idn(1)

idn1

Internationalized domain names command line tool

Usage

idn [OPTION] ... [STRINGS] ...

Overview

Internationalized Domain Name (IDN) convert STRINGS, or standard input.

Command line interface to the internationalized domain name library.

All strings are expected to be encoded in the preferred charset used by your locale. Use --debug to find out what this charset is. You can override the charset used by setting environment variable CHARSET.

To process a string that starts with '-', for example '-foo', use '--' to signal the end of parameters, as in: idn --quiet -a -- -foo

Mandatory arguments to long options are mandatory for short options too.

-h, --help

Print help and exit

-V, --version

Print version and exit

-s, --stringprep

Prepare string according to nameprep profile

-d, --punycode-decode

Decode Punycode

-e, --punycode-encode

Encode Punycode

-a, --idna-to-ascii

Convert to ACE according to IDNA (default mode)

-u, --idna-to-unicode

Convert from ACE according to IDNA

--allow-unassigned

Toggle IDNA AllowUnassigned flag (default off)

--usestd3asciirules

Toggle IDNA UseSTD3ASCIIRules flag (default off)

--no-tld

Don't check string for TLD specific rules Only for --idna-to-ascii and --idna-to-unicode

-n, --nfkc

Normalize string according to Unicode v3.2 NFKC

-p, --profile=STRING

Use specified stringprep profile instead Valid stringprep profiles: Nameprep iSCSI Nodeprep Resourceprep trace SASLprep

--debug

Print debugging information

--quiet

Silent operation

Releases

12 releases since Debian 3.1 (Sarge); the text changed 11 times.

  1. 3.1
  2. 4.0
  3. 5.0
  4. 6.0
  5. 7
  6. 8
  7. 9
  8. 10
  9. 11
  10. 12
  11. 13
  12. Arch

--nfkc since Debian 5.0 (Lenny); --no-tld since Debian 6.0 (Squeeze); -n since Debian 5.0 (Lenny).

--tld until Debian 5.0 (Lenny); -t until Debian 5.0 (Lenny).

Author

Written by Simon Josefsson.

Reporting bugs

Report bugs to: [email protected]
GNU Libidn home page: <https://www.gnu.org/software/libidn/>
General help using GNU software: <https://www.gnu.org/gethelp/>

From libidn 1.44-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.