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.ICO File Extension

File TypeIcon File

4.1 (79 Votes)
CategorySystem Files


This file is saved in a binary format, which requires a specific program to read its contents.

What is an ICO file?

An ICO file is an image format used to store icons for Windows programs, files, and folders. It contains two bitmaps: 1) the AND bitmap - the image mask (which determines what part of the icon is transparent) and 2) the XOR bitmap - contains the icon which is mapped onto the image mask. ICO files can be modified to create custom icons.

More Information

Screenshot of a .ico file in File Viewer Plus 2

ICO file open in File Viewer Plus 2

The "favicon.ico" file is used to store a small website logo that appears in the address bar of a Web browser. If a website has a favion.ico image, it will appear to the left of the Web address when any page of the website is loaded. The favicon.ico image file must be 16x16 pixels and stored in the root directory of the website in order for the Web browser to recognize it.

An ICO file is similar to a Windows cursor (.CUR) file, but has a different identification byte in the header.

Common ICO Filenames

favicon.ico - A 16x16 pixel .PNG file located in the root directory of a website and containing a small icon graphic to be displayed in the Web browser's address bar.

Open and view .ICO files with File Viewer Plus.
Programs that open ICO files
Updated 3/22/2018

About ICO Files

Our goal is to help you understand what a file with a *.ico suffix is and how to open it.

The Icon file type, file format description, and Mac, Windows, Linux, and Android programs listed on this page have been individually researched and verified by the FileInfo team. We strive for 100% accuracy and only publish information about file formats that we have tested and validated.

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