How to Convert ICO to ICNSby Diana Braun
The ".ico" file extension identifies an icon file on a Windows computer. If you want to use that same icon file on a Mac computer, you must convert it to an ICNS file, which is the file type associated with icons on a Mac. An online icon conversion tool can help you easily convert an icon file from the ICO extension to a Mac-compatible ICNS file.
Launch a Web browser and navigate to a website that offers an icon conversion tool such as Iconverticons.com.
Convert your ICO file using the "Browse" feature of the site.
Click the “Convert” button.
Click the “Save” button when prompted to save the converted ICNS file locally to your computer.