opt-gif(1) General Commands Manual opt-gif(1)
NAME
opt-gif - losslessly optimize GIF image files
SYNOPSIS
opt-gif [-h(elp)] [-f filelist] [-p(ipe)] [-q(uiet)] [-t(ouch)]
[-T threads] file...
DESCRIPTION
opt-gif losslessly optimizes GIF images by removing unused palette
entries. This is accomplished using the gifsicle utility.
OPTIONS
-h Print help and quit.
-f file_list
Read the names of files to be processed from the specified file.
-p Read the names of files to be processed from stdin.
-q Quiet output. No output commentary will be printed.
-t Preserve timestamp on modified files.
-T threads
Process up to the specified number of files in parallel. The
default value is half the multi-threading capability of the CPU,
i.e., half the sibling count as listed in /proc/cpuinfo.
EXAMPLES
Optimize a couple of image files:
opt-gif image001.gif image002.gif
Optimize all GIF images in an directory tree, utilizing half of all
cores: find . -name "*.gif" -print | opt-gif -p
Fully utilize a quad-core system while optimizing all GIF images:
find . -name "*.gif" -print | opt-gif -p -T 4
NOTES
If opt-gif appears to be malfunctioning, try running it in single-
threaded mode by using the -T 1 option. This permits more meaningful
error messages to be printed.
WARNING
If your copy of the gifsicle utility was compiled without LZW support,
this utility won't work. Specifically, it will fail to reduce image
sizes at all, leaving them unchanged. [Versions of gifsicle without
LZW support were intended to avoid infringing on Unisys' LZW patents.
These patents expired in the United States on 2003-06-20, in Europe on
2004-06-18, and in Japan on 2005-06-19. If you have such a version,
get a more recent copy with LZW support enabled.] Even if your copy of
gifsicle does work properly, the best solution is still to convert all
of your GIF images to PNG, as PNG images are almost always smaller.
SEE ALSO
gifsicle(1)
COPYRIGHT
Copyright (C) 2004-2026 by Brian Lindholm. This program is free
software; you can use it, redistribute it, and/or modify it under the
terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
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.
littleutils 2026 Jan 01 opt-gif(1)
littleutils 1.4.0 - Generated Wed Feb 18 07:28:36 CST 2026