ot2kpx - Man Page

extract kerning information from OpenType fonts


ot2kpx [ -afm | -kpx | -lua ] <fontfile>


ot2kpx extract the kerning data from OpenType fonts and prints it to stdout, either in Adobe's KPX format (for adding to an afm file) or as a Luatex custom feature, for use with the \directlua command.

Options and Arguments


Print a short help text and exit.


Print ot2kpx's version and exit.

-afm,  -kpx

Output the kerning data in Adobe's KPX format, as used in afm files. This is the default output format.


Output the kerning data as a Luatex custom font feature, to be included in a \directlua command.


The OpenType font (both otf and ttf format are supported).



Marc Penninga <marcpenninga@gmail.com>


This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version. A copy of the GNU General Public License is included with ot2kpx; see the file GPLv2.txt.


This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.


This document describes ot2kpx version 20230201.

Recent Changes

(See the source code for the rest of the story.)


Added the -version option.


Added the -lua command-line option to get output in Luatex's custom feature format.


2023-02-01 fontools Marc Penninga