Every option has a long form, ‘--long-descriptive-name’. You don't need to type the whole long descrip‐
tive name, just enough to make it unambiguous.
Some options also have a short form, ‘-X’. You can combine short options if they don't take arguments:
‘-IIb’ is the same as ‘-I-I-b’. But be careful with options that do take arguments: ‘-cblah’ means ‘-c
blah’, not ‘-c-b-l-a-h’.
Many options also have a converse, ‘--no-option’, which turns off the option. You can turn off a short
option ‘-X’ by saying ‘+X’ instead.
ModeOptions
Mode options tell gifsicle what kind of output to generate. There can be at most one, and it must precede
any GIF inputs.
--merge, -m
Combine all GIF inputs into one file with multiple frames and write that file to the standard out‐
put. This is the default mode.
--batch, -b
Modify each GIF input in place by reading and writing to the same filename. (GIFs read from the
standard input are written to the standard output.)
--explode, -e
Create an output GIF for each frame of each input file. The output GIFs are named ‘xxx.000’,
‘xxx.001’, and so on, where ‘xxx’ is the name of the input file (or whatever you specified with
‘--output’) and the numeric extension is the frame number.
--explode-by-name, -E
Same as --explode, but write any named frames to files ‘xxx.name’ instead of ‘xxx.frame-number’.
Frames are named using the ‘--name’ option.
GeneralOptions
General options control the information gifsicle prints and where it writes its output. The info options
and --verbose can be turned off with ‘--no-X’.
--info, -I
Print a human-readable description of each input GIF to the standard output, or whatever file you
specify with -o. This option suppresses normal output, and cannot be combined with mode options
like --batch. If you give two --info or -I options, however, information is printed to standard er‐
ror, and normal output takes place as usual.
--color-info, --cinfo
Like --info, but also print information about input files' colormaps.
--extension-info, --xinfo
Like --info, but also print any unrecognized GIF extensions in a hexdump(1)-like format.
--size-info, --sinfo
Like --info, but also print information about compressed image sizes.
--help, -h
Print usage information and exit.
-ofile--outputfile
Send output to file. The special filename ‘-’ means the standard output.
--verbose, -V
Print progress information (files read and written) to standard error.
--no-warnings, -w
Suppress all warning messages.
--no-ignore-errors
Exit with status 1 when encountering a very erroneous GIF. Default is to muddle on.
--version
Print the version number and some short non-warranty information and exit.
--careful
Write slightly larger GIFs that avoid bugs in some other GIF implementations. Some Java and Internet
Explorer versions cannot display the correct, minimal GIFs that Gifsicle produces. Use the --careful
option if you are having problems with a particular image.
--conserve-memory
Conserve memory usage at the expense of processing time. This may be useful if you are processing
large GIFs on a computer without very much memory. Or say --no-conserve-memory.
--nextfile
Allow input files to contain multiple concatenated GIF images. If a filename appears multiple times
on the command line, gifsicle will read a new image from the file each time. This option can help
scripts avoid the need for temporary files. For example, to create an animated GIF with three frames
with different delays, you might run "gifsicle--nextfile-d10--d20--d30->out.gif" and write
the three GIF images, in sequence, to gifsicle's standard input.
--multifile
Like --nextfile, but read asmanyGIFimagesaspossible from each file. This option is intended for
scripts. For example, to merge an unknown number of GIF images into a single animation, run "gifsi‐cle--multifile->out.gif" and write the GIF images, in sequence, to gifsicle's standard input.
Any frame selections apply only to the last file in the concatenation.
FrameSelections
A frame selection tells gifsicle which frames to use from the current input file. They are useful only
for animations, as non-animated GIFs only have one frame. Here are the acceptable forms for frame speci‐
fications.
#num Select frame num. (The first frame is ‘#0’. Negative numbers count backwards from the last
frame, which is ‘#-1’.)
#num1-num2 Select frames num1 through num2.
#num1- Select frames num1 through the last frame.
#name Select the frame named name.
The ‘#’ character has special meaning for many shells, so you generally need to quote it.
For example,
gifsiclehappy.gif"#0"
uses the first frame from happy.gif;
gifsiclehappy.gif"#0-2"
uses its first three frames; and
gifsiclehappy.gif"#-1-0"
uses its frames in reverse order (starting from frame #-1 -- the last frame -- and ending at frame #0 --
the first).
The action performed with the selected frames depends on the current mode. In merge mode, only the se‐
lected frames are merged into the output GIF. In batch mode, only the selected frames are modified; other
frames remain unchanged. In explode mode, only the selected frames are exploded into output GIFs.
FrameChangeOptions
Frame change options insert new frames into an animation or replace or delete frames that already exist.
Some things -- for example, changing one frame in an animation -- are difficult to express with frame se‐
lections, but easy with frame changes.
--deleteframes [frames...]
Delete frames from the input GIF.
--insert-beforeframeother-GIFs
Insert other-GIFs before frame in the input GIF.
--appendother-GIFs
Append other-GIFs to the input GIF.
--replaceframesother-GIFs
Replace frames from the input GIF with other-GIFs.
--done
Complete the current set of frame changes.
The frames arguments are frame selections (see above). These arguments always refer to frames from the
original input GIF. So, if ‘a.gif’ has 3 frames and ‘b.gif’ has one, this command
gifsiclea.gif--delete"#0"--replace"#2"b.gif
will produce an output animation with 2 frames: ‘a.gif’ frame 1, then ‘b.gif’.
The other-GIFs arguments are any number of GIF input files and frame selections. These images are com‐
bined in merge mode and added to the input GIF. The other-GIFs last until the next frame change option,
so this command replaces the first frame of ‘in.gif’ with the merge of ‘a.gif’ and ‘b.gif’:
gifsicle-bin.gif--replace"#0"a.gifb.gif
This command, however, replaces the first frame of ‘in.gif’ with ‘a.gif’ and then processes ‘b.gif’ sepa‐
rately:
gifsicle-bin.gif--replace"#0"a.gif--doneb.gif
Warning: You shouldn't use both frame selections and frame changes on the same input GIF.
ImageOptions
Image options modify input images -- by changing their interlacing, transparency, and cropping, for exam‐
ple. Image options have three forms: ‘--X’, ‘--no-X’, and ‘--same-X’. The ‘--X’ form selects a value for
the feature, the ‘--no-X’ form turns off the feature, and the ‘--same-X’ form means that the feature's
value is copied from each input. The default is always ‘--same-X’. For example, -background="#0000FF"
sets the background color to blue, --no-background turns the background color off (by setting it to 0),
and --same-background uses input images' existing background colors. You can give each option multiple
times; for example,
gifsicle-b-O2-ia.gif--same-interlaceb.gifc.gif
will make ‘a.gif’ interlaced, but leave ‘b.gif’ and ‘c.gif’ interlaced only if they were already.
-Bcolor--backgroundcolor
Set the output GIF's background to color. The argument can have the same forms as in the --trans‐parent option below.
--cropx1,y1-x2,y2--cropx1,y1+widthxheight
Crop the following input frames to a smaller rectangular area. The top-left corner of this rectangle
is (x1,y1); you can give either the lower-right corner, (x2,y2), or the width and height of the rec‐
tangle. In the x1,y1+widthxheight form, width and height can be zero or negative. A zero dimension
means the cropping area goes to the edge of the image; a negative dimension brings the cropping area
that many pixels back from the image edge. For example, --crop 2,2+-2x-2 will shave 2 pixels off
each side of the input image. Cropping takes place before any rotation, flipping, resizing, or posi‐
tioning.
--crop-transparency
Crop any transparent borders off the following input frames. This happens after any cropping due to
the --crop option. It works on the raw input images; for example, any transparency options have not
yet been applied.
--flip-horizontal--flip-vertical
Flip the following frames horizontally or vertically.
-i--interlace
Turn interlacing on.
-Swidthxheight--logical-screenwidthxheight
Set the output logical screen to widthxheight. --no-logical-screen sets the output logical screen
to the size of the largest output frame, while --same-logical-screen sets the output logical screen
to the largest input logical screen. --screen is a synonym for --logical-screen.
-px,y--positionx,y
Set the following frames' positions to (x,y). --no-position means --position 0,0. Normally, --po‐sitionx,y places every succeeding frame exactly at x,y. However, if an entire animation is input,
x,y is treated as the position for the animation.
--rotate-90--rotate-180--rotate-270
Rotate the following frames by 90, 180, or 270 degrees. --no-rotate turns off any rotation.
-tcolor--transparentcolor
Make color transparent in the following frames. Color can be a colormap index (0-255), a hexadeci‐
mal color specification (like "#FF00FF" for magenta), or slash- or comma-separated red, green and
blue values (each between 0 and 255).
ExtensionOptions
Extension options add non-visual information to the output GIF. This includes names, comments, and gener‐
ic extensions.
--app-extensionapp-nameextension
Add an application extension named app-name and with the value extension to the output GIF.
--no-app-extensions removes application extensions from the input images.
-ctext--commenttext
Add a comment, text, to the output GIF. The comment will be placed before the next frame in the
stream. --no-comments removes comments from the input images.
--extensionnumberextension
Add an extension numbered number and with the value extension to the output GIF. Number can be in
decimal, octal, hex, or it can be a single character like ‘n’, whose ASCII value is used. --no-ex‐tensions (or +x) removes extensions from the input images.
-ntext--nametext
Set the next frame's name to text. This name is stored as an extension in the output GIF (extension
number 0xCE, followed by the characters of the frame name). --no-names removes name extensions from
the input images.
AnimationOptions
Animation options apply to GIF animations, or to individual frames in GIF animations. As with image op‐
tions, most animation options have three forms, ‘--X’, ‘--no-X’, and ‘--same-X’, and you can give anima‐
tion options multiple times; for example,
gifsicle-ba.gif-d50"#0""#1"-d100"#2""#3"
sets the delays of frames 0 and 1 to 50, and frames 2 and 3 to 100.
-dtime--delaytime
Set the delay between frames to time in hundredths of a second.
-Dmethod--disposalmethod
Set the disposal method for the following frames to method. A frame's disposal method determines
how a viewer should remove the frame when it's time to display the next. Method can be a number be‐
tween 0 and 7 (although only 0 through 3 are generally meaningful), or one of these names: none
(leave the frame visible for future frames to build upon), asis (same as "none"), background (or bg)
(replace the frame with the background), or previous (replace the frame with the area from the pre‐
vious displayed frame). --no-disposal means --disposal=none.
-l[count]
--loopcount[=count]
Set the Netscape loop extension to count. Count is an integer, or forever to loop endlessly. If you
supply a --loopcount option without specifying count, Gifsicle will use forever. --no-loopcount
(the default) turns off looping.
Set the loop count to one less than the number of times you want the animation to run. An animation
with --no-loopcount will show every frame once; --loopcount=1 will loop once, thus showing every
frame twice; and so forth. Note that --loopcount=0 is equivalent to --loopcount=forever, not
--no-loopcount.
-O[level]
--optimize[=level]
Attempt to shrink the file sizes of GIF animations. Level determines how much optimization is done;
higher levels take longer, but may have better results. There are currently three levels:
-O1 Store only the changed portion of each image. This is the default.
-O2 Store only the changed portion of each image, and use transparency.
-O3 Try several optimization methods (usually slower, sometimes better results).
Other optimization flags provide finer-grained control.
-Okeep-empty
Preserve empty transparent frames (they are dropped by default).
You may also be interested in other options for shrinking GIFs, such as -k, --lossy, and --no-exten‐sions. Note that -O does not guarantee to shrink file size, and in rare cases, even -O3 may actual‐
ly enlarge file size.
-U--unoptimize
Unoptimize GIF animations into an easy-to-edit form.
GIF animations are often optimized (see --optimize) to make them smaller and faster to load, which
unfortunately makes them difficult to edit. --unoptimize changes optimized input GIFs into unopti‐
mized GIFs, where each frame is a faithful representation of what a user would see at that point in
the animation.
ImageTransformationOptions
Image transformation options apply to entire GIFs as they are read or written. They can be turned off
with ‘--no-option’.
--resizewidthxheight
Resize the output GIF to the given width and height. If width or height is an underscore ‘_’, that
dimension is chosen so that the aspect ratio remains unchanged. Resizing happens after all input
frames have been combined and before optimization. Resizing uses logical screen dimensions; if the
input stream has an unusual logical screen (many GIF displayers ignore logical screens), you may
want to provide --no-logical-screen (or +S) to reset it so gifsicle uses image dimensions instead.
See also --resize-method.
--resize-widthwidth--resize-heightheight
Resize to a given width or height, preserving aspect ratio. Equivalent to --resizewidthx_ or --re‐size _xheight.
--resize-fitwidthxheight--resize-touchwidthxheight
Resize the output GIF to fit within a rectangle with dimensions widthxheight. The aspect ratio re‐
mains unchanged. The --resize-fit option only shrinks the image—no resize is performed if the GIF
already fits within the rectangle. Either width or height may be an underscore ‘_’, which leaves
that dimension unconstrained.
--resize-fit-widthwidth--resize-fit-heightheight--resize-touch-widthwidth--resize-touch-heightheight
Like --resize-fit and --resize-touch, but constrains only one dimension.
--scaleXfactor[xYfactor]
Scale the output GIF's width and height by Xfactor and Yfactor. If Yfactor is not given, it de‐
faults to Xfactor. Scaling happens after all input frames have been combined and before optimiza‐
tion.
--resize-methodmethod
Set the method used to resize images. The ‘sample’ method runs very quickly, but when shrinking im‐
ages, it produces noisy results. The ‘mix’ method is somewhat slower, but produces better-looking
results. The default method is currently ‘mix’.
Details: The resize methods differ most when shrinking images. The ‘sample’ method is a point sam‐
pler: each pixel position in the output image maps to exactly one pixel position in the input. When
shrinking, full rows and columns from the input are dropped. The other methods use all input pixels,
which generally produces better-looking images. The ‘box’ method, a box sampler, is faster than the
more complex filters and produces somewhat sharper results, but there will be anomalies when shrink‐
ing images by a small amount in one dimension. (Some output pixels will correspond to exactly 1 in‐
put row or column, while others will correspond to exactly 2 input rows or columns.) The ‘mix’
method is a full bilinear interpolator. This is slower and produces somewhat blurrier results, but
avoids anomalies.
Gifsicle also supports more complex resamplers, including Catmull-Rom cubic resampling (‘catrom’),
the Mitchell-Netravali filter (‘mitchell’), a 2-lobed Lanczos filter (‘lanczos2’), and a 3-lobed
Lanczos filter (‘lanczos3’). These filters are slower still, but can give sharper, better results.
--resize-colorsn
Allow Gifsicle to add intermediate colors when resizing images. Normally, Gifsicle's resize algo‐
rithms use input images' color palettes without changes. When shrinking images with very few colors
(e.g., pure black-and-white images), adding intermediate colors can improve the results. Example:
--resize-colors64 allows Gifsicle to add intermediate colors for images that have fewer than 64 in‐
put colors.
ColorOptions
Color options apply to entire GIFs as they are read or written. They can be turned off with ‘--no-op‐tion’.
-knum--colorsnum
Reduce the number of distinct colors in each output GIF to num or less. Num must be between 2 and
256. This can be used to shrink output GIFs or eliminate any local color tables.
Normally, an adaptive group of colors is chosen from the existing color table. You can affect this
process with the --color-method option or by giving your own colormap with --use-colormap. Gifsicle
may need to add an additional color (making num+1 in all) if there is transparency in the image.
--color-methodmethod
Determine how a smaller colormap is chosen. ‘diversity’, the default, is xv(1)'s diversity algo‐
rithm, which uses a strict subset of the existing colors and generally produces good results.
‘blend-diversity’ is a modification of this: some color values are blended from groups of existing
colors. ‘median-cut’ is the median cut algorithm described by Heckbert. --method is a synonym for
--color-method.
-f--dither[=method]
When --dither is on and the colormap is changed, combinations of colors are used to approximate
missing colors. This looks better, but makes bigger files and can cause animation artifacts, so it
is off by default.
Specify a dithering algorithm with the optional method argument. The default, ‘floyd-steinberg’,
uses Floyd-Steinberg error diffusion. This usually looks best, but can cause animation artifacts,
because dithering choices will vary from frame to frame. Gifsicle also supports ordered dithering
algorithms that avoid animation artifacts. The ‘ro64’ mode uses a large, random-looking pattern and
generally produces good results. The ‘o3’, ‘o4’, and ‘o8’ modes use smaller, more regular patterns.
The ‘ordered’ mode chooses a good ordered dithering algorithm. For special effects, try the halftone
modes ‘halftone’, ‘squarehalftone’, and ‘diagonal’. Some modes take optional parameters using com‐
mas. The halftone modes take a cell size and a color limit: ‘halftone,10,3’ creates 10-pixel wide
halftone cells where each cell uses up to 3 colors.
--gammagamma
Set the gamma correction to gamma, which can be a real number or ‘srgb’. Roughly speaking, higher
numbers exaggerate shadows and lower numbers exaggerate highlights. The default is the function de‐
fined by the standard sRGB color space, which usually works well. (Its effects are similar to --gam‐ma=2.2.) Gifsicle uses gamma correction when choosing a color palette (--colors) and when dithering
(--dither).
--lossy[=lossiness]
Alter image colors to shrink output file size at the cost of artifacts and noise. Lossiness deter‐
mines how many artifacts are allowed; higher values can result in smaller file sizes, but cause more
artifacts. The default lossiness is 20.
--change-colorcolor1color2
Change color1 to color2 in the following input GIFs. (The color arguments have the same forms as in
the -t option.) Change multiple colors by giving the option multiple times. Color changes don't in‐
terfere with one another, so you can safely swap two colors with ‘--change-colorcolor1color2--change-colorcolor2color1’. They all take effect as an input GIF is read. --no-change-color
cancels all color changes.
--transform-colormapcommandCommand should be a shell command that reads from standard input and writes to standard output. Each
colormap in the output GIF is translated into text colormap format (see --use-colormap below) and
piped to the command. The output that command generates (which should also be in text colormap for‐
mat) will replace the input colormap. The replacement doesn't consider color matching, so pixels
that used color slot n in the input will still use color slot n in the output.
--use-colormapcolormap
Change the image to use colormap. Each pixel in the image is changed to the closest match in col‐ormap (or, if --dither is on, to a dithered combination of colors in colormap). Colormap can be web
for the 216-color “Web-safe palette”; gray for grayscale; bw for black-and-white; or the name of a
file. That file should either be a text file (the format is described below) or a GIF file, whose
global colormap will be used. If --colors=N is also given, an N-sized subset of colormap will be
used.
Text colormap files use this format:
; each non-comment line represents one color, "red green blue"
; each component should be between 0 and 255
0 0 0 ; like this
255 255 255
; or use web hex notation
#ffffff ; like this
Install Now
PNG Icons
