Punycode (IDN) Domain Encoder & Decoder (RFC 3492)
Convert internationalized domain names (IDN) to ASCII xn-- Punycode and vice-versa.
Execution runs 100% locally inside the browser sandbox using HTML5 Canvas, Web Cryptography Subtle API, and Web Workers. No data is ever transmitted across the network.
Zero network latency. Operates completely offline with zero dependencies on third-party backend servers or cloud services.
Built according to official RFC specifications, cryptographic test vectors, and enterprise-grade data transformation standards.
How to Use Punycode (IDN) Domain Encoder & Decoder (RFC 3492)
Choose Unicode to Punycode or Punycode to Unicode decoding mode.
Paste one or multiple domain names (one per line) into the input box.
Copy the RFC 3492 compliant Punycode or Unicode domain list with 1-click.
Frequently Asked Questions
What is Punycode and why is it used?
Punycode is an encoding syntax defined in RFC 3492 that translates Unicode characters into the limited ASCII character set supported by the global Domain Name System (DNS).
How do I recognize a Punycode domain?
Punycode encoded domain labels always start with the prefix 'xn--' (for example, münchen.de becomes xn--mnchen-3ya.de).
Related Unit & Code Converters Tools
View all →Calculate exact file download & transfer times across bandwidth speeds.
Convert Bytes, KB, MB, GB, TB, PB with binary vs decimal bases.
Convert CSV to JSON and JSON to CSV with custom delimiters and exports.
Encode plain text to Base64 or decode Base64 back to text.