Punycoder

Punycoder is a Python tool to encode Unicode domain names into Punycode (IDNA) format and decode Punycode back into Unicode. It is useful for anyone working with Internationalized Domain Names (IDNs).

See: RFC 3490 - Internationalizing Domain Names in Applications (IDNA)

Features

• Encode Unicode domain names to Punycode.
• Decode Punycode domain names back to Unicode.
• Command-line interface (CLI)
• Lightweight, dependency-free, Pythonic
• Compatible with Python 3.5+

Usage

Encode a Unicode domain to Punycode:

./punycoder -e café.com
# Output: xn--caf-dma.com

Decode a Punycode domain to Unicode:

./punycoder -d xn--caf-dma.com
# Output: café.com

Invalid inputs are printed to stderr:

./punycoder -d xn--invalid--domain
# Error: decoding with 'idna' codec failed (UnicodeError: Violation of BIDI requirement 2)