You may often see and use images in JPG, PNG or TIFF format. They are nearly everywhere in our daily life and work. However, if you are engaged in software industry, you may sometimes noticed another image format, ICO. As it seldom appears on the internet, you may be curious about what it is. Read this post to have a comprehensive understanding of ICO.

ICO file

What Is An ICO File?

ICO is an image file format for storing computer icons for Windows operating systems. It can be explained as computer icons container. An ICO file is usually used to represent a Windows application, a website, browser, file, or file folder. Every executable that needs to display on Windows like the Start Menu have its icon in ICO format.

ICO files has the .ico filename extension. Different from other image formats, ICO doesn't seem to be in any image reader's list of output formats. The common way to create an ICO file is to change the original image file extension to .ico or use a file converter. If you are a Photoshop user, a plugin will be required to easily make an ICO file with the image editor.

Microsoft introduced the ICO file format in 1985 in Windows 1.0. The benefit of the format is that it can store multiple icon images in various sizes and contain different resolutions and bit depths.

How to Open ICO File

Since ICO files are images, they can be opened and viewed by most image viewers. Here are some of programs to open an ICO file.

Microsoft Photos (built into Windows)

Microsoft Paint 3D (built-into Windows)

Apple Preview (built into macOS)

Inkscape (Windows, Mac and Linux): open-source and free

Google Photos (Web)

How to Convert PNG to ICO

When you have designed a logo in PNG format, you can easily convert PNG to ICO format to upload the logo. The most straightforward way as mentioned is to manually alter the file extension. But this may make the resulting file incompatible with some programs.

To convert a PNG to an ICO image, you can resort to a dedicated file converter. Open the image converter, add the PNG picture, select the output format as ICO, and click the Convert button. An ICO converter often lets you perform batch tasks. It is particularly suitable for those who have multiple PNG images to convert.



Charlotte has been in the software industry for 8+ years. She works for AWZWARE now as a passionate writer. She is good at providing simple guides to use various video, office and entertainment software. Charlotte also recommends many other useful tools to make your work and life easier. A food lover too.