first developer utilities.