Skip to content
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
201 lines (145 sloc) 9.18 KB


Crate Minimum rustc version License

A simple command-line tool to generate application icons from raster graphics or vector graphics images.

Quickly combine multiple images and create professional-looking icons for most versions of Windows, macOS, iOS & Linux. Powered by IconBaker.


  • Simple interface.
  • Sane defaults for the domain of icon composition.
  • Supports outputting to stdout, allowing for piping.
  • Available as a single executable.


An icon consists of a set of entries. An entry is simply an image that has a particular size. For example, this is an icon that has a 32x32 entry, a 64x64 entry and a 128x128 entry:


What does it do?

Notice that, in the example above, most entries are basically the same picture re-scaled to multiple sizes. IconPie simply automates the process of re-scaling the picture and combining those re-scaled entries into an icon.

How does it do it?


When re-scaling pictures, IconPie preserves their original aspect-ratios. It also ensures that the all re-scaled images are square, by adding transparent borders if necessary. If the picture presents a transparent background, the transparency is preserved in the re-scaled images.

Adding Transparent Borders


For raster graphics (jpeg, png, ...), IconPie uses nearest-neighbor interpolation by default, optimizing for small-resolution images.

Furthermore, when using nearest-neighbor interpolation, it only up-scales images on an integer scale, preserving as much detail as possible.

Default Resample

You can choose to opt-out of the default interpolation scheme for raster graphics by specifying a resampling filter with the -r flag, as described in the Usage section.

For vector graphics (svg), IconPie always uses linear interpolation regardless of any specified resampling filter. Vector graphics are also rasterized with antialiasing.


The formal docopt syntax for using IconPie is as follows:

  • icon-pie icns ((-e | --entry) <file path> <size>... [(-r | --resample) (nearest | linear | cubic)])... [(-o | --output) <path>]
  • icon-pie ico ((-e | --entry) <file path> <size>... [(-r | --resample) (nearest | linear | cubic)])... [(-o | --output) <path>]
  • icon-pie favicon ((-e | --entry) <file path> <size>... [(-r | --resample) (nearest | linear | cubic)])... [--apple-touch] [--web-app] [(-o --output) <path>]
  • icon-pie (-h | --help)
  • icon-pie (-v | --version)


  • -e FILE (SIZE)..., --entry FILE (SIZE)... — Specify an entry's source image and target sizes.
  • -r FILTER, --resample FILTER — Specify a re-sampling filter: nearest, linear or cubic. If no filter is specified the app defaults to nearest.
  • -o PATH, --output PATH — Specify an output path. This is optional. If absent the output is directed to stdout.
  • --apple-touch — Favicon specific option. Confire the output to include link tags for apple-touch icons in the HTML helper.
  • --web-app — Favicon specific option. Confire the output to include a .webmanifest helper for PWA icons.
  • -h, --help — Help.
  • -v, --version — Display version information.


Let's say you have the following files saved at your file system.

Source Files

We'll walk trought some practical examples of IconPie usage.

Simple Usage

Take big.svg, resize it to 32x32, 64x64 and 128x128. Then save it at icon.ico.

$ icon-pie ico -e big.svg 32 64 128 -o icon.ico

Example 1

Sampling From Multiple Files

Take small.png, resize it to 32x32 and 64x64. Then take big.svg and resize it 128x128. Then combine the re-scaled entries in icon.icns.

$ icon-pie icns -e small.png 32 64 -e big.svg 128 -o icon.icns

Example 2

Specifying a Resampling Filter

Take small.png, resize it to 32x32 and 64x64 using linear interpolation. Then take big.svg and resize it 128x128. Then combine the re-scaled entries into a favicon scheme.

$ icon-pie favicon -e small.png 64 128 -r linear -o ./favicon/

Example 3


<link rel="icon" type="image/png" sizes="64x64" href="icons/favicon-0.png">
<link rel="icon" type="image/png" sizes="128x128" href="icons/favicon-1.png">


Icon Formats

This are the icon formats IconPie can output to:

  • ico
  • icns
  • favicon

Icns Support

OSType Description Supported?
ICON 32×32 1-bit entry No
ICN# 32×32 1-bit entry with 1-bit mask No
icm# 16×12 1-bit entry with 1-bit mask No
icm4 16×12 4-bit entry No
icm8 16×12 8-bit entry No
ics# 16×16 1-bit mask No
ics4 16×16 4-bit entry No
ics8 16x16 8-bit entry No
is32 16×16 24-bit entry Yes
s8mk 16x16 8-bit mask Yes
icl4 32×32 4-bit entry No
icl8 32×32 8-bit entry No
il32 32x32 24-bit entry Yes
l8mk 32×32 8-bit mask Yes
ich# 48×48 1-bit mask No
ich4 48×48 4-bit entry No
ich8 48×48 8-bit entry No
ih32 48×48 24-bit entry Yes
h8mk 48×48 8-bit mask Yes
it32 128×128 24-bit entry Yes
t8mk 128×128 8-bit mask Yes
icp4 16x16 32-bit png/jp2 entry png only
icp5 32x32 32-bit png/jp2 entry png only
icp6 64x64 32-bit png/jp2 entry png only
ic07 128x128 32-bit png/jp2 entry png only
ic08 256×256 32-bit png/jp2 entry png only
ic09 512×512 32-bit png/jp2 entry png only
ic10 512x512@2x "retina" 32-bit png/jp2 entry png only
ic11 16x16@2x "retina" 32-bit png/jp2 entry png only
ic12 32x32@2x "retina" 32-bit png/jp2 entry png only
ic13 128x128@2x "retina" 32-bit png/jp2 entry png only
ic14 256x256@2x "retina" 32-bit png/jp2 entry png only

Image Formats

This are the formats IconPie can use as input:

Format Supported?
png All supported color types
jpeg Baseline and progressive
gif Yes
bmp Yes
ico Yes
tiff Baseline(no fax support), lzw, PackBits
webp Lossy(Luma channel only)
pnm pbm, pgm, ppm, standard pma
svg Static SVG Full 1.1


Licensed under MIT license(LICENSE-MIT or


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be licensed as above, without any additional terms or conditions.

Feel free to help out! Contributions are welcomed 😃

You can’t perform that action at this time.