Format
Icon file format
Summary
- Name
- Icon file format
- Identifiers
-
- Apple Uniform Type Identifier: com.microsoft.ico
- MIME: image/x-icon
- PUID: x-fmt/418
- Format type
- Image (Raster)
- Description
- This is an outline record only, and requires further details, research or authentication to provide information that will enable users to further understand the format and to assess digital preservation risks associated with it if appropriate. If you are able to help by supplying any additional information concerning this entry, please return to the main PRONOM page and select ‘Add an Entry’.
- File extensions
-
ico - Source
- Digital Preservation Department / The National Archives
Internal signatures
Icon file format
- Note
- Header: (00000100) followed by number of images used in file. For purposes of this signature, range of limited to 1-9 - the largest number of images that was observed in any Icon file used for testing was 8. Header sequence followed by image directory, then sequence (000028000000{2}0000{2}00000100[01:20]0000000000)
Byte sequences
- Min Frag Length
- Absolute from BOF
- Offset
- 0
- Max offset
- None
- Byte Sequence
00000100[01:09]00{3}00[00:01]00{1}00{3}00*000028000000{2}0000{2}00000100[01:20]0000000000- Endianness
- None
Changelog
-
Updated in V74
- Release date
- 31 March 2014
Icon file format: Merged BOF and VAR sequences to avoid offset issue identified by Ross Spencer.
-
Updated in V55
- Release date
- 4 January 2012
Icon file format: Identifier information added.
-
Added in V49
- Release date
- 5 April 2011
Icon File Format: Signature developed through PRONOM Research.