Change Icon For File Type Mac

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Often, ICO files are converted to and from other file types to use certain images as icons or to save the icon image into an editable or portable format. A popular program for manipulating ICO files is GNU Image Manipulation Program. ICO is supported by Mac, Linux, and Windows operating systems. However looking at the same icons for months or years on end can get repetitive and old. In this article we’ll go over a few ways to spice up the look of the folder, file, application and dock icons. Change Icons Method #1 – Get Info. The first method in changing the icons I’m going to show you is through the “Get Info” window. The file icon is always provided by the application handling opening a file by default. Preview provides PDF icons by default, and PNG icons, but if you change all PNG files to open using Pixelmator instead, these files get a Pixelmator-style icon afterwards. What you need to do is add your file type definition to the application. Jun 25, 2018 Icons on the Mac represent everything starting from a file, folder, applications etc. And you might wish to change them at some point. You can go for changing the icon to make it look your way. You can go for changing the icon to make it look your way. Nov 14, 2018 Note: If you find icons online in the.icns format, you can drag these icon types directly onto the icon in a file or folder's Info panel, thereby skipping the Preview steps described below.

Apple Icon Image
Filename extension
Type codeicns
Uniform Type Identifier (UTI)
Developed byApple Inc.
Type of format

The Apple Icon Image format is the icon format used in Apple Inc.'s macOS. It supports icons of 16 × 16, 32 × 32, 48 × 48, 128 × 128, 256 × 256, 512 × 512 points at 1x and 2x scale, with both 1- and 8-bitalpha channels and multiple image states (example: open and closed folders). The fixed-size icons can be scaled by the operating system and displayed at any intermediate size.

File structure[edit]

The file format consists of an 8 byte header, followed by any number of icons.


04Magic literal, must be 'icns' (0x69, 0x63, 0x6e, 0x73)
44Length of file, in bytes, msb first

Icon data[edit]

04Icon type, see OSType below.
44Length of data, in bytes (including type and length), msb first
8VariableIcon data


012711281128 bytes
1282551 byte3130 copies
Change Icon For File Type Mac

Over time the format has been improved and there is support for compression of some parts of the pixel data. The 32-bit ('is32', 'il32', 'ih32','it32') and ARGB ('ic04', 'ic05') pixel data are often compressed (per channel) with a format similar to PackBits.[1]Some sources mentioned that the OS supports both compressed or uncompressed data chunks.

The following pseudocode decompresses the data:

Example: 02 01 02 02 80 03 81 04 82 05 should decompress to 01 02 02 03 03 03 04 04 04 04 05 05 05 05 05

Icon types[edit]

OSTypeLength (bytes)Size (pixels)Supported OS VersionDescription
ICON128321.032×32 1-bit mono icon
ICN#256326.032×32 1-bit mono icon with 1-bit mask
icm#48166.016×12 1 bit mono icon with 1-bit mask
icm496167.016×12 4 bit icon
icm8192167.016×12 8 bit icon
ics#64 (32 img + 32 mask)166.016×16 1-bit mask
ics4128167.016×16 4-bit icon
ics8256167.016x16 8 bit icon
is32varies (768)168.516×16 24-bit icon
s8mk256168.516x16 8-bit mask
icl4512327.032×32 4-bit icon
icl81,024327.032×32 8-bit icon
il32varies (3,072)328.532x32 24-bit icon
l8mk1,024328.532×32 8-bit mask
ich#288488.548×48 1-bit mask
ich41,152488.548×48 4-bit icon
ich82,304488.548×48 8-bit icon
ih32varies (6,912)488.548×48 24-bit icon
h8mk2,304488.548×48 8-bit mask
it32varies (49,152)12810.0128×128 24-bit icon
t8mk16,38412810.0128×128 8-bit mask
icp4varies1610.716x16 icon in JPEG 2000 or PNG format
icp5varies3210.732x32 icon in JPEG 2000 or PNG format
icp6varies6410.764x64 icon in JPEG 2000 or PNG format
ic07varies12810.7128x128 icon in JPEG 2000 or PNG format
ic08varies25610.5256×256 icon in JPEG 2000 or PNG format
ic09varies51210.5512×512 icon in JPEG 2000 or PNG format
ic10varies102410.71024×1024 in 10.7 (or [email protected] 'retina' in 10.8) icon in JPEG 2000 or PNG format
ic11varies3210.8[email protected] 'retina' icon in JPEG 2000 or PNG format
ic12varies6410.8[email protected] 'retina' icon in JPEG 2000 or PNG format
ic13varies25610.8[email protected] 'retina' icon in JPEG 2000 or PNG format
ic14varies51210.8[email protected] 'retina' icon in JPEG 2000 or PNG format
ic04varies1616x16 ARGB
ic05varies3232x32 ARGB
  • the values inside the brackets () in the length column is the uncompressed length.
  • the ARGB format consists of the ascii values for 'ARGB' and the four compressed channels tightly packed

Other types[edit]

OSTypeLength (bytes)Description
'TOC 'varies'Table of Contents' a list of all image types in the file, and their sizes (added in Mac OS X 10.7)
'icnV'44-byte big endian float - equal to the bundle version number of Icon that created to icon
'info'259Info binary plist. Usage unknown


Various image viewers can load *.icns files, and free and open source converters from or to PNG also exist.[2][3]GTK+ can load *.icns resources since 2007.[4] Other tools supporting the format include the Apple Icon Composer and icns Browser, The Iconfactory, and IconBuilder.
MacOS[clarification needed] offers the built-in iconutil command line tool to pack and unpack *.icns files.

External links[edit]

  • IconFamily – Open source Objective C class to read and write Apple icns files
  • osxiconutils - Command line tools to work with Apple icns files

See also[edit]

  • ICO format on Windows
  • X PixMap format for X11


  1. ^Macintosh Icons
  2. ^'libicns'. SourceForge project icns. 2009. Retrieved August 18, 2016.
  3. ^'png2icns'. Moin Uddin. 2016. Retrieved May 25, 2017.
  4. ^Lyonel Vincent (2007). 'Mac OS X icons for GTK+'. Retrieved August 18, 2016.
Retrieved from ''

It is a good way to customize your own Windows OS and improve the using experience by changing the icons on Windows 10. If you are bored with the default icons on your Windows 10 computer, you can use the following ways to change icons on Windows 10 easily.

1. Change Desktop Icons on Windows 10


Step 1: Click Start > select Settings > choose Personalization click Themes.

How To Change File Type

Step 2: Slide the left pane and locate to Related Settings. Then choose Desktop icon settings.

Step 3: In the Desktop Icon Settings window, select the desktop icon you want to change and click Change Icon.

Step 4: Choose a new icon from the list or click Browse to input an icon and tap OK.

Tip: The icon type can be exe, dll, or ico.

Step 5: Click OK to confirm the change.

2. Change Folder Icons on Windows 10

Step 1: Right-click the folder and select Properties in the context menu.

Step 2: Choose Customize and click Change Icon in the Properties window.

Step 3: You can replace the folder icon with a basic/personalized one. Then click OK to save the change.

Step 4: Hit OK to finish changing the folder icon.

3. Change a Type of File's Icon on Windows 10

Different from personalizing desktop icons or folder icons, changing the icon of a type of file needs the help of the third-party tool like File Types Manager and here it will be used as the utility.

Step 1: Get File Types Manager on your Windows 10 PC.

Step 2: Find the file type that you want to change its icon. Then close the Find box.

Step 3: Right-click the file and choose Edit Selected File Type.

Step 4: Click the 3-dots button in the pop-out window.

Mac Os Change Icon

Step 5: Pick one of the existing icons. You can also input your own icon by clicking Browse > click OK.

Step 6: At last, don't forget to click OK to execute the operation.

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